Recent Advances in the Chemical Synthesis of C-Glycosides

Review pubs.acs.org/CR

Recent Advances in the Chemical Synthesis of C‑Glycosides You Yang*,† and Biao Yu*,‡ †

Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China ‡ State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China ABSTRACT: Advances in the chemical synthesis of C-pyranosides/furanosides are summarized, covering the literature from 2000 to 2016. The majority of the methods take advantage of the construction of the glycosidic CC bond. These C-glycosylation methods are categorized herein in terms of the glycosyl donor precursors, which are commonly used in O-glycoside synthesis and are easily accessible to nonspecialists. They include glycosyl halides, glycals, sugar acetates, sugar lactols, sugar lactones, 1,2-anhydro sugars, thioglycosides/sulfoxides/sulfones, selenoglycosides/telluroglycosides, methyl glycosides, and glycosyl imidates/phosphates. Mechanistically, C-glycosylation reactions can involve glycosyl electrophilic/cationic species, anionic species, radical species, or transition-metal complexes, which are discussed as subcategories under each type of sugar precursor. Moreover, intramolecular rearrangements, such as the Claisen rearrangement, Ramberg−Bäcklund rearrangement, and 1,2-Wittig rearrangement, which usually involve concerted pathways, constitute another category of Cglycosylations. An alternative to the C-glycosylations is the formation of pyranoside/ furanoside rings after construction of the predetermined glycosidic CC bonds, which might involve cyclization of acyclic precursors or D−A cycloadditions. Throughout, the stereoselectivity in the formation of the resultant C-glycosidic linkages is highlighted. 5.1. C-Glycosylation with 1,2-Anhydro Sugars through Glycosyl Electrophilic/Cationic Species 5.2. C-Glycosylation with 1,2-Anhydro Sugars through Glycosyl Radical Species 6. C-Glycosylation with Thioglycosides, Sulfoxides, and Sulfones 6.1. C-Glycosylation with Thioglycosides, Sulfoxides, and Sulfones through Glycosyl Electrophilic/Cationic Species 6.2. C-Glycosylation with Thioglycosides, Sulfoxides, and Sulfones through Glycosyl Anionic Species 7. C-Glycosylation with Selenoglycosides and Telluroglycosides 8. C-Glycosylation with Sugar Lactols 9. C-Glycosylation with Sugar Lactones 10. C-Glycosylation with Glycosyl Imidates and Phosphates 11. C-Glycosylation with 1-O-Methyl Sugars 12. Synthesis of C-Glycosides through Rearrangement of Sugar Precursors 13. Synthesis of C-Glycosides with Acyclic Substrates 14. Synthesis of C-Glycosides with Miscellaneous Substrates

CONTENTS 1. Introduction 2. C-Glycosylation with Glycosyl Halides 2.1. C-Glycosylation with Glycosyl Halides through Glycosyl Electrophilic/Cationic Species 2.2. C-Glycosylation with Glycosyl Halides through Glycosyl Anionic Species 2.3. C-Glycosylation with Glycosyl Halides through Glycosyl Radical Species 2.4. C-Glycosylation with Glycosyl Halides through Transition-Metal Complexes 3. C-Glycosylation with Glycals 3.1. C-Glycosylation with Glycals through Glycosyl Electrophilic/Cationic Species 3.2. C-Glycosylation with Glycals through Glycosyl Anionic Species 3.3. C-Glycosylation with Glycals through Radical Species 3.4. C-Glycosylation with Glycals through Transition-Metal Complexes 4. C-Glycosylation with Glycosyl Acetates 4.1. C-Glycosylation with Glycosyl Acetates through Glycosyl Electrophilic/Cationic Species 4.2. C-Glycosylation with Glycosyl Acetates through Glycosyl Anionic Species 5. C-Glycosylation with 1,2-anhydro sugars © 2017 American Chemical Society

12282 12286

12286 12288 12288 12289 12292 12293 12300 12300 12300 12305

12305 12309 12309

12310 12311 12313

12314

12314 12315 12317 12318 12321 12323 12323 12324 12331

Received: May 1, 2017 Published: September 15, 2017 12281

DOI: 10.1021/acs.chemrev.7b00234 Chem. Rev. 2017, 117, 12281−12356

Chemical Reviews 15. Conclusions Author Information Corresponding Authors ORCID Notes Biographies Acknowledgments References

Review

involve cyclization, oxygenation, reduction, dehydration, and Oglycosylation, furnishing a large family of structurally diverse Cglycosides. Apart from biosynthesis, chemical synthesis serves as a powerful tool for obtaining sufficient amounts of the homogeneous C-glycosides to understand the structure−activity relationships of C-glycosides. Listed in Figure 2 are representative natural C-glycosides that have been synthesized since 1990. They include showdomycin,27 (+)-varitriol,28 (−)-neodysiherbaine A,29 (+)-ambruticin S,30 bergenin,31 papulacandin D,32 aspalathin,33 puerarin,34 mangiferin,35 chafuroside A,36 ravidomycin,37 gilvocarcin M,38 cassialoin,39 medermycin,40 saptomycin B,41 and antibiotic 100-1.42 The last molecule in the figure, kendomycin, which bears a tetraalkyl-substituted pyran motif, is conventionally not deemed a glycoside; however, a relevant Cglycosylation method is employed in its synthesis.43 Indeed, Cglycosides are frequently utilized as chiral building blocks for the synthesis of natural products containing various pyran/furan motifs.44−48 Because of the extremely diverse structures of the naturally occurring C-glycosides and the even more diverse O-glycosides, which require replacement with C-glycosidic linkages, a vast array of methods have been developed for the synthesis of these biologically significant molecules. The methods reported prior to 2000 have been summarized in a few comprehensive reviews.49−53 After 2000, review articles on the synthesis of Cglycosides have mainly focused on specific topics, such as exoglycals,54,55 C-oligosaccharides,56,57 C-glycoconjugates,58 C-aryl glycosides,17,59,60 C-nucleosides,61,62 C-mannopyranosides,63 βC-glycosides,64 nucleophilic C-glycosyl donors,65−67 and crosscoupling reactions.68,69 Before 2009, the recent developments of C-glycosylation reactions were summarized in a few book chapters.70−72 Herein, we provide a comprehensive review on the topic of C-glycoside synthesis with a focus on the reactions leading directly to C-glycosides, covering the literature reported from 2000 to 2016.

12335 12337 12337 12337 12337 12337 12338 12338

1. INTRODUCTION A C-glycoside is a compound with a carbohydrate unit attached to an aglycone or another carbohydrate unit through a CC bond linkage, instead of the usual CO glycosidic acetal linkage. Because C-glycosides are inert toward the hydrolytic enzymes in vivo, they have become routine choices for artificial surrogates/ mimics of the native O-glycosides as potential therapeutic agents.1−7 Successful examples in recent years include the development of a series of SGLT2 inhibitors against type II diabetes (e.g., dapagliflozin, canagliflozin, and empagliflozin),8−12 as well as Pro-Xylane as a popular antiaging cosmetic agent (Figure 1).13,14 The C-analogues of KRN7000 and blood group H-antigen are metabolically stable while showing the desired biological activities.6,7,15 On the other hand, a wide variety of C-glycosides occur as natural products that show significant biological activities.16 The biosynthesis of C-glycosides stems from the construction of a variety of aglycone precursors through a series of enzymatic processes such as the acetate−malonate pathway, the shikimic acid pathway, and the mixed acetate−malonate−shikimic acid pathway.17−20 C-Glycosylation of the resulting aglycone precursors with a nucleoside diphosphate sugar under the catalysis of C-glycosyltransferase leads to formation of the Cglycoside skeletons, in which the aryl-C-glycosides are suggested to be formed through a Friedel−Crafts-like alkylation pathway.21−26 Late-stage modifications of the C-glycoside skeletons

Figure 1. Replacement of the native O-glycosidic linkage with a C-glycosidic linkage as a successful strategy to develop metabolically stable carbohydrate drugs. 12282


Chemical Reviews

Review

Figure 2. Representative natural C-glycosides that have been synthesized since 1990.

In the present review, we first categorize the C-glycosylation methods based on the glycosyl donor precursors. These include glycosyl halides, glycals, glycosyl acetates, 1,2-anhydro sugars, thioglycosides/sulfoxides/sulfones, selenoglycosides/telluroglycosides, sugar lactols, sugar lactones, glycosyl imidates/ phosphates, and methyl glycosides. Such sugar derivatives are fruequently used in O-glycoside synthesis and are easily accessible. Thus, they would be convenient starting points for nonspecialists when encountering a quest for C-glycoside synthesis. Under each category of glycosyl donors, the methods are further classified based on the plausible reaction mechanisms, if applicable. Nevertheless, the reaction mechanisms have rarely been validated by experiments and could be elusive. For instance, transition-metal-mediated cross-coupling reactions might proceed through a radical pathway rather than through a reductive elimination pathway from a metal complex intermediate. For each C-glycoside synthesis, the stereoselectivity poses a major

The majority of the methods for C-glycoside synthesis take advantage of the direct formation of glycosidic CC linkages with carbohydrate building blocks as the “donor” precursors (Figure 3). Such glycosyl donors can undergo C-glycosylation reactions through electrophilic/cationic species (route a), anionic species (route b), radical species (route c), or transition-metal complexes (route d). C-Glycosylation reactions involving intramolecular rearrangements, such as Claisen rearrangement, Ramberg−Bäcklund rearrangement, and 1,2Wittig rearrangement, which usually proceed through concerted pathways, are also feasible (route e). A completely different alternative to these C-glycosylations for C-glycoside synthesis is the construction of pyranoside/furanoside rings after installation of the predetermined glycosidic CC bonds (route f). These mechanistic considerations were also employed in the previous reviews to classify the various methods for C-glycoside synthesis. 12283


Chemical Reviews

Review

Figure 3. Major chemical methods for the synthesis of C-glycosides. 12284


Chemical Reviews

Review

Scheme 1. Plausible Mechanistic Schemes for C-Glycosylation with Glycosyl Halides

Scheme 2. C-Alkylation with Glycosyl Bromides

formation of the C-glycosides are presented; preparation of the advanced precursors and subsequent elaboration into the target C-glycosides are not discussed. (2) Only C-pyranosides and

challenge, and this issue is intensively discussed throughout this review. Furthermore, the following points regarding the present review should be noted: (1) Only the reactions leading to the 12285


Chemical Reviews

Review

-furanosides are included; the C-glycosides of iminosugars,73,74 carbasugars,75 and thiasugars76 are beyond the scope of this review. (3) The synthesis of C-oligosaccharides and Cglycoconjugates, which has been reviewed recently,56−58 is largely excluded.

stereoselectivity outcomes of the resulting C-glycosides are highly dependent on the substrate structures and the metal catalysts. 2.1. C-Glycosylation with Glycosyl Halides through Glycosyl Electrophilic/Cationic Species

Treatment of peracetyl glucopyranosyl α-bromide 1 with Hg(CN)2 in the melt state gave β-cyanide 2 (41%), with CH2(CN)2 and cyanoacetate in the presence of NaH in dimethylformamide (DMF) leading to β-C-glycosides 5 and 6 in ∼60% yields (Scheme 2).90−93 The reversal of the anomeric configuration from α-bromide to β-glycoside under basic conditions implies an SN2 reaction pathway. The reaction of a mixture of the glycosyl α/β-bromides 3 with Hg(CN)2 at 80 °C led to β-cyanide 4 in a comparable yield of 57%.94 This stereoselectivity can be attributed to the neighboring participation in the glycosylation, which proceeds through a glycosyl cationic species in acidic conditions. Remarkably, C-glycosylation of peracetyl di- and trisaccharide α-bromides 7 and 8 with allylmagnesium bromide proceeded smoothly, after acetylation of the resultant hydroxyl groups, to stereoselectively provide β-Cglycosides 9 and 10, respectively, in ∼84% yields.95,96 Moreover, aryl and heteroarylzinc reagents can be used to react with glycosyl bromides (Scheme 3).97,98 Treatment of glucopyranosyl α-bromide 11 with a panel of diaryl zinc reagents at 90 °C led to C-aryl β-glucosides 12−15 in 50−86% yields.97 The β-selectivity might be due to the strong participation capability of the C-2 pivaloyl group; however, an SN2 reaction pathway could not be ruled out. Notably, when bromide 11 was subjected to meta-anisylzinc species 16 in toluene at 85 °C and then quenched with aqueous ammonium chloride, a significant amount of the cine-substitution product 18 (β/α = 5:1), which was obtained through the Friedel−Crafts reaction, was observed in addition to the expected coupling product 17 (β/α = 34:1) (Scheme 4).98 With electron-rich aromatic compounds, such as indoles and pyrroles, as C-nucleophiles, C-glycosylation with glycosyl bromides proceeded at 0 °C or room temperature under the activation of InCl3 (Scheme 5).99 The desired C-glycosides (19− 25) were obtained in 65−82% yields, with the 1,2-trans-anomers as the predominant products (1,2-trans-/cis-anomer > 9:1) because of the neighboring participation effect. Not surprisingly, the glycosylation of pyrrole led to a pair of regioisomers (25a and 25b), confirming the Friedel−Crafts-type reaction pathway operating in the C-glycosylation. Similarly, glycosyl chlorides can undergo C-glycosylation with cyanides and Grignard reagents (Scheme 6). Treatment of glucosaminyl α-chloride 26 with KCN under phase-transfer conditions gave β-cyanide 27 in 39% yield.100 Substitution of arabinosyl α-chloride 28 with allylmagnesium bromide afforded C-arabinoside 29 as a mixture of the anomers (∼73%, β/α = 4:1), whereas reaction of 2-deoxyribosyl α-chloride 30 with arylmagnesium bromide led to C-glycoside 31 (51%, β/α = 1:3) in favor of the α-anomer.101−103 C-Glycosylation of 2-thio(p-tolyl)-glucopyranosyl chloride 32 with 2-methylthiophene

2. C-GLYCOSYLATION WITH GLYCOSYL HALIDES Glycosyl halides, including glycosyl bromides, chlorides, fluorides, and iodides, which are among the most commonly Scheme 3. C-Glycosylation of Arylzinc Reagents with Glucosyl Bromide

used donors for O-glycosylation,77,78 are frequently applied in Cglycosylation.49−53 Conditions similar to those used for Oglycosylation can be used for the coupling of glycosyl halides with C-nucleophiles to afford C-glycosides. As reported in the early literature,79−81 these C-glycosylation reactions can proceed through glycosyl electrophilic/cationic species, for instance, an SN2-like substitution of a glycosyl bromide/iodide or a contact ion pair by C-nucleophiles, or through a solvent-separated ion pair analogous to those involved in the SN1-type O-glycosylation (Scheme 1a).78 The latter pathway dominates in the Cglycosylation of glycosyl chlorides and fluorides. Additionally, it has long been known that glycosyl bromides/chlorides can easily be transformed into glycosyl anionic species (A or B) by mostly reductive metalation, with transmetalations sometimes being employed to modify the reactivity of the glycosyl anions (Scheme 1b);67 condensation of the glycosyl anionic species in situ with C-electrophiles usually leads to C-glycosides with retention of the configuration of the anomeric anions.65,67,82 Also, glycosyl radicals can be derived from glycosyl halides in the presence of radical initiators, where the axial σ-radical (C) is usually more stable and more nucleophilic than the corresponding equatorial σ-radical (D) because of the anomeric effect that arises from the interaction between the anomeric radical and the lone electron pair on the ring oxygen (Scheme 1c).66,83,84 The resulting axial σ-radical (C) can undergo C-glycosylation with radical acceptors, such as electron-deficient olefins, providing αC-glycosides favorably.65,66,85−87 Recently, transition-metalmediated cross-coupling with glycosyl bromides/chlorides has become a feasible alternative for C-glycosylation through the intermediate E, typically involving oxidative addition and reductive elimination pathways (Scheme 1d).68,69,88,89 The

Scheme 4. C-Glycosylation of meta-Anisylzinc Reagent with Glucosyl Bromide

12286


Chemical Reviews

Review

Scheme 5. C-Glycosylation of Indole and Pyrrole Derivatives with Glycosyl Bromides

Scheme 6. C-Glycosylation with Glycosyl Chlorides

amounts of O-glycosylated products (Scheme 8).112 α-CGlycoside 51 could be readily isomerized into β-C-glycoside 52 in quantitative yield through a 1,8-diazabicyclo[5.4.0]undec7-ene- (DBU-) promoted ring opening−recyclization process. It should be noted that the O-glycosides obtained in this glycosylation could not undergo O → C rearrangement effectively because of the electron-deficient nature of the aromatic aglycone. In contrast, coupling of perbenzyl glucopyranosyl fluoride 53 with phenol 54 in the presence of BF3·OEt2 led to O-glycosides that could be simultaneously rearranged into the desired β-C-aryl glycoside 55 (85%).113 Treatment of fluoride 53 with other aryl nucleophiles under similar conditions also provided the corresponding β-C-aryl glycosides in an efficient manner.114−122 Fluoride 53 reacted with allenyl tributylstannane in the presence of BF3·OEt2, giving propargyl C-glycoside 56 (57%) with poor stereoselectivity (α/β = 65:35).123 Indium-mediated alkynylation of fluoride 53 with 1-

using Zn(CN)2 as a promoter might proceed through an episulfonium-like intermediate (A), providing β-C-glucoside 33 in 60% yield.104−106 Interestingly, treatment of permethyl-, perbenzyl-, and isopropylidene-protected pyranosyl and furanosyl chlorides 34−37 with alkyl or phenyl lithium reagents led to C-1 alkyl/ aryl glycals 38−49 in good yields (Scheme 7),107−110 wherein the resultant C-glycosides underwent deprotonation at the anomeric position and subsequent elimination of the 2-ether substituent. Glycosyl fluorides are stable donors for C-glycosylation.111 The glycosylation possibly proceeds through a glycosyl cationic species, so that the stereoselectivity is highly dependent on the coupling partners and the reaction conditions. Thus, glycosylation of perbenzyl galactopyranosyl fluoride 50 with 4hydroxyl-6-methylpyrone under the promotion of boron trifluoride diethyl etherate (BF3·OEt2) led to a mixture of α-Cglycoside 51 (56%) and β-C-glycoside 52 (5%), as well as minor 12287


Chemical Reviews

Review

Scheme 7. C-Glycosylation of Organolithium Reagents with Glycosyl Chlorides

glycoside 78 exclusively in 73% yield. These results demonstrate that the conformation of the transition state of the sugar moiety has a strong influence on the stereoselectivity of a glycosylation. The use of glycosyl iodides for C-glycosylation is rare because of the instability of these compounds.128−130 Coupling of perbenzylated galactosyl iodide 79 with vinylmagnesium bromide in the presence of tetrabutylammonium iodide (TBAI) in toluene at 110 °C afforded α-C-vinyl galactoside 80 (79%) as the predominant product (α/β = 12:1) (Scheme 11).131 A series of functional transformations on 80 enabled the synthesis of the Canalogue 81 of bacterial glycolipid BbGL2. 2.2. C-Glycosylation with Glycosyl Halides through Glycosyl Anionic Species

Reductive metalation of glycosyl halides gave rise to nucleophilic glycosyl anions that could be trapped by electrophiles to provide C-glycosides in a stereoselective manner.65,67,132 As an example, conversion of hemiacetal into a dilithium intermediate (A) through glycosyl chloride 82 followed by exposure to CO2 provided α-C-carboxylic acid 83 in 66% yield (Scheme 12).133 Reductive samariation of the in situ generated glycosyl iodide 84 with SmI2 led to an organosamarium(III) species (B) that reacted with aldehyde 85 to give β-C-disaccharide 86 in 66% yield.134,135 It was reported that the 2-deoxyglycosyl phosphonium salt prepared from glycosyl halide was subjected to benzaldehyde through Wittig olefination to afford exo-glycal in moderate yield.136 The Reformatsky-type reaction of 2ketohexosyl bromide 87 with diacetonegalactose-6-aldehyde 88 in the presence of copper-activated zinc followed by βelimination of benzoate using NaHCO3 gave the corresponding α-C-glycoside 89 in 73% yield.137 2.3. C-Glycosylation with Glycosyl Halides through Glycosyl Radical Species

iodo-2-phenylacetylene afforded α-C-glycoside 57 as the major anomer (α/β = 4:1) (Scheme 8).124 BF3·OEt2-promoted Callylation of 2,3-O-(3-pentylidene)-D-ribofuranosyl fluoride 58 with allyltrimethylsilane provided C-riboside 59 in an excellent βselective manner (86%, β/α > 98/2), which can be explained by an unusual outside attack of the nucleophile on the transition state (A) because of the steric hindrance at the inside face.125 C-Glycosylation of glycosyl fluorides with organotrifluoroborates under the promotion of BF3·OEt2 provided alkynyl and alkenyl C-glycosides in high yields and good stereoselectivities (Scheme 9).28 With perbenzyl manno-, gluco-, galacto-, and peracetyl-2-deoxyglucopyranosyl fluorides as donors, the coupling with potassium alkynyl trifluoroborates bearing aromatic and aliphatic substituents afforded C-glycosides 57 and 60−66 in good yields (53−94%) with high α-selectivities (from α/β = 5.6:1 to α only). Under similar conditions, D-mannofuranosyl and D-arabinofuranosyl fluoride led to alkynyl α-C-glycosides 69 and 70 exclusively, whereas D-ribofuranosyl fluoride and Lfuranosyl fluoride favored the formation of alkynyl β-Cglycosides 67 and 68. Compared to alkynyl trifluoroborates, alkenyl trifuoroborates led to the corresponding α-C-mannopyranosides 71 and 72 in lower yields but with comparable stereoselectivities. Based on the α/β ratio for various sugar units, it was suggested that the stereoselectivity might arise from the varied conformations of the glycosyl oxonium intermediates.126 BF3·OEt2-promoted C-glycosylation of perbenzyl xylosyl fluoride 73 with allyltrimethylsilane afforded C-glycoside 74 in 70% yield with moderate α-selectivity (α/β = 2.2:1) (Scheme 10).127 Under similar conditions, 4C1-restricted fluorosugar 75 generated C-glycoside 76 in 85% yield with high α-selectivity (α/ β > 50:1), whereas 1C4-restricted fluorosugar 77 furnished β-C-

The trapping of glycosyl radicals generated from glycosyl halides with electron-deficient reagents has been demonstrated to be an effective approach to the synthesis of C-glycosides.49−53,65,66 Usually, the mild radical glycosylation results in the formation of α-C-glycosides. Thus, the conventional radical glycosylation of 2,3-trans-oxazolidinone-protected glycosyl bromide 90 with methyl acrylate in the presence of Bu3SnH/2,2′-azobisisobutyronitrile (AIBN) led to α-C-glycoside 91 in 74% yield with excellent α-selectivity (α/β > 99:1) (Scheme 13).138−142 Glucosyl bromide 1 was treated with vinyl sulfone 92 under the activation of Bu3SnH/AIBN to furnish α-C-glucoside 93 in 66% yield.143−145 Similarly, glucosaminyl α-chloride 26 was reacted with allyltrimethylstannane in the presence of AIBN to afford α-C-allyl glycoside 94 as the predominant product in 73% yield (α/β = 12:1).146,147 Treatment of L-fucosyl bromide 95 with olefin 96 initiated by Bu3SnH/Et3B/O2 gave α-C-fucoside 97 (61%).148 Photoinduced coupling of galactosyl bromide 98 with diethyl vinylphosphonate generated α-C-glycosyl ethylphosphonate 99 in good yield.149,150 Use of the Ni(II) salt and manganese dust as an initiator for the glycosylation of bromide 1 with methyl acrylate gave α-C-glucoside 100 (69%).151 Exposure of glucosyl bromide 1 to [CrII(EDTA)]2− complex (EDTA = ethylenediaminetetraacetic acid) followed by addition of methyl acrylate produced α-C-glucoside 101 in 76% yield.152 The similar reaction of 1 with electron-deficient alkenes utilizing [Cp2TiCl]2 (Cp = cyclopentadienyl) as a radical initiator also gave Cglucosides with good α-selectivity.153 The ethylpiperidinium hypophosphite- (EPHP-) mediated radical reaction of glucosyl iodide 102 with pentafluorophenyl acrylate afforded α-Cglucoside 103 stereoselectively in high yield.154 12288


Chemical Reviews

Review

Scheme 8. C-Glycosylation with Glycosyl Fluorides

Scheme 9. C-Glycosylation of Potassium Alkynyl Trifluoroborates with Glycosyl Fluorides

Scheme 10. C-Glycosylation with Conformationally Restricted and Unrestricted Xylosyl Fluorides

2.4. C-Glycosylation with Glycosyl Halides through Transition-Metal Complexes

Use of the transition-metal-mediated cross-coupling reactions, especially the name reactions, constitutes an alternative to the synthesis of C-glycosides.49−53,68,69 Substrates and catalysts serve as the two major parameters for transition-metal-mediated stereoselective C-glycosylations. As an example, Negishi crosscoupling of mannosyl bromides or chlorides with primary alkyl zinc reagents using NiCl2 as the catalyst and pyridine-linked bis(oxazoline) (PyBox) as the ligand gave C-mannosides 106− 108 in good yields with high α-selectivities (α/β = 8:1 to α only)

The continuous photoflow reaction of sugar bromides with acrolein in the presence of [Ru(dmb)3]2+ (dmb = 4,4′-dimethyl2,2′-bipyridine) resulted in the formation of α-C-glucosides 104 and 105 through the glucosyl radical intermediates in moderate yields (Scheme 14).155,156 12289


Chemical Reviews

Review

Scheme 11. Synthesis of a C-Analogue of the Bacterial Glycolipid BbGL2 with Galactosyl Iodide

Scheme 12. C-Glycosylation with Glycosyl Halides through Anionic Sugar Species

Scheme 13. C-Glycosylation with Glycosyl Halides through Glycosyl Radical Species

(Scheme 15).89 In contrast, similar couplings with glucosyl bromides or chlorides led to C-glucosides 109−111 in

satisfactory yields but with poor stereoselectivities (α/β = 1:1.1 to 1:2.5). 12290


Chemical Reviews

Review

Scheme 14. Ru-Catalyzed Continuous-Flow Synthesis of CGlycosides with Glycosyl Bromides

Scheme 17. C-Glycosylation of Activated Alkenes with Glycosyl Bromides

Scheme 15. C-Alkylation with Glycosyl Halides through Negishi Cross-Coupling

Scheme 18. C-Glycosylation of Alkyl Acids with Glycosyl Bromides and the Proposed Mechanism

Ni(COD)2-catalyzed Negishi cross-coupling of the glucosyl and galactosyl bromides with a variety of arylzinc reagents in the presence of 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine (tBuTerpy) was carried out to afford C-aryl glycosides 112−116 with the β-anomers as the predominant products (Scheme 16).157 A mixture of C-mannoside 117 (α/β = 2.9:1) was obtained when the mannosyl bromide was used for the coupling. Moreover, Ni-catalyzed reductive coupling of various glycosyl bromides with activated alkenes provided the corresponding αglycosides 118−123 in good yields (60−80%) (Scheme 17).158 Ni-catalyzed reductive coupling of sugar bromides with alkyl acids using zinc as the reductant furnished C-acyl glycosides 124−126 in excellent yields favoring the α-anomers (from α/β = 2.9:1 to α only) (Scheme 18).159 Preliminary mechanistic studies indicated that the coupling might be due to a radical chain mechanism (Scheme 18).159−163 Oxidative addition of the in situ Scheme 16. C-Arylation with Glycosyl Bromides through Negishi Cross-Coupling

12291


Chemical Reviews

Review

Scheme 19. Cobalt-Catalyzed C-Glycosylation of Grignard Reagents with Glycopyranosyl Bromides

Under the promotion of Co(acac)3 (acac = acetylacetonate), coupling of ether- and ester-protected furanosyl bromides with various Grignard reagents provided C-furanosides 133−138 and 140−142 in good yields and excellent 1,2-trans stereoselectivities (Scheme 20).166 When 2-deoxyfuranosyl chloride was employed, the coupling yielded C-furanoside 139 in poor diastereoselectivity (α/β = 1.3:1) because of the absence of the 2-substituent group.

3. C-GLYCOSYLATION WITH GLYCALS Glycals are one of the most widely used electrophilic cationic sugar species for constructing the anomeric CC bonds of Cglycosides.49−53 Usually, electrophilic C-glycosylation of glycals with C-nucleophiles takes place through Ferrier rearrangement through the oxonium ion (A) to provide 2,3-unsaturated Cglycosides, favoring the formation of α-anomers (Scheme 21a).167,168 2-Nitroglycals can react with C-nucleophiles through Michael addition to produce intermediate B, which leads favorably to β-C-glycosides (Scheme 21b).169 Transition-metaldirected cross couplings with glycals and their derivatives, such as the Heck, Suzuki−Miyaura, and Stille reactions, are another important strategy for accessing unsaturated C-glycosides.68,69,170 The coupling between glycals and the corresponding coupling partners under the promotion of palladium catalyst usually generates the addition complex (C) or the Pd π-allyl species (D), which undergoes reductive elimination or allylic coupling to provide 2,3-unsaturated C-glycosides (Scheme 21c). Palladium-catalyzed coupling of glycal derivatives such as iodoglycals, glycal pinacol boronates, and stannylated glycals with coupling partners proceeds through the formation of addition complex E, yielding C-glycals after the reductive elimination step (Scheme 21d). Occasionally, reactions of glycal anions (F), for example, lithiated glycals and glycosyl samariums derived from glycals, with C-electrophiles are employed to produce C-glycals (Scheme 21e).65,67,171,172 Furthermore,

generated acid anhydride to Ni0 gave complex A, which underwent oxidative addition with alkyl radical followed by reductive elimination, furnishing the product ketone and complex C. Reaction of complex C with alkyl halide afforded alkyl radical and complex D, where complex D could be reduced into the starting materials for another catalytic cycle. It was noted that complex C might be initially produced from the addition of halide derived from R−X to complex A, followed by reductive elimination of acyl halide. In addition, by optimizing the coupling conditions, aryl anhydrides could also be coupled with sugar bromides to provide C-aroyl glycosides.164 Cobalt-catalyzed cross-coupling of mannosyl and galactosyl bromides with a series of Grignard reagents afforded C-aryl and C-vinyl glycosides 127 and 129−132 with high α-selectivities (α/β > 9:1), whereas the coupling of the glucosyl bromide under similar conditions generated C-phenyl glucoside 128 with moderate α-selectivity (α/β = 3:1) (Scheme 19).165

Scheme 20. Cobalt-Catalyzed C-Glycosylation of Grignard Reagents with Glycofuranosyl Bromides and Chlorides

12292


Chemical Reviews

Review

Scheme 21. Plausible Mechanistic Schemes for C-Glycosylation with Glycals

Coupling of glucals 143−145 with allylsilane provided α-Callyl glycosides 151, 162, and 163, respectively, in good yields. Upon replacement of the allylsilane with silyl cyanide, the coupling furnished cyanide 156 with the α-anomer as the single product. In contrast, peracetyl pentose glycal 148 under similar conditions produced β-anti-C-glycoside 164 exclusively. Glycosylation of peracetyl glucal 143 with allylsilane, silyl cyanide, silyl enol ether, or silyl acetylene using zinc(II) triflate [Zn(OTf)2] as the catalyst afforded the desired C-glycosides (151, 156, 161, 165) in excellent yields with the α-anomers as the major products.185 When D-galactal 146 and D-xylal 148 were used, the zinc-mediated coupling resulted in 2,3-unsaturated glycosides (157, 164) with excellent α-selectivities. When the reaction was promoted by RuCl3, glycals 143, 145, and 146 reacted with various nucleophiles to provide the corresponding α-C-glycosides (151, 156, 157, 161, 162) in good yields with varied anomeric selectivities (from α/β = 60:40 to α only).186 Similarly, the AuCl3-catalyzed Ferrier reactions of glycals 143, 146, and 149 with allylsilane led to 2,3-unsaturated C-glycosides 151, 157, and 166 with the α-anomers as the major products.187 Trimethylsilyl triflate- (TMSOTf-) promoted glycosylation of galactal 3-O-trichloroacetimidate 150 with allylsilanes, propargylsilane, and silyl enol ethers furnished α-C-glycosides 167− 171 in excellent yields.188 Coupling of glucal 143 with difluoroenoxysilanes under the promotion of BF3·OEt2 afforded difluoro-C-glycosides 172−175 in satisfactory yields with the αanomers as the major products.199−201 Ferrier rearrangements of glycals with nonsilylated Cnucleophiles could also provide the 2,3-unsaturated C-glycosides

addition of in situ generated radicals to glycal derivatives can lead to 2-keto-α-C-glycosides.173 3.1. C-Glycosylation with Glycals through Glycosyl Electrophilic/Cationic Species

Reactions of glycals with silylated C-nucleophiles under the influence of various promoters provide 2,3-unsaturated sugars through Ferrier rearrangement with the α-anomers as the predominant products (Table 1).174−201 Thus, coupling of peracetylated glucal 143 with silylated nucleophiles such as allylsilane, propargylsilane, and silyl enol ether promoted by ytterbium(III) triflate [Yb(OTf)3] produced C-pseudoglycals 151−155 in good yields (88−94%) and excellent α-selectivities (from α/β = 5:1 to α only).174,175 In the presence of iodide, glycals 143 and 146 reacted with allylsilane and silyl cyanide to give 2,3-unsaturated glycosides 151 and 156−158 in high yields with the α-anomers as the major products.176,177 InCl3-catalyzed glycosylation of various glycals (143, 146, 147) with allylsilane and silyl cyanide under microwave conditions afforded α-C-allyl glycosides (151, 157, 159) as the predominant anomers and αC-cyanides (156, 158, 160) with moderate selectivities.178,179 Use of the bismuth(III), thulium(III), and gadolinium(III) triflates [Bi(OTf)3, Tm(OTf)3, and Gd(OTf)3, respectively] as the promoters for similar reactions provided the corresponding C-glycosides (151, 154, 156−158, 161) in good yields with high α-selectivities.180−182 Likewise, coupling using HClO4·SiO2 as the catalyst yielded the α-C-glycosides (151, 156, 162) as the major products (62−90%, α/β = 2:1−20:1).183 Ceric ammonium nitrate (CAN) was also found to be an effective reagent for promoting Ferrier rearrangement.184 12293


Chemical Reviews

Review

Table 1. Ferrier Rearrangements of Glycals with Silylated Nucleophiles

12294


Chemical Reviews

Review

Table 2. Ferrier Rearrangements of Glycals with Non-Silylated Nucleophiles

12295


Chemical Reviews

Review

Scheme 22. TMSOTf-Catalyzed Synthesis of β-(1 → 2)-C-Disaccharides with Glycals

Scheme 26. Michael Addition of Other C-Nucleophiles to 2Nitroglycals

Scheme 23. InBr3-Catalyzed Reaction of Phenyl Amine with Glycals

Scheme 24. Michael Addition of Dimethyl Malonate and Its Analogues to 2-Nitroglycals

Scheme 27. C-Glycosylation with Miscellaneous Glycals

Scheme 25. Michael Addition of Enamino Esters to 2Nitrogalactals

with α-selectivities (Table 2).202−225 Exposure of vinyl oxiranes 176 and 177 to organolithium reagents generated 1,4-cis-Cglycosides 182−185 in high yields with excellent anomeric selectivities.202,203 Yb(OTf)3-mediated glycosylation of glycals 12296


Chemical Reviews

Review

Scheme 28. C-Glycosylation with Glycals through Anionic Sugar Species

with excellent α-selectivities.213−215 Zinc-, copper-, and goldmediated reactions of unactivated alkynes with glycals 143, 145, 146, and 149 proceeded smoothly to provide α-C-alkynyl glycosides 165 and 195−199 in a highly stereoselective fashion.216−218 Under the catalysis of InCl3, coupling of glucal 143 with heteroaromatic compounds such as 2-benzyloxymethylfuran, thiophene, and N-tert-butoxycarbonyl- (N-Boc-) protected indole led to C-glycosides 200−202 in 68−90% yields with high β-selectivities.219 Decarboxylative glycosylation of glycals 143 and 146 with β-keto acids using FeCl3 as the catalyst provided β-keto-functionalized C-glycosides 154, 203, and 204 in 36−80% yields with varied anomeric selectivities (from α/β = 5:3 to α only).220,221 Reaction of 143 and 146 with unactivated aryl methyl ketones under the catalysis of tert-butyldimethylsilyl triflate (TBSOTf) in the presence of iPrNEt led to α-Cglycosides 154, 203, and 205 in moderate yields.222 SnCl4mediated coupling of glycals 143, 178, and 180 with titanium enolate derived from (S)-4-isopropyl-N-propanoyl-1,3-thiazolidine-2-thione afforded α-C-glycosides 206−208 as the predominant products in excellent yields (79−94%).223−225 The chiral auxiliary (R or S) determined the configuration of the newly formed stereocenters; switching the stereochemistry of the chiral auxiliary provided β-C-glycosides as the major anomers.223−225 Intriguingly, treatment of 3-deoxyglucal 209 with TMSOTf led to dimerization probably through the 3H4 half-chair conformer (A) of the glycal-derived oxocarbenium ion, affording β-(1 → 2)-C-glycoside 210 in 86% yield (Scheme 22).226 Similarly, TMSOTf-promoted dimerization of 3-deoxygalactal 211 produced β-(1 → 2)-C-glycoside 212 in excellent yield (88%).

Scheme 29. Coupling of Difluoromethyl Radicals with 2Benzyloxyglycals

143 and 147 with alkylaluminums gave C-glycosides 186−188 in good yields albeit in poor diastereoselectivities.204 Addition of organozinc reagents to glycals 178, 179, and 181 was reported to afford α-C-glycosides 189−191 in good yields.205,206 Treatment of glucal 143 with potassium alkynyltrifluoroborates using BF3· OEt2 as the promoter afforded alkynyl glycosides 165, 192 and 193 in 66−89% yields favoring the α-anomers (from α/β = 93:7 to α only).207,208 Indium-mediated Ferrier-type coupling of glycals 143 and 146 with 1-iodo-2-phenylacetylene was reported to give C-alkynyl glycosides 165, 194, and 195 with high αselectivities.209−212 TMSOTf-catalyzed glycosylation of glucal 143 and L-rhamnal 149 with unactivated alkynes provided alkynyl glycosides 165, 192, and 196 in moderate to good yields 12297


Chemical Reviews

Review

Scheme 30. C-Glycosylation with Furanoid Glycals by Heck Cross-Coupling

Scheme 33. C-Glycosylation with Glycals by Oxidative Heck Cross-Coupling and the Proposed Mechanism

Scheme 31. C-Glycosylation with Pyranoid Glycals by Heck Cross-Coupling

Scheme 32. C-Glycosylation of Phenylboronic Acid with Glucal 143

InBr3-catalyzed reaction of glucal 143 with phenyl amine led to the formation of 1-C,3-N-bicyclic compound 213 in 85% yield as the only diastereomer (Scheme 23).227 However, reaction of Dxylal 148 with phenyl amine under similar conditions followed by treatment with ammonia yielded a mixture of diastereomers 214 and 215 with poor selectivity [66%, diastereomeric ratio (dr) = 1:1]. 2-Nitroglycals and congeners have been utilized for the construction of 2-substituted C-glycosides.169,229−237 Michael addition of dimethyl malonate and its analogues to 2-nitrogalactal in the presence of t-BuOK produced β-C-glycosides 216−219 in good yields (Scheme 24).229 However, it gave a mixture of C-glycoside 220 (92%, β/α = 2:1) when 2-nitroglucal was used in the reaction. C-Glycosylation of 2-nitrogalactal with enamino esters based on Michael-type addition under solvent-free conditions resulted in the formation of β-C-glycosides 221−223 in excellent yields (Scheme 25).230

Furthermore, 2-nitrogalactal 224 reacted with vinylmagnesium bromide to give a mixture of C-glycoside 225 (61%), whereas Michael addition of chiral bicyclic compound 226 to 224 generated α-C-glycoside 227 in a stereocontrolled manner 12298


Chemical Reviews

Review

Scheme 34. C-Diarylation with Glycals by Domino Heck− Suzuki Cross-Coupling

Scheme 36. C-Glycosylation of Aryl Hydrazines with Glycals by Oxidative Heck Cross-Coupling

(Scheme 26).231,232 Similarly, nitro-Michael addition of phenyllithium to 2-nitroglucal 228 afforded β-C-glucoside 229 in 71% yield.233 Treatment of 228 with sulfur ylide 230 in the presence of 1-phenylthiourea proceeded through a hydrogen-bondstabilized nitronate intermediate followed by a [4 + 1]

cycloaddition and rearrangement, providing isoxazoline 231 in 80% yield with 91% diastereomeric excess (de).234

Scheme 35. Dual-Catalyzed C-Glycosylation of (o-Azaaryl)carboxaldehydes with Glycals and a Proposed Mechanism

12299


Chemical Reviews

Review

Coupling of 2-acetoxy-D-glucal 232 with mesitylene 233 using hydrogen fluoride pyridine as the promoter or with allyltrimethylsilane using HClO4·SiO2 as the promoter afforded enones 234 and 235 in good yields with the α-anomers as the major products (Scheme 27).235,236 Michael addition of Ph2CuLi to glucal-derived enone 236 followed by treatment with acetic anhydride furnished enol acetate 237 in 60% yield with good αselectivity (α/β = 88:12).237

Scheme 37. Palladium-Catalyzed Decarboxylative and Desulfitative C-Glycosylation with Glucal

3.2. C-Glycosylation with Glycals through Glycosyl Anionic Species

Umpolung of glycals by lithium or samarium reagents serves as a means for nucleophilic attack on C-electrophiles to provide Cglycal derivatives.65,67 For instance, coupling of lithiated glycal 238 with α-ketol 239 afforded cis-diol 240 in 75% yield as the only diastereoisomer (Scheme 28).39 Addition of lithiated derivative of rhamnal 241 to quinone 242 followed by quenching with water resulted in a mixture of quinol glycal 243 and quinone glycal 244 in almost equal amounts.238,239 Lithiated species derived from 2-chloroglycal 245 was added to the carbonyl group of hexacarbonyl chromium, providing α,β-unsaturated carbine complex 246 in 66% yield after ethylation.240−242 Thermalpromoted cyclization of 246 with a series of alkynes yielded the quinones or hydroquinones 247 in low to moderate yields. Treatment of cyclohexanone 249 with the corresponding samarium enolate species (A) generated from SmI2-induced polar inversion of the sialyl-derived allylic benzoate 248 furnished exclusively 2,3-unsaturated α-C-glycoside 250 in 97% yield.243

Scheme 38. C-Glycosylation through Pd(II)-Catalyzed Decarboxylative Alkylation of Glycals

3.3. C-Glycosylation with Glycals through Radical Species

Apart from the reaction of anomeric radicals,244,245 addition of radicals to glycals can also provide C-glycosides. For example, Et3B-initiated coupling of •CF2CO2Et radical with 2-benzyloxyglucal 251 proceeded smoothly to give 2-keto-α-CF2-glycoside 252 as the major product (55%, α/β = 3:1) (Scheme 29).173,246 When galactal 253 was used, the radical reactions with BrCF2CO2Et and Br2CF2 furnished 2-keto-α-CF2-glycosides 254 and 255, respectively, as the sole products.

Scheme 39. Palladium-Catalyzed Decarboxylative Allylation/ Wittig Reaction with Glucal 288

3.4. C-Glycosylation with Glycals through Transition-Metal Complexes

Scheme 40. Rh(I)-Catalyzed C-Glycosylation of Boronic Acids with Glycal-Derived Enones

Transition-metal-mediated cross-coupling reactions of glycals, iodoglycals, glycal pinacol boronates, and stannylated glycals were employed for the construction of C-glycosides of various skeletons.49−53,68,69 Pd-catalyzed Heck cross-coupling of furanoid glycals with aryl halides or triflates led to 2,3-unsaturated βC-aryl glycosides 256−260 in good yields (Scheme 30).247−254 Through control of the reaction parameters, the Pd-catalyzed Heck coupling of pyranoid glycals with aryl or vinyl halides produced the α-C-aryl or α-C-vinyl glycosides 261−263 in high yields (Scheme 31).255−257 These reactions usually involve oxidative addition of halides followed by insertion of olefins and β-H elimination, providing 2,3-unsaturated pseudoglycals as the desired products.255,256 C-Glycosylation of peracetylated glucal 143 with phenylboronic acid under the catalysis of palladium(II) acetate [Pd(OAc)2] afforded α-C-phenyl glycoside 264 as the only anomer in 80% yield (Scheme 32).258 Pd(OAc)2-mediated oxidative Heck coupling of glucal 265 with phenylboronic acid in the presence of benzoquinone (BQ), 2,3-dichloro-5,6-dicyano-pbenzoquinone (DDQ), or Cu(OAc)2/O2 gave rise to the ketone, enone, or enol ether types, respectively, of C-glycosides 266− 268 in high yields (Scheme 33).259 As shown in Scheme 33, the

Scheme 41. Ni-Catalyzed C-Glycosylation of Grignard Reagent with Pseudoglucal 294

12300


Chemical Reviews

Review

Scheme 42. Pd-Catalyzed C-Glycosylation of Alkene and Alkyne with Iodoglycal 296

Scheme 43. Synthesis of C-Glycosides with Iodoglycal through the Pd- or Pd/Cu-Catalyzed CH Activation

yields, probably because of the steric hindrance between the bulky palladium species and the C-3 protecting group (Scheme 36).262 However, when (3S)-glucal 277 was employed, a mixture of C-glycoside 279 (α/β = 1:1) was formed, indicating that the stereochemistry of C-3 is not the only factor in the α-selectivity. It should be noted that Pd(OAc)2-catalyzed decarboxylative Heck cross-coupling of glucal 143 with 2,6-dimethoxybenzoic acid 280 under the assistance of Ag2CO3 and PPh3 in a mixture of dimethyl sulfoxide (DMSO) and DMF at 80 °C gave 2-deoxy-αC-aryl glycoside 281 in 79% yield, whereas PdCl2-catalyzed desulfitative Ferrier-type C-glycosylation of glucal 143 with sodium p-chlorobenzenesulfinate 282 in the presence of CuCl2 and LiCl in acetonitrile at 75 °C produced α-C-aryl glycoside 283 in 74% yield (Scheme 37).263,264 Moreover, Pd-catalyzed coupling of glycals with other classes of coupling partners such as trimethylsilyl cyanide, diethyl malonate, and silylated acetylide, also provided C-glycosides.265−267 Use of Pd(II)-catalyzed decarboxylative allylation reaction for the C-glycosylation of 3,5-cis glycal 284 with the ketone enolate anion resulting from ionization provided β-C-glycoside 285 in 90% yield through the Pd π-allyl species (Scheme 38).268 In contrast, coupling of 3,5-trans glycal 286 under similar conditions generated a mixture of C-glycoside 287, probably because the formations of the Pd π-allyl species from the α and β faces of 286 are close in energy (91%, α/β = 1.2:1). Recently,

normal Heck coupling proceeded to give the enol ether-type product (cycle I). However, when BQ or DDQ was employed as the oxidant, the combination of the enol ether-type product with Pd(OAc)2 led to the palladium complexes (A and B), which underwent hydrolysis (cycle II) or β-H elimination (cycle III) to provide the ketone or enone product. When 1 equiv of glycal was treated with 2 equiv of arylboronic acid in the presence of Pd(OAc)2 and 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) in acetic acid, 1,2-(α,α)-diarylated-Cglycosdies 269−272 were obtained in good yields through a domino Heck−Suzuki cross-coupling (Scheme 34).260 The dual catalyzed C-glycosylation of glycals with (o-azaaryl)carboxaldehydes was reported to provide C-glycosides 273− 276 in 75−85% yields (Scheme 35).261 The reaction involved the union of π-allyl Pd complex generated from glycal with the Breslow intermediate generated from N-heterocyclic carbenecatalyzed umpolung of aldehyde, resulting in intermediate A. Intramolecular nucleophilic addition of the N-heterocycliccarbene- (NHC-) activated aldehyde moiety to the allylic system followed by regeneration of the NHC catalyst led to intermediate C, which underwent proton transfer under basic conditions to furnish the ketone product. Pd(OAc)2-catalyzed oxidative Heck cross-coupling of (3R)glucal 143 with aryl hydrazines underwent CN bond cleavage, affording exclusively α-C-glycosides 264 and 278 in excellent 12301


Chemical Reviews

Review

Scheme 44. Synthesis of C-Glycosides by Suzuki−Miyaura Cross-Coupling with Glycal Derivatives

Scheme 45. Synthesis of Aryl Vinyl Ether by Suzuki−Miyaura Cross-Coupling with Cyclic Ketene Acetal Phosphate 314

Scheme 46. C-Glycosylation with 1-Stannylglycals by Stille Cross-Coupling

Rh(I)-catalyzed C-glycosylation of glycal-derived enones with boronic acids was developed for the synthesis of α-C-glycosides 291−293 in good yields (Scheme 40).270 Additionally, Nicatalyzed coupling of p-tert-butylphenyl 4,6-di-O-TBS-2,3dideoxy-α-D-erythro-hex-2-enopyranoside 294 with 4-chlorophe-

Pd(II)-catalyzed one-pot decarboxylative allylation/Wittig reaction using glucal 288, P-ylide 289, and paraformaldehyde as substrates and 1,4-bis(diphenylphosphino)butane (DPPB) as the ligand was reported to afford C-vinyl glycoside 290 in 92% yield with excellent β-selectivities (Scheme 39).269 12302


Chemical Reviews

Review

Scheme 47. C-Glycosylation with 1-Stannylglycal by Desulfitative or Carbonylative Stille Cross-Coupling

Scheme 48. Transition-Metal-Mediated C-Glycosylation with Other Glycal Derivatives

nylmagnesium bromide was reported to give β-C-aryl glycoside 295 in 60% yield (Scheme 41).271 Use of Pd(Ph3P)2Cl2 as the catalyst for the coupling of iodoglycal 296 with sugar-substituted cycloadduct 297 gave a dihydronaphthol intermediate, which was oxidized in situ to provide C-aryl glycoside 298 in 68% yield (Scheme 42).272 Furthermore, Pd-catalyzed Sonogashira−Hagihara coupling of iodoglycal 296 with alkynyl glycoside 299 afforded pseudodisaccharide 300 in almost quantitative yield.273,274 Iodoglycals were also utilized for the synthesis of C(hetero)aryl glycosides through Pd- or Pd/Cu-catalyzed CH activation. Pd(OAc)2-catalyzed CH functionalization of Nquinolyl benzamide 301 with iodoglucal 296 in the presence of Lproline derivative L produced C-aryl glycoside 302 in 83% yield probably through a palladacycle intermediate (A) (Scheme 43).275 Recently, CH activation of five-membered nitrogen heterocycles such as indoles, thiazoles, imidazoles, and benzoxazoles with iodoglycals under the cocatalysis of Pd-

(OAc)2/CuI was reported.276 As an example, C-glycosylation of N-tosylindole 303 with iodoglucal 296 in the presence of 1,10phenanthroline furnished C-heteroaryl glycoside 304 in 81% yield (Scheme 43). Suzuki−Miyaura cross-coupling of iodoglycal 296 with alkyl borane derived from 305 under the catalysis of [1,1′bis(diphenylphosphino)ferrocene]dichloropalladium(II) [Pd(dppf)Cl2] provided C-glycoside 306 in 88% yield (Scheme 44).277 Glycal pinacol boronate 307 was coupled with sterically hindered aryl bromide 308 under Suzuki−Miyaura coupling conditions to give product 309 (88%).31,278 Moreover, 307 could be coupled with sugar iodides 310 and 312 using appropriate sp2−sp3 Suzuki−Miyaura coupling conditions to furnish (1 → 6)- and (1 → 2)-pseudo-C-disaccharides 311 and 313 in good yields.279 Suzuki−Miyaura coupling of cyclic ketene acetal phosphate 314 with 3-nitrophenylboronic acid 315 in the presence of Pd(PPh3)4 gave aryl vinyl ether 316 in 88% yield (Scheme 45).280 12303


Chemical Reviews

Review

Stille cross-coupling of stannylated glycal 317 with αiodostyrene under the aid of Pd(PPh3)4/CuI/CsF produced diene 318 (66%) (Scheme 46).281 Treatment of 1-stannylglycal 319 with aryl bromide 320 under Stille coupling conditions proceeded rapidly to yield pseudo-C-aryl glycoside 321 (80%).282−284 Under the standard Stille coupling conditions, 1stannylglycal 322 was coupled with exocyclic bromoolefin 323 to furnish (1 → 2)-pseudo-C-disaccharide 324 in 60% yield.285 Under similar conditions, (1 → 3)- and (1 → 4)-pseudo-Cdisaccharides were efficiently synthesized.285 It is worth noting that desulfitative Stille cross-coupling of stannylated glucal 325 with naphthalene-1-sulfonyl chloride 326 provided the corresponding pseudo-C-aryl glycoside 327 in 58% yield, whereas carbonylative Stille cross-coupling of 325 with iodoglucal 328 under 50 bar CO atmosphere furnished dienone 329 in 81% yield (Scheme 47).286,287 Palladium-catalyzed Negishi-type cross-coupling of in situ generated zincated glucal 330 with 4-iodophenylalanine derivative 331 gave C-aryl glycoside 332 in 69% yield (Scheme 48).288,289 Coupling of glucal silanol 333 with aryl iodide 334

Scheme 49. C-Cyanation with Glycosyl Acetates

Scheme 50. C-Allylation with Glycosyl Acetates

12304


Chemical Reviews

Review

Scheme 51. Stereochemcial Models for the Formation of β-C-Lyxopyranoside 353 and α-C-Ribopyranoside 354

Scheme 52. Stereochemical Models for the Formation of the C-Furanosides

Scheme 54. Nucleophilic Reaction of Thioalkyl-Substituted Tetrahydropyran Acetate 366

under the catalysis of Pd2(dba)3·CHCl3 (dba = dibenzylideneacetone) provided C-aryl glycoside 335 (82%).32,290 The Pdcatalyzed reaction of pseudoglucal 336 with methyl azlactone 337 gave access to α-C-glycoside 338 in high yield.291 Additionally, treatment of tris(dihydropyranyl)indium 339 with aryl bromide 340 in the presence of PdCl2(PPh3)2 provided substituted dihydropyran 341 in 72% yield.292

C-glycoside rearrangement. Notably, sialyl acetate could be converted to organosamarium species in the presence of SmI2 for nucleophilic C-glycosylation.294 4.1. C-Glycosylation with Glycosyl Acetates through Glycosyl Electrophilic/Cationic Species

Treatment of glycosyl acetates 342 and 344 with trimethylsilyl cyanide (TMSCN) and BF3·OEt2 afforded β-cyanides 343 and 345 in good yields (Scheme 49).90,295−297 Lactone 346 reacted with TMSCN under the promotion of Sc(OTf)3 to give 2-Cbranched β-cyanide 347 in 90% yield.298,299 Other Lewis acids such as Zn(OTf)2 under similar conditions also provided βcyanides in good yields.300 Coupling of glycopyranosyl acetates with allyltrimethylsilane or bromoallylsilane in the presence of BF3·OEt2 or SnBr4 provided α-C-glycosides 348, 349, and 351 as the predominant glycosides (α/β > 20:1) and α-C-glycosides 350 and 352 as the major products (α/β > 2:1) (Scheme 50).29,301−309 BF3·OEt2-

4. C-GLYCOSYLATION WITH GLYCOSYL ACETATES Glycosyl acetates have been utilized for the synthesis of Cglycosides since more than 50 years ago.293 The stereoselectivities for electrophilic C-glycosylation of glycosyl acetates generally comply with rules similar to those found in Cglycosylation with glycosyl halides (Scheme 1a). Among them, electrophilic C-arylation of glycosyl acetates, in particular, 2deoxy-glycosyl acetates, usually leads to β-C-glycosides, no matter whether it involves a normal C-glycosylation or an O- →

Scheme 53. C-Glycosylation of Fused-Bicyclic 2-Deoxyfuranosyl Acetate 364

12305


Chemical Reviews

Review

Scheme 55. Solvent Effects in the Nucleophilic Reaction of Tetrahydropyran Acetate

Scheme 56. Nucleophilicities and Selectivities in C-Glycosylation of 2-Deoxyglucosyl Acetate

Scheme 59. Indium-Catalyzed C-Alkynylation with Glycosyl Acetates

Scheme 57. TMSOTf-Catalyzed C-Alkynylation Reactions with Glycosyl Acetates

Scheme 58. C-Glycosylation of Organozinc Reagent with Glycosyl Acetate 379 through a Pyridinium Salt Intermediate

12306


Chemical Reviews

Review

Scheme 60. Synthesis of Difluoro C-Glycosides with Glycosyl Acetates

(A), providing 1,3-cis product 365 in 86% yield with >95:5 selectivity (Scheme 53).314 The nucleophilic substitution reaction of 4-CH2SEt-substituted acetate 366 with allyltrimethylsilane provided 1,4-cis product 367 as the major diastereomer, indicating that neighboring group participation was not responsible for the product formation (Scheme 54).315 The reaction might conform to the Curtin−Hammett principle, in which the major 1,4-cis product was formed through the overall lower-energy pathway from the 4-equatorially substituted oxocarbenium ion 3H4 conformer (A), but not from the lowerenergy sulfonium ion intermediate (C). Recently, solvents were found to determine the selectivity of nucleophilic substitution reactions between tetrahydropyran acetate 369 and silyl ketene acetals 370 in the presence of TMSOTf (Scheme 55).316−318 In polar solvents such as EtCN, the formation of 1,4-trans product 371 was favored (1,4-cis/1,4trans = 17:83), possibly by means of an SN1 mechanism through the solvent-separated ion pair (A). In contrast, nonpolar solvents such as Cl2CCHCl revealed high selectivity for the SN2-like reaction through the contact ion pair (B) or the axial triflate (C), leading to 1,4-cis product 372 as the predominant diastereomer (1,4-cis/1,4-trans = 91:9). TMSOTf-activated C-glycosylation of 2-deoxyglucosyl acetate 373 with weak nucleophile allyltrimethylsilane preferred to undergo SN1 reaction through attack on the stereoelectronically favored face of the 4H3 conformer (B) of the solvent-separated oxocarbenium, in accord with Curtin−Hammett kinetics, despite the fact that 4H3 conformer B is higher in energy than 3H4 conformer A, providing α-C-glycoside 374 as the major product (57%, α/β = 89:11) (Scheme 56).319 When a strong nucleophile such as silyl ketene acetal 375 was employed, similar coupling afforded β-C-glycoside 376 as the major product (68%, α/β = 19:81) by means of the SN2-like pathway through the glycosyl triflate C or the associated contact ion pair. These results demonstrate that the nucleophile reactivity can exert a significant influence on the stereoselectivity of C-glycosylation reactions. TMSOTf-catalyzed alkynylation of glycosyl acetates with tributylstannyl(trimethylsilyl)acetylene produced α-linked Cglycosides 377 in 65−90% yields and α-linked 2-azido-Cglycosides 378 in 35−64% yields (Scheme 57).320−323 Coupling of perbenzyl 2-deoxyglucosyl acetate 379 with Ph2Zn under the assistance of TMSOTf and 2-methoxypyridine proceeded through the pyridinium-type salt intermediate (A), leading to α-C-glycoside 380 in 92% yield with excellent α-selectivity (α/β > 95:5) (Scheme 58).324 Indium-mediated coupling of glycosyl acetates with 1-iodo-2phenylacetylene or 1-iodo-2-(trimethylsilyl)acetylene provided C-alkynyl glycosides 57, 381, and 382 with varied stereoselectivities depending on the substrate structure (Scheme 59).125 2-Deoxypyranosyl acetate 383 was coupled with difluoroenoxysilane 384 in the presence of SnCl4 to give α-difluoro-Cpyranoside 385 in 49% yield (α/β = 93:7), whereas 2-

promoted C-allylation of lyxopyranosyl acetate gave C-glycoside 353 in 64% yield with high β-selectivity (α/β = 8:92), whereas the similar C-allylation of ribopyranosyl acetate produced Cglycoside 354 in 63% yield with excellent α-selectivity (α/β = 91:9).310 The β-product 353 might arise from the nucleophilic attack on the oxocarbenium ion through the preferred 3H4 conformer B, whereas the α-product 354 was formed by nucleophilic attack on the oxocarbenium ion through the favored 4 H3 conformer C (Scheme 51). Reaction of furanosyl acetates with allylsilane promoted by BF3·OEt2 or ZnBr2 led to α-Cglycoside 355 or β-C-glycoside 356, respectively, as the major product.311−313 SnBr4-mediated coupling of 3-O-benzyl-2deoxyribosyl acetates with allylsilane produced C-glycoside 357, 358, and 360 with high 1,3-cis selectivity, which was not strongly influenced by the stereochemistry at C-4.126 Replacing the 3-benzyloxy group with a 3-methyl group reversed the stereoselectivity to generate 1,3-trans glycoside 359 as the predominant anomer. The 1,3-cis selectivity (e.g., 362) was high when the 2-O-benzyl group was cis to the 3-O-benzyl group. However, lower 1,3-cis selectivities were observed (e.g., 361, 363) when the 2,3-trans di-O-benzyl groups were installed on the sugar moiety. The formation of 1,3-cis products 357, 358, 360, and 362 as the major products can be explained by the stereoelectronically preferred inside attack on the lower-energy conformer (A) (Scheme 52a).126 However, the 3-methylsubstituted oxocarbenium ion developed a syn-pentane interaction upon nucleophilic attack to the C-3 axial conformer; thus, the nucleophilic reaction prefers to attack the C-3 equatorial counterpart, providing 1,3-trans glycoside 359 as the major product. Although the C-3 alkoxy substituent adopting a pseudoaxial orientation exerts a significant influence on the above 1,3-cis selectivities, switching the stereochemistry at C-2 to the 2,3-trans oxocarbenium ion would involve the unfavorable pseudoaxial orientation of the C-2 alkoxy group on the conformer C, leading to lower selectivities for 361 and 363 (Scheme 52b).126 The reaction of bicyclic acetate 364 bearing a disiloxane ring with allyltrimethylsilane promoted by BF3·OEt2 proceeded through the inside attack on the low-energy diaxial conformer

Scheme 61. Synthesis of C-Siloxymethyl Glycoside with Glycosyl Acetate 388

12307


Chemical Reviews

Review

Scheme 62. C-Arylation with Glycosyl Acetates

SnCl4/AgOTf resulted in a mixture of C-aryl glycoside 397 with poor stereoselectivity (67%, α/β = 1:1).334 As an example of TMSOTf-catalyzed Friedel−Crafts-type C-glycosylation, the reaction of glycosyl acetate 398 with tricycle 399 provided βC-8-linked glycoside 400 in 82% yield.335−337 Reaction of 2-deoxyglycosyl acetate 401 with furan provided C-glycoside 402 in 74% yield with the β-anomer as the major product (α/β = 1:9) (Scheme 63).272,338 Glycosylation of a mixture of acetate 403 with furan in the presence of BF3·OEt2 furnished β-C-furyl glycoside 404 in 78% yield as a mixture of diastereomers at C-3 (dr = 72:28).339,340 Lewis-acid-promoted O- → C-glycoside rearrangements involving the initial formation of O-glycoside intermediates (A) followed by Fries-like O → C rearrangements were utilized effectively for the synthesis of C-aryl glycosides (Scheme 64).41−43,335,336,341−360 As an example, Sc(OTf)3-promoted glycosylation of 2-deoxyglycosyl acetates with substituted phenols provided complex β-C-aryl glycosides 405−407 in excellent yields.41,335,341 Upon use of SnCl4 as the activator, complex C-aryl glycosides 408 and 409 were obtained in good yields as the β-anomers.43,334 Under the conditions of Cp2HfCl2/ AgClO4, similar reactions led to β-C-aryl glycosides 410 and 411 as single regio- and diastereoisomers in moderate yields.346,347 Additionally, the glycosylation of glycosyl acetate with naphthol

Scheme 63. C-Glycosylation of Furan with Glycosyl Acetates

deoxyfuranosyl acetate 386 under similar conditions afforded αdifluoro-C-furanoside 387 in 76% yield (α/β > 95:5) (Scheme 60).199,325 Treatment of cellobiose peracetate 388 with HSiMe2Et/CO/Co2(CO)8 produced β-C-siloxymethyl disaccharide 389 in 66% yield as the only anomer (Scheme 61).326,327 Arylation of glucopyranosyl acetate 390 with 1,4-dimethoxynaphthalene promoted by SnCl4/AgOTf gave access to β-Cglucoside 391 in 60% yield (Scheme 62).328−330 BF3·OEt2promoted intramolecular Friedel−Crafts-type C-aryl glycosylation of 392 afforded 1,2-cis thiochroman 393 in 92% yield.331,332 HF-mediated intramolecular Friedel−Crafts-type C-arylation of 2-aminoglucosyl acetate 394 proceeded smoothly to give 1,2-cis C-aryl glycoside 395 in 88% yield.333 However, treatment of disaccharide acetate 396 with 4-methylanisole in the presence of 12308


Chemical Reviews

Review

Scheme 64. C-Arylation with Glycosyl Acetates through the O- → C-Glycoside Rearrangement

Scheme 65. C-Glycosylation of Ketone with Glycosyl Acetate and the Postulated Mechanism for the Formation of Glycosyl Samarium(III) Species

in the presence of BF3·OEt2 proceeded smoothly to give β-C-aryl glycosides 412 in 73% yield.348

anomeric radical B produced organosamarium species C, which could be rearranged to samarium enolate D.

4.2. C-Glycosylation with Glycosyl Acetates through Glycosyl Anionic Species

5. C-GLYCOSYLATION WITH 1,2-ANHYDRO SUGARS Ring opening of 1,2-anhydro sugars for C-glycoside synthesis often relies on the recruitment of organometallic C-nucleophiles, where the selectivity can be explained by an SN1/SN2 mechanism analogous to the C-glycosylation of glycosyl halides depicted in Scheme 1.361,362 Coupling of 1,2-anhydro sugars with organolithium and Grignard reagents leads to C-glycosides with varied stereoselectivities depending on the substrates and conditions. Organoaluminum (borane), organozinc, and organozirconocene prefer to induce cis-opening of 1,2-anhydro sugars, providing 1,2-

Glycosyl acetates are occasionally used as substrates for generation of anionic species, which could be trapped by Celectrophiles for C-glycosylation. As an example, reductive samariation of sialyl acetate 413 led to a glycosyl samarium(III) species, which was reacted with cyclic ketone 414 to provide αsialoside 415 in 85% yield (Scheme 65).294 The reaction proceeded through two single electron transfer process, in which a chelate structure A might be vital for the first single electron transfer to give anomeric radical B. Further reduction of the 12309


Chemical Reviews

Review

Scheme 66. C-Glycosylation of Lithiated Indoles with 1,2-Anhydromannose 416

Scheme 67. C-Glycosylation of Organocuprate and Organolithium with 1,2-Anhydroglucose 423

Scheme 69. C-Glycosylation of Aluminum or Borane Reagents with 1,2-Anhydro Sugar

Scheme 68. C-Glycosylation of Grignard Reagents with 1,2Anhydro Sugar

Scheme 70. C-Glycosylation of Dialkyl and Diaryl Zinc Reagents with 1,2-Anhydro Sugar

5.1. C-Glycosylation with 1,2-Anhydro Sugars through Glycosyl Electrophilic/Cationic Species

Treatment of 1,2-anhydromannose 416 with C-2 lithiated indole derivatives 417 in the presence of BF3·OEt2 provided a mixture of C-glycosides 418−422 in moderate yields (Scheme 66).365 When sulfonamide was used as the N-protecting group, αselectivities were observed for 418, 420, and 422. Conversely, when Boc was used as the N-protecting group, β-anomers 419 and 421 were isolated as the major products.

cis-C-glycosides, whereas reactions of organocuprates with 1,2anhydro sugars favor the formation of 1,2-trans-C-glycosides. It is noteworthy that 1,2-anhydro sugars can also undergo radical reactions with C-electrophiles under the initiation of SmI2 or Cp2TiCl2/Mn to give C-glycosides stereoselectively.363,364 12310


Chemical Reviews

Review

Scheme 71. C-Glycosylation of in Situ Aryl Zinc Bromide Species with 1,2-Anhydro Sugars

Scheme 73. C-Glycosylation of in Situ Alkenylzirconocenes with 1,2-Anhydro Sugars

the reaction temperature was a key factor in modulating the stereoselectivity. To achieve α-selectivity in the synthesis of C-glycosides, epoxide 423 was treated with organoaluminums to give the set of α-C-glucosides 433−437 in high yields (76−85%) with excellent stereoselectivities through syn transfer of the nucleophile to the oxocarbenium ion intermediate (Scheme 69).366,376,377 Nevertheless, reaction of triallyl aluminum with 423 generated a mixture of α/β anomers 438 (α/β = 2.3:1). Replacement of triallyl aluminum with triallyl borane allowed the selectivity to be significantly improved (α/β = 13:1). Remarkably, treatment of epoxide 423 with dialkyl and diaryl zinc reagents assisted by CF3COOH provided C-glycosides 433, 436, and 437 in good yields with the α-anomers as the sole products (Scheme 70).378 Addition of in situ generated aryl zinc bromide species to epoxides was also demonstrated to be an effective method for αselective C-glycosylation, affording the series of α-C-aryl glycosides 439−444 in moderate to good yields with high diastereoselectivities through the syn opening pathway (Scheme 71).379−381 Furthermore, coupling of 1,2-anhydro sugars with aryl zinc reagents generated in situ from the reaction of phenylboronic acid and diethyl zinc was carried out to furnish a range of α-Cglycosides (436 and 445−449) as the only anomers, probably through intramolecular syn attack on the anomeric carbon of oxocarbenium ion A (Scheme 72).382 AgClO4-catalyzed C-glycosylation of 1,2-anhydro sugars with alkenylzirconocenes prepared from hydrozirconation of terminal alkynes provided another approach for 1,2-cis-C-glycosylation, resulting in C-glycosides 450−453 in good yields (67−76%) with excellent α-selectivities (Scheme 73).383

Scheme 72. C-Glycosylation of in Situ Aryl Zinc Reagents with 1,2-Anhydro Sugars

Coupling of 423 with lithium dimethyl(diphenyl)cuprates produced β-C-glucosides 424 and 425 in high yields as the only anomers (Scheme 67).366 In contrast, coupling with silylated ethynyl lithium led to C-ethynyl glucoside 426 in 80% yield with complete α-selectivity.366 Exposure of 1,2-anhydroglucose 423 to Grignard reagents (e.g., propenyl magnesium chloride, propargyl magnesium chloride, and vinyl magnesium bromide) gave exclusively β-Cglucosides 427−429 in good yields (Scheme 68).366−375 However, other Grignard reagents (e.g., butenyl magnesium chloride, acetal magnesium chloride, and phenyl magnesium chloride) under similar conditions afforded a mixture of α- and βC-glucosides 430−432 (α/β = 1:1).366,370,371 It was found that

5.2. C-Glycosylation with 1,2-Anhydro Sugars through Glycosyl Radical Species

1,2-Anhydro sugars can be activated by metal reagents to produce anomeric radicals for C-glycosylation. For instance, SmI2-promoted reductive coupling of α-glycosyl epoxides with isobutyraldehyde in the presence of NiI2 gave α-C-glycosides 454 and 455 exclusively through the anomeric radical A, whereas similar reactions with acetone afforded β-C-glycosides 456 and 457 as the major isomers (Scheme 74).363 In terms of β-epoxide 12311


Chemical Reviews

Review

Scheme 74. SmI2-Promoted Radical C-Glycosylation with 1,2-Anhydro Sugars

Scheme 75. Cp2TiCl2-Promoted Radical C-Glycosylation with 1,2-Anhydro Sugars

Scheme 76. C-Glycosylation of Silylated Nucleophiles with Thiopyranosides and the Associated Stereochemical Model

12312


Chemical Reviews

Review

Scheme 77. C-Glycosylation of Silylated Nucleophiles with 2,3-Anhydrothiofuranoside 472

Scheme 80. C-Allylation with Glycosyl Sulfoxides

Scheme 78. Intramolecular C-Glycosylation with Thioglycoside 475 Bearing a 9-Anthracenylmethyl Group at C-2-OH

Scheme 81. C-Allylation with Sulfone 486

6. C-GLYCOSYLATION WITH THIOGLYCOSIDES, SULFOXIDES, AND SULFONES In comparison to the wide use of thioglycosides in Oglycosylation,385 thioglycosides have found limited application in C-glycosylation.49−53,147,386,387 Similarly to the reaction pathways of C-glycosylation for glycosyl halides (Scheme 1), the electrophilic C-glycosylation of thioglycosides, sulfoxides, and sulfones can afford C-glycosides stereoselectively; however, the outcomes are highly dependent on the glycosyl substrates, Cnucleophiles, and reaction conditions. On the other hand, umpolung of thioglycosides, sulfoxides, and sulfones by lithium reagents or SmI2 can give rise to glycosyl anionic apecies;49−53,65,67,388−391 nucleophilic attack of C-electrophiles on the resulting glycosyl anionic species provides C-glycosides. It is noted that C-sialylation of thioglycosides and sulfones tends to produce α-C-sialosides in a stereoselective fashion.

sugars, couplings with both aldehydes and ketones under similar conditions stereoselectively yielded α-C-glycosides. In addition, ring opening of α-epoxide sugars using Cp2TiCl2 and manganese dust followed by trapping of the anomeric radical (A) with alkenes enabled the synthesis of a series of α-Cglycosides (458−462) in good yields (Scheme 75).364,384 Scheme 79. C-Alkylation with Thiosialoside 478

12313


Chemical Reviews

Review

Scheme 82. C-Glycosylation with Thioglycoside, Sulfoxide, and Sulfone through Glycosyl Anionic Species

6.1. C-Glycosylation with Thioglycosides, Sulfoxides, and Sulfones through Glycosyl Electrophilic/Cationic Species

79).398 However, the analogous coupling with weak nucleophile allyltrimethylsilane yielded a mixture of C-sialoside 482 in 50% yield (α/β = 1:1.2). Nonetheless, with the more nucleophilic methyl-substituted allylsilane as the acceptor, the yield and stereoselectivity for the synthesis of 483 were significantly improved (80%, α only). These results reveal that C-sialylation with strong nucleophiles usually leads to C-sialosides in high yields with excellent α-selectivities. C-Glycosylation of glycosyl sulfoxides with allyltrimethylsilane in the presence of Tf2O and 2,6-di-tert-butyl-4-methylpyridine (DTBMP) gave α-C-allyl glycosides 348, 484, and 485 as the predominant anomers (α/β > 19:1) in 75−90% yields (Scheme 80).399 However, preactivation of glycosyl sulfoxides with Tf2O and DTBMP followed by addition of allyltributylstannane led to the corresponding C-allyl glycosides with poor β-selectivity. Sulfones are rarely utilizied for electrophilic C-glycosylation.400 The BF3·OEt2-promoted reaction of furanosyl sulfone 486 with allyltrimethylsilane afforded C-allyl glycoside 487 in 85% yield as the only diastereomer (Scheme 81).401

Glycosylation of 4,6-O-benzylidene-protected thiomannosides with allylsilane and silyl enol ether activated by 1-benzenesulfinyl piperidine (BSP)/Ph2SO and triflic anhydride (Tf2O) in the presence of 2,4,6-tri-tert-butylpyrimidine (TTBP) gave the corresponding β-C-glycosides 463−466 as the only or major anomers (β/α > 5:1) (Scheme 76).392−394 Similar α/β selectivities were observed for the coupling with allylstannane.392−394 However, the corresponding thioglucosides led to α-C-glycosides 467−470 in moderate yields. The observed stereoselectivities for C-glycosylation with 4,6-O-benzylideneprotected thiomannosides and thioglucosides can be explained by the nucleophilic attack on the preferred conformers (B2,5 A for 4,6-O-benzylidene-protected thiomannosides; 4H3 B for 4,6-Obenzylidene-protected thioglucosides) of the oxocarbenium ion intermediates from the opposite face of the C-2−H-2 bond. The glycosylation of perbenzyl thiomannoside with allylsilane led to C-allyl mannoside 471 with poor stereoselectivity (α/β = 2:1) because of the conformation change of the corresponding oxocarbenium ion intermediate. Glycosylation of 2,3-anhydrothiofuranoside 472 with allylsilane and silyl enol ether activated by BF3·OEt2 induced stereocontrolled migration of the thiotolyl group from C-1 to C-2, providing β-linked C-glycosides 473 and 474 in high yields (Scheme 77).395 Similarly, 2,3-anhydro-1-thiopyranosides were reacted with silylated or stannylated C-nucleophiles under the promotion of Lewis acids such as TMSOTf and Sc(OTf)3 to provide 1,2-trans C-glycosides in moderate to good yields.396 Unexpectedly, reaction of 2-(9-anthracenylmethyl) thioglycoside 475 with alcohols using dimethyl(methylthio)sulfonium triflate (DMTST) as the promoter resulted in the stereoselective formation of glycosides 476 and 477 in good yields through intramolecular participation of the anthracenylmethyl group (Scheme 78).397 C-Sialylation of N-acetyl-5-N,4-O-oxazolidinone-protected thiosialoside 478 with silyl enol ethers and silyl ketene acetal under the promotion of (p-Tol)2SO and Tf2O provided exclusively α-C-sialosides 479−481 in high yields (Scheme

6.2. C-Glycosylation with Thioglycosides, Sulfoxides, and Sulfones through Glycosyl Anionic Species

C-Sialylation of thioglycoside 488 with aldehyde 489 promoted by SmI2 gave α-C-linked disaccharide 490 in 93% yield (Scheme 82).402 β-D-Glucosyl sulfoxide 491 was subjected to phenylsulfinyl lithium exchange to generate glycosyl lithium, which was reacted with isobutyraldehyde to give β-C-glycoside 492 in 50% yield with retention of the anomeric configuration.403,404 The promoter system SmI2/NiI2 has been reported to promote the Cglycosylation of glucosyl 2-pyridyl sulfone 493 with tert-butyl acrylate 494, providing α-C-glycoside 495 in good yield (80%).405 In addition, treatment of thioglycoside with lithium 4,4′-di-tert-butylbiphenylide (LiDBB) gave rise to glycosyl lithium, which was added to carbonyl compounds to afford the corresponding C-glycosides in good yields but with poor diastereoselectivities.406 SmI2-mediated C-glycosylation of phenyl or 2-pyridyl sulfones with carbonyl compounds was proved to be an effective method to construct C-glycosides (Scheme 83).407−422 The reaction proceeded through successive single electron transfer to produce 12314


Chemical Reviews

Review

Scheme 83. SmI2-Mediated C-Glycosylation of Carbonyl Compounds with Glycosyl Sulfones

with alkenes and alkynes, affording C-glycosides by a radical pathway, as described in Scheme 1c.65,66,423−425 Stereoselective cyclization of unrestricted phenyl selenoglucoside 508 bearing a phenylethynylsilyl group at the 6-hydroxy group under the classical radical conditions and subsequent removal of the silyl group afforded β-C-glucoside 509 in 54% yield, probably through a conformationally 1C4-flipped intermediate (A) (Scheme 84).426−430 Although the radical cyclization of unrestricted selenoglucoside 510 containing the 2-O-allylsilyl group led to a mixture of C-glucoside 511 (80%, α/β = 1:4.1), the cyclization of conformationally 1C4-restricted selenoglucoside 512 bearing the 2-O-allylsilyl group provided α-C-glucoside 513 exclusively in 99% yield. Likewise, the reaction with the conformationally 1C4restricted selenoglucoside 514 bearing the 6-O-allylsilyl group furnished β-C-glucoside 515 as the only product in 72% yield.

anomeric organosamarium B, which could attack the carbonyl compounds to provide the C-glycosides stereoselectively. As such, a series of 1,2-trans C-furanosides and C-pyranosides 496− 499 were obtained in moderate to good yields.408−411 When the 2-acetamido glucosyl sulfone was used, product 500 was isolated as a 1:1 anomeric mixture.412,413 Employing NiI2 as cocatalyst, the SmI2-induced glycosylation produced 1,2-trans glycosides 501 and 502 in high yields.414 Condensation of sialyl sulfones with aldehydes or ketones in the presence of SmI2 afforded α-Cglycosides 503 and 504 and α-C-linked disaccharides 505−507 in moderate to good yields.415−422

7. C-GLYCOSYLATION WITH SELENOGLYCOSIDES AND TELLUROGLYCOSIDES For C-glycosylation, selenoglycosides and telluroglycosides are mainly employed in intra- or intermolecular radical reactions 12315


Chemical Reviews

Review

Scheme 84. Intramolecular Radical C-Glycosylation with Conformationally Restricted and Unrestricted Selenoglucosides

Scheme 86. Intramolecular Radical C-Glycosylation with Selenoribosides Bearing Propargyl Moieties

Scheme 87. Radical C-Glycosylation with 2-Acetamido Glycosyl Selenides

Scheme 88. Radical C-Glycosylation with 2-Acetamido-1Methylglycosyl Selenides Scheme 85. Radical C-Glycosylation with Conformationally Restricted Selenoxylosides

Scheme 89. Radical C-Glycosylation with Galactosyl Telluride 537

cyclic diketal 517 with Bu3SnCH2CHCH2 followed by cleavage of the protecting groups and subsequent benzoylation gave xyloside 520 in good yields and high α-stereoselectivities (69−73%, α/β = 85:15−91:9) (Scheme 85).431−434 Conversely, allylation of 1C4-restricted 2,4-O-cyclic phenylboronate 518 and

Based on the conformational restriction strategy, the radical allylation of 4C1-restricted 2,3-O-cyclic diketal 516 and 3,4-O12316


Chemical Reviews

Review

Scheme 90. C-Glycosylation with Sugar Lactols under Mitsunobu Conditions

2,3,4-tris-O-triisopropysilyl (2,3,4-tri-O-TIPS) ether 519 under similar conditions afforded xyloside 520 with the β-anomer as the predominant product (26−61%, α/β = 1:99). Upon replacement of the radical acceptor with CH2CHCN, a similar radical reaction with 519 provided β-cyanoethylated glycoside 521 exclusively in 66% yield. Additionally, intramolecular radical cyclization of phenyl selenoribosides 522 and 523 bearing propargyl moieties at the 5-hydroxy group provided β-C-ribosides 524 and 525 in high yields (Scheme 86).435 Exposure of 2-acetamide glycosyl selenides to radical conditions afforded anomeric radicals, which were trapped by various alkenes to provide α-C-glycosides 526−533 in a stereoselective manner (17−93%) (Scheme 87).436,437 Moreover, 2-acetamide-1-methylglycosyl selenides were reacted with various alkenes under the activation of Bu3SnH/AIBN to produce 1,1-disubstituted C-glycosides 534−536 in 29−79% yields, depending on the reactivity of the alkenes (Scheme 88).438 Coupling of galactosyl telluride 537 with quinone 538 under photothermal conditions gave α-C-glycosides 539 in moderate yield (Scheme 89).439

8. C-GLYCOSYLATION WITH SUGAR LACTOLS Sugar lactols can react through the Mitsunobu reaction, the Wittig reaction or Horner−Wadsworth−Emmons (HWE) olefination/Michael addition, or acid-mediated C-glycosylation with C-nucleophiles to provide C-glycosides.49−53,440,441 Coupling of pyranosyl lactols with C-nucleophiles was usually found to give 1,2-trans C-glycosides, whereas C-glycosylation with furanosyl lactols often led to a mixture of anomers. Remarkably, reaction of unprotected sugar lactols with C-nucleophiles could also afford C-glycosides in a simple and direct manner.442−445 Coupling of 2,3,4,6-tetra-O-benzyl-D-glucopyranose 540 with nucleophiles 541, 543, and 545 under Mitsunobu conditions [diethyl azodicarboxylate (DEAD) or 1,1′-(azodicarbonyl)dipiperidine (ADDP), n-Bu3P, PhH] furnished β-C-glucosides 542, 544, and 546 in 39−84% yields by means of an SN2 mechanism through the α-phosphonium intermediate (A) (Scheme 90).446 Treatment of lactol 547 with Wittig reagent PPh3CHCO2Et gave a mixture of C-glycoside 548 in 85% yield, whereas exposure of 5,6-ene-6-nitro-D-glucofuranose 549 to PPh3CHCO2Et resulted in the formation of α-C-vinyl glycoside 550 in 75% yield through Wittig olefination and subsequent oxy-Michael addition (Scheme 91).447,448 Horner−Wadsworth−Emmons olefination of diisopropylidene mannofuranose 551 with glucose-derived phosphonate 552 followed by intramolecular oxy-Michael addition afforded sulfone 553 in 85% yield (α/β = 1:1).449−452 For the preparation of phosphono analogues of natural glycosyl phosphates, a one-step Horner−Emmons/ Michael reaction involving coupling of monoisopropylideneprotected mannose derivative 554 with tetramethyl methylenediphosphonate 555 using t-BuOK as the base was employed

Scheme 91. C-Glycosylation with Sugar Lactols through Wittig or HWE Olefination/Michael Addition

Scheme 92. C-Glycosylation with Sugar Lactol through an Intramolecular Hetero-Michael Addition

12317


Chemical Reviews

Review

Scheme 93. Acid-Mediated C-Glycosylation with Sugar Lactols

to provide α-D-mannosyl methanephosphonate 556 as the predominant product (85%, α/β = 10:1).453 Interestingly, dehydrobromination of bromohydrin 557 by exposure to K2CO3/MeOH gave an E-olefinic cyclic lactonate (A) and its equilibrium intermediate of acyclic E-olefinic aldehyde (B), which then proceeded through an intramolecular hetero-Michael addition and ester hydrolysis to produce spirocyclic lactol 558 in excellent yield (Scheme 92).454 C-Glycosylation of lactol 559 with 1,3,5-trimethoxybenzene 560 employing dodecylbenzenesulfonic acid (DBSA) as the catalyst in water afforded C-nucleoside 561 in 62% yield with excellent β-selectivity (α/β < 1:20) (Scheme 93).455 Treatment of hemiacetal 562 with allyltrimethylsilane using InCl3 and Me3SiCl as an enhanced Lewis acid system gave C-allyl riboside 563 in moderate yield with good selectivity (α/β = 17:83).456−458 AuCl3-catalyzed C-glycosylation of lactol 540 with allylsilane provided α-C-glucoside 348 as the predominant anomer in 72% yield.459 When preactivated by trifluoroacetic anhydride (TFAA), arylation of lactol 540 with 1,3-diarylpropane 564 in the presence of BF3·OEt2 yielded β-C-glycoside 565 in 92% yield.33 Direct use of unprotected sugar lactols for coupling with Cnucleophiles represents an attractive approach en route to Cglycosides.442−445 Henry condensation of glucose 566 with nitromethane under the catalysis of sodium methoxide followed by reflux in water to promote dehydration and cyclization afforded β-C-glucoside 567 in 53% yield (Scheme 94).460−465 Coupling of glucose 566 with pentane-2,4-dione 568 in the presence of sodium bicarbonate proceeded through Knoevenagel reaction and intramolecular Michael cyclization to give β-Cglucoside 569 in excellent yield.442,466,467 Reactions of other types of unprotected sugar lactols such as 2-acetamido sugars, heptoses, xylose, and galactose with C-nucleophiles such as 1,3dicarbonyl compounds and 1,3-oxazine-2-thiones in the presence of base (NaHCO3, Na2CO3, NaH, or KOH) or Lewis

acid (InCl3, CoCl2) also afforded the corresponding C-pyranoor C-furanoglycosides in good yields with high β-stereoselectivities.14,468−483 As an example of Sc(OTf)3-promoted Cglycosylation of unprotected sugar lactols with aryl compounds, direct glycosylation of glucose 566 with 570 gave β-C-aryl glycoside 571 (65%).484−489 Horner−Wadsworth−Emmons reaction of lactose 572 with β-ketophosphonate 573 under basic conditions provided β-C-glucoside 574 (67%).490,491 Aldol reaction of D-deoxyribose 575 with acetoacetic ester 576 catalyzed by iPr2NEt and 2-pyridone led to hemiketal 577 with high diastereoselectivity (45%, dr > 49:1).492 Under the promotion of L-proline and DBU, the Knoevenagel−Michael cascade reaction of D-ribose 578 with dimethyl 3-oxoglutarate 579 gave C-glycoside 580 (86%, dr > 49:1), whereas the aldolMichael reaction of 578 with acetone 581 provided a mixture of α- and β-C-glycosides 582 and 583 and the hemiketal 584 in a 69% overall yield.493−495 Other amine-mediated aldol-Michael reactions of unprotected ketoses or 2-N-acyl-aldohexoses with acetone 581 have also been reported for the synthesis of Cglycosides.496,497 Recently, Cu(I)-catalyzed dehydrative Cglycosylation of unprotected 2-deoxy sugar 585 with acetophenone 586 in the presence of diphosphine ligand L1 was reported to give C-glycoside 587 in quantitative yield with excellent βselectivity (β/α > 20:1).498 As an example of the synthesis of Cglycosides between unprotected aldoses and amines through Amadori rearrangement, D-glycero-D-gulo-heptose 588 was reacted with benzyl amine 589 in a mixture of acetic acid and ethanol to produce α-C-glucoside 590 in high yield (95%).499−502

9. C-GLYCOSYLATION WITH SUGAR LACTONES Sugar lactones have found wide applications for C-glycosylation since the 1900s.503,504 Sugar lactones can react with Cnucleophiles to give hemiketals, which are usually reduced by silane and Lewis acid through hydride attack on the α-face of the 12318


Chemical Reviews

Review

Scheme 94. Synthesis of C-Glycosides with Unprotected Sugar Lactols

Scheme 95. Plausible Mechanistic Scheme for C-Glycosylation with Sugar Lactones

12319


Chemical Reviews

Review

furnished C-arabinoside 600 in moderate yield with the αanomer as the major product.542,543 In addition, lactol formation by reaction of lactone 601 with lithiated furan and subsequent hydride reduction with NaBH3CN provided β-C-glycoside 602, whereas addition of lithiated pyrimidine to ribonolactone 603 followed by the standard reduction and removal of t-butyl groups produced 1,2trans glycoside 604 as a single anomer (Scheme 99).272,507,544−548 Exposure of mannono-1,5-lactone 605 to lithiated difluoromethyl-2-pyridyl sulfone 606 in the presence of hexamethylphosphoramide (HMPA) afforded C-glycoside 607 in 73% yield.549 Condensation of galactonolactone 608 with lithiated dithiinyl reagent 609 followed by treatment with Et3SiH and BF3·OEt2 provided C-vinyl glycoside 610 with complete βselectivity.550,551 Addition of sugar lactones with Grignard reagents followed by reduction of the resulting hemiketals gave rise to C-glycosides 611−613 in high yields favoring the formation of the β-anomers (Scheme 100).9,306,552−562 Addition of trimethylaluminum to gluconolactone 614 led to hemiketal 615 in 89% yield (Scheme 101).563 Zinc-mediated Reformatsky addition of ethyl bromodifluoroacetate to lactone 605 generated fluorinated C-mannoside 616 in 70% yield, whereas the indium-mediated Reformatsky reaction of mannosederived lactone 617 with α-bromolactone 618 under sonication conditions preferentially gave α-anomer 619 in 53% yield.564,565 Cobalt-mediated addition of α-bromoester to lactone 608 resulted in β-hydroxyl ester 620 in 91% yield.566,567 In addition, reaction of diethyl iodomethylphosphonate with mannonolactone 605 employing SmI2 as the promoter afforded βketophosphonate 621 as the only anomer in 70% yield.568 Reaction of perbenzylated lactone with a range of lithiated nucleophiles afforded lactols, which were then treated with (CF3CO)2O under dehydration conditions to provide conjugated exo-glycals 622−624 in good yields (Scheme 102).569−572 Wittig reaction of sugar lactones with tributylphosphorane ylids gave rise to (Z)-exo-glycals 625−627 in high yields (Scheme 103).573,574 The modified Julia olefination of sugar lactones with benzothiazol-2-yl sulfones in the presence of lithium bis(trimethylsilyl)amide (LHMDS) followed by elimination of the sulfonic acid on hemiketals with DBU afforded exo-glycals 628−630 in good yields (Scheme 104).575−579 Not surprisingly, methylenation of a range of sugar lactones with Petasis reagent [Cp 2 Ti(CH 3) 2 ] or Tebbe reagent [Cp2TiCH2ClAl(CH3)2] proceeded smoothly to afford exocyclic enol ethers 631−635 in 65−81% yields (Scheme 105).255,580−585

Scheme 96. C-Glycosylation of Lithium Enolate or Aryl Lithium with Sugar Lactones

oxocarbenium ion intermediate (A) because of the kinetic anomeric effect, affording β-C-glycopyranosides as the major products without acetoxy group participation (Scheme 95).505,506 The β-selectivity could be further improved by fixing the conformation of the sugar substrates in the 4C1 chair form by a 3,4-O-cyclic diketal or a 4,6-O-benzylidene protecting group.506 As for ketofuranoses, Lewis-acid-mediated reduction using silane as the reductant preferentially gave 1,2-trans C-furanosides through hydride attack cis to the 2-subsituent.507 On the other hand, the adducts can serve as substrates to produce exo-glycals that represent a class of molecules bearing exo-CC double bonds at the anomeric position. Nucleophilic addition of lithium enolate or aryl lithium to sugar lactones followed by reduction using silane and BF3·OEt2 afforded the corresponding C-glycosides 591−594 in good yields with complete β-selectivity (Scheme 96).11,34,505,508−525 Introduction of ethynyl groups onto sugar lactones involved nucleophilic addition with lithium (trimethylsilyl)acetylide in the presence of CeCl3 and deoxygenation with Et3SiH and BF3· OEt2; subsequent desilylation with aqueous NaOH led to βalkynyl glycosides 595−597 in good yields (Scheme 97).526−537 Reaction of galactonolactone with 2-lithiobenzothiazole, acetylation of the resulting lactol, and subsequent reduction using Et3SiH and TMSOTf provided exclusively β-C-galactoside 598 in 69% yield, which is a precursor to the formyl C-glycoside (Scheme 98).538,539 When the galactonolactone was replaced by gluconolactone, similar reactions gave a mixture of C-glucoside 599 in a moderate 55% yield with poor stereoselectivity (β/α = 3:2).540,541 It is worth noting that the reaction of 2-lithiothiazole with D-arabinolactone followed by acetylation using acetic anhydride and deoxygenation using SmI2 and ethylene glycol

Scheme 97. C-Glycosylation of Lithium (Trimethylsilyl)acetylide with Sugar Lactones

12320


Chemical Reviews

Review

Scheme 98. C-Glycosylation of 2-Lithiothiazole and Its Derivatives with Sugar Lactones

Scheme 99. C-Glycosylation of Other Lithiated Reagents with Sugar Lactones

Scheme 100. C-Glycosylation of Grignard Reagents with Sugar Lactones

10. C-GLYCOSYLATION WITH GLYCOSYL IMIDATES AND PHOSPHATES Despite their wide application for the synthesis of O-glycosides, glycosyl imidates and phosphates are less frequently utilized for C-glycoside synthesis, which can proceed through the oxocarbenium ion intermediates analogous to C-glycosylation of glycosyl halides (Scheme 1a).49−53,586−588 As an example, 2azido glucosyl trichloroacetimidate 636 was treated with TMSCN under the promotion of TMSOTf to give α-C-cyanide 637 in high yield (Scheme 106).589 Glycosylation of acetonide-

protected D-ribosyl trichloroacetimidate 638 with pyrrole derivative in the presence of BF3·OEt2 afforded 3-C-glycoside 639 in 61% yield with the α-anomer as the major product (α/β = 2:1).27 Upon use of peracetylated glucosyl trichloroacetimidate 640 as the donor, coupling with dipyrromethane proceeded in a regio- and stereoselective fashion to provide β-C-glucoside 641 in 91% yield.590 For the synthesis of 1,3-diglycosylindoles, mannosyl trichloroacetimidate was coupled with N-glycosyl indoles to furnish α-Cglycosides 642 and 643 in moderate yields as the only anomers 12321


Chemical Reviews

Review

Scheme 101. Other Metal-Mediated C-Glycosylations with Sugar Lactones

Scheme 103. Synthesis of exo-Glycals with Sugar Lactones through the Wittig Reaction

(Scheme 107).321 With D-fucosyl trichloroacetimidate as the donor, the resulting 1,3-diglycosylindoles 644 and 645 were synthesized in a β-selective fashion. Intramolecular Sakurai cyclization of 4,6-O-benzylideneprotected mannosyl trichloroacetimidate 646 using TMSOTf as the catalyst with the assistance of TTBP at −20 °C resulted in cis-fused C-mannoside derivative 647 (70%) and trans-fused Cmannoside derivative 648 (25%) (Scheme 108).591 The formation of the cis- and trans-fused C-mannoside derivatives can be explained by the equilibrium between the mannosyl triflate A and conformers B (4H3) and C (B2,5) of the mannosyl oxocarbenium ion transition state, in which the B2,5 conformer C can be attacked by the pendant allylsilane moiety from both faces of the oxocarbenium ion. Similar intramolecular Sakurai cyclization of 4,6-O-benzylidene-protected glucosyl trichloroacetimidate 649 produced only cis-fused C-glucoside derivative 650 in 92% yield (Scheme 108). In this reaction, the 4H3 and B2,5 conformers (E and F, respectively) of the oxocarbenium ion

allowed for only α-face nucleophilic attack, providing cis-fused Cglucoside derivative 650 as the only product. Based on a cation clock method utilizing the present intramolecular Sakurai cyclization, a low concentration dependence was observed for the C-glycosylation of methallyltrimethylsilane with both the mannose and glucose series, indicating that the reactions proceed through an SN1-like mechanism. It is noteworthy that switching the trichloroacetimidate group of 646 to the corresponding sulfoxide under the promotion of Tf2O and TTBP could also lead to both cis- and trans-fused C-mannoside derivatives by a similar mechanism.591,592 Generally, C-arylation of glycopyranosyl imidates favors the fomation of 1,2-trans-C-glycosides irrespective of the 2-Oprotecting groups. Coupling of glucosyl trichloroacetimidates 651 and 640 with phenols 652 and 654 underwent the O- → Cglycoside rearrangements to produce β-C-aryl glucosides 653 and 655 in good yields (Scheme 109).36,593−597 Glycosylation of perbenzylglucosyl N-phenyl trifluoroacetimidate 656 with tricycle 657 under the action of TMSOTf resulted in 4-β-C-glucoside 658 (43%) and 2-β-C-glucoside 659 (12%), which could be further elaborated into isomangiferin and mangiferin, respectively (Scheme 110).35 When glycosyl N-phenyl trifluoroacetimidates 656 and 662 were employed for coupling with phenols 660 and 663, the O- → C-glycoside rearrangements occurred to provide β-C-aryl glucoside 661 and α-C-aryl mannoside 664, respectively, in good yields (Scheme 111).587 Glycosylation of mannosyl and glucosyl phosphates with allylsilane under the activation of TMSOTf afforded α-C-allyl glycosides 485 and 348 in satisfactory yields (Scheme 112).598,599 When silyl enol ether was employed as the nucleophile, a similar coupling resulted in C-glycosides 665 and 666 in good yields as a mixture of diastereomers. It is noteworthy that TMSOTf-promoted C-glycosylation of mannosyl phosphate bearing a 2,6-lactone moiety with allylsilane furnished β-C-mannoside 667 in almost quantitative yield with excellent stereoselectivity (β/α > 99:1).600

Scheme 102. Synthesis of exo-Glycals with Sugar Lactones by Nucleophilic Addition of Organolithium Reagents

12322


Chemical Reviews

Review

Scheme 104. Synthesis of exo-Glycals with Sugar Lactones through Modified Julia Olefination

Scheme 105. Synthesis of exo-Glycals with Sugar Lactones by the Use of Petasis or Tebbe Reagent

affording C-cyanides and C-allyl glycosides with moderate stereoselectivities.602 Glycosylation of glucosyl and mannosyl phosphates 672 and 675 with phenols 673 and 676 in the presence of TMSOTf proceeded through the O- → C-glycoside rearrangement to afford β-C-aryl glucoside 674 and α-C-aryl mannoside 677, respectively, in good yields (Scheme 114).598,603

11. C-GLYCOSYLATION WITH 1-O-METHYL SUGARS 1-O-Methyl sugars require strongly acidic conditions for effective electrophilic C-glycosylation with C-nucleophiles through the oxocarbenium ion similarly to the C-glycosylation of glycosyl halides (Scheme 1a).49−53,604 Thus, allylation of a range of methyl glycosides with allyltrimethylsilane under the promotion of BF3·OEt2 or TMSOTf provided α-C-allyl glycosides 678−683 as the sole or predominant products in moderate to good yields (58−85%) (Scheme 115).302,605−616 TMSOTf-promoted coupling of methyl glucosides with allylsilane and propagylsilane under the assistance of ultrasonic radiation resulted in the series of α-allyl-C-glycosides 348, 684, and 685 and α-allenyl-C-glycosides 686−688 in high yields (Scheme 116).133,617 Treatment of methyl galactoside 689 with acetyloxyallylsilane followed by NaOMe generated α-C-galactoside 690 in 67% yield (Scheme 117).618 Reaction of galactofuranoside 691 with silyl enol ether gave phenone 692 in a satisfactory 61% yield.619,620 In the presence of SnCl4/AgOTf, reaction of methyl glucoside 693 with 1,4-dimethoxynaphthalene proceeded smoothly to afford β-C-aryl glucoside 694 in 76% yield (Scheme 118).328 Furthermore, BF3·OEt2-promoted glycosylation of 2-deoxyglycoside 695 with naphthol was carried out to yield β-C-aryl glucoside 696 in 60% yield.621−624 C-Glycosylation of methyl 2deoxy-riboside 697 with 2-bromofuran under the optimized conditions, namely, BF3·OEt2 as the promoter in a very short time (5 min), produced a mixture of C-glycoside 698 in 63% yield (α/β = 1:2.5).625 Additionally, intramolecular Friedel− Crafts cyclization of 2-deoxyglycoside 699 induced by aqueous HBF4 provided C-glycoside 700, albeit in low yield (13%).626,627

Scheme 106. C-Glycosylation with Glycosyl Trichloroacetimidates

TMSOTf-promoted C-sialylation of N-acetyl-5-N,4-O-oxazolidinone-protected sialyl phosphate 668 with various silyl enol ethers provided the corresponding C-sialosides (479, 480, 669, and 670) in high yields with excellent α-selectivities (from α/β = 82:18 to α only) (Scheme 113).601 However, the coupling of 668 with allylsilane in the presence of TMSOTf generated Cglycoside 671 with poor stereoselectivity (75%, α/β = 1:1). Upon switching allylsilane to the more nucleophilic allyltributylstannane, glycoside 671 was obtained in high yield with the αanomer as the only product (81%). It should be noted that glycosyl propane-1,3-diyl phosphates could also be used to react with TMSCN and allylsilane in the presence of TMSOTf,

12. SYNTHESIS OF C-GLYCOSIDES THROUGH REARRANGEMENT OF SUGAR PRECURSORS Construction of anomeric CC bonds through structural rearrangements of prerearranged sugar substrates, for example, Claisen rearrangement, Ramberg−Bäcklund rearrangement, and Wittig rearrangement, is considered to be an attractive approach for the preparation of C-glycosides.49−53,628−633 In most cases, the reactions proceed in a concerted manner to give C-glycosides with retention of the configuration at the anomeric centers. 12323


Chemical Reviews

Review

Scheme 107. C-Glycosylation of N-Glycosyl Indoles with Glycosyl Trichloroacetimidates

and DBU) afforded C-glycosides 724−727 in satisfactory yields (60−95%) with varied stereoselectivities (Scheme 123).660−665 Promoter systems, namely, Hg(OAc)2/I2, Pd(PPh3)4, and PhSeCl/AgOTf, were also utilized to promote the cyclization of δ-hydroxy alkenes, yielding C-glycosides 728−730 whose stereoselectivities were mainly controlled by the substrates and promoters.570,666−671 Furthermore, anodic coupling of δhydroxy olefin in methanol provided a mixture of C-glycoside 731 bearing a masked aldehyde in 70% yield.672−674 Cyclization of a series of γ-hydroxy alkenes in the presence of PhSeCl, NIS, Sc(OTf)3, PPh3·HBr, VO(acac)2/TBHP, Pd(OAc) 2 /NaOAc/O 2 , or OsO 4 /NMO followed by KIO 4 produced the corresponding cyclized products 732−737 in good yields (58−93%) (Scheme 124).675−683 Oxidation of γhydroxy alkenes to γ-hydroxy epoxides using meta-chloroperoxybenzoic acid (mCPBA)/camphorsulfonic acid (CSA) or tBuOOK as oxidant usually led to a mixture of C-glycosides with varied stereoselectivity.670,684−686 Treatment of diols with PPh3/diisopropyl azodicarboxylate (DIAD), POCl 3 , TsCl, Yb(OTf) 3 , [PPh 3 Au]TFA, or Co2(CO)8/TfOH/Et3N/I2 afforded C-glycosides 738−743 in 74−91% yields (Scheme 125).687−692 Careful selection of the substrates and the cyclization conditions could lead to stereoselective formation of C-glycosides. Base-promoted intramolecular nucleophilic displacement of 744 led to dihydropyran 745 in moderate yield as a mixture of diastereoisomers (Scheme 126).693,694 Oxidation of 746 with Ag2O led to the formation of o-quinone methide, which was attacked by the secondary hydroxyl group to provide exclusively C-aryl glycoside 747 in an excellent 94% yield.695 Rh(II)catalyzed cyclization of δ-hydroxydiazo compound 748 resulted in a mixture of C-glycoside 749 (65%, α/β = 1:3).696 Au(III)catalyzed cyclization of δ-hydroxy alkyne 750 proceeded smoothly to afford exo-glucal 751 in 82% yield.663 Oxidation of 752 with VO(acac)2/t-BuOOH followed by acetalization afforded dipyranone 753 in 86% yield.697,698 Reaction of γhydroxy alkene 754 with 1-bromo-4-tert-butylbenzene under the catalysis of Pd2(dba)3 provided substituted tetrahydrofuran 755 in 72% yield (dr > 20:1).699 InBr3-catalyzed reaction of δ-

Thus, thermal rearrangement of 2-vinyloxymethyl glucal 701 at 180 °C followed by reduction of the resulting aldehyde with NaBH4 gave C-glycoside 702 (81%, α/β = 66:34) (Scheme 119).634 Enol ether 703 was subjected to Claisen rearrangement, providing β-C-glycoside 704 in 84% yield.635−639 Disaccharide derivative 705 underwent thermal Claisen rearrangement to provide α-(1 → 6)-pseudo-C-disaccharide 706 in 83% yield.640 Application of Claisen rearrangement to ester 707 using LiHMDS and TMSCl followed by esterification of the newly forming acid with CH2N2 led to diastereoisomers 708 (73%) and 709 (12%) (Scheme 120).641,642 Treatment of disaccharide 710 with LiHMDS and TMSCl proceeded through the Ireland− Claisen rearrangement from the α-face of the anomeric center (C2′) to give the chairlike transition state A after formation of the (Z)-silyl enolate; subsequent exposure of A to (trimethylsilyl)diazomethane furnished α-CF2-sialoside 711 in 86% yield over two steps.643,644 The Ramberg−Bäcklund rearrangement of glycosyl sulfones using KOH/Al2O3 in CBr2F2, CBrF2CBrF2, or CCl4 provided exo-glycals such as 712−715 in moderate to good yields, with the Z isomers in most cases as the major products (Scheme 121).6,645−650 The 1,2-Wittig rearrangement of 716 in the presence of nBuLi gave β-C-glycoside 717 with high stereoselectivity, and the 1,4Wittig rearrangement of 718 in the presence of nBuLi afforded βC-glycoside 719 as the predominant anomer (Scheme 122).651 TMSOTf-promoted anomeric O → C rearrangement of enol ether 720 selectively produced cis-methyl product 721 in 86% yield.652−655 Similarly, treatment of vinyl ether 722 with TMSOTf provided β-C-glycoside 723 with excellent stereoselectivity.656

13. SYNTHESIS OF C-GLYCOSIDES WITH ACYCLIC SUBSTRATES Intra- or intermolecular cyclization of acyclic substrates, including SN2 nucleophilic reactions and cycloaddition reactions, is a complementary means for the synthesis of C-glycosides.47,49−53,657−659 Oxa-Michael cyclization of δ-hydroxy alkenes in the presence of a base (e.g., tBuOK, K2CO3, NaH, 12324


Chemical Reviews

Review

Scheme 108. Synthesis of C-Glycosides through Intramolecular Sakurai Cyclization of 4,6-O-Benzylidene-Protected Mannosyl and Glucosyl Trichloroacetimidates and Plausible Reaction Mechanisms

yield.720 Exposure of δ-triethylsilyl aryl ketone 765 to BiBr3 and Et 3 SiH followed by removal of the silyl group with tetrabutylammonium fluoride (TBAF) afforded 2,6-cis-substituted tetrahydropyran 766 in 93% yield with excellent diastereoselectivity.721,722 A tandem reaction involving treatment of epoxy aldehyde 767 with in situ zinc phenylacetylide followed by ring closure of the resulting alkoxide on the epoxide stereoselectively afforded α-C-alkynyl galactoside 768 in 73% yield.723 Reformatsky addition of diethyl zinc to a solution of aldehyde 769 and ethyl bromodifluoroacetate with the assistance of Wilkinson’s rhodium(I) catalyst led to a mixture of CF2glycoside 770 in low yield.724,725 Treatment of 1,2-oxazine 771

hydroxy-α,β-unsaturated aldehyde 756 with phenyl(trimethylsilyl) acetylene gave α-C-alkynyl glycoside 165 in 91% yield.700 The oxocarbenium ion cyclization of enol ether 757 promoted by MeOTf in the presence of DTBMP gave C-glycoside 758 in 78% yield (Scheme 127).701−707 Ring-closing metathesis of diene 759 with the second-generation Grubbs catalyst was carried out to produce C-glycoside 760 in good yield (>60%).708−718 Treatment of O-allyl ether 761 with PdCl2 in a mixture of NaOAc/HOAc/water gave ketal 762 in 82% yield.719 Reaction of isopropylidene-protected phenyl ketone 763 with iodine in methanol provided 2-deoxy-α-C-phenyl glycoside 764 in 76% 12325


Chemical Reviews

Review

Scheme 109. C-Glycosylation with Glycosyl Trichloroacetimidates through the O- → C-Glycoside Rearrangement

Scheme 110. C-Arylation with Glycosyl N-Phenyl Trifluoroacetimidates

Scheme 111. C-Glycosylation with Glycosyl N-Phenyl Trifluoroacetimidates through the O- → C-Glycoside Rearrangement

with TMSOTf induced the formation of an oxocarbenium ion by opening the dioxolane ring through coordination with the sterically less hindered oxygen atom, and subsequent electrophilic attack on the enol ether of the 1,2-oxazine ring provided ketone 772 in 76% yield with excellent stereoselectivity.726−729 Intramolecular Prins macrocyclization of aldehyde 773 in the presence of BF3·OEt2 and acetic acid effected the formation of βC-aryl glycosides 774 and 775 in yields of 33% and 48%, respectively.730

With respect to intermolecular cyclization, the SnCl4-catalyzed 1-oxa-Diels−Alder reaction of heterodiene 776 with enol ether 777 provided exclusively C-glycoside 778 in 66% yield (Scheme 128).731−733 Cycloaddition of Danishefsky’s diene 779 with aldehyde 780 in the presence of MgBr2 followed by treatment with trifluoroacetic acid gave dihydropyranone 781 (89%).734,735 A hetero-Diels−Alder reaction of diene 782 with diethyl mesoxalate 783 at 100 °C led to a 1:1 mixture of C-glycoside 784 and 785 in 82% yield.736 12326


Chemical Reviews

Review

Scheme 112. C-Glycosylation of Silylated Nucleophiles with Glycosyl Phosphates

Scheme 113. C-Sialylation of Silylated Nucleophiles with Glycosyl Phosphate 668

Scheme 114. C-Glycosylation with Glycosyl Phosphates through the O- → C-Glycoside Rearrangement

situ dichloroketene and subsequent exposure to zinc and acetic acid furnished cyclobutanone-containing C-glycoside 788 (90%).738−741 Under the promotion of SnCl4, Prins cyclization of homoallylic alcohol 789 with 790 gave a mixture of C-

Reaction of 2-nitroglucal 786 with diene 779 followed by aromatization through hydrolysis of the enol ether residue and elimination of the nitro and methoxy groups led to benzopyran 787 (40%) (Scheme 129).737 Cycloaddition of glucal 145 with in 12327


Chemical Reviews

Review

Scheme 115. C-Allylation with 1-O-Methyl Sugars

Scheme 116. Ultrasound-Assisted C-Allylation and CAllenylation with 1-O-Methyl Sugars

Scheme 118. C-Arylation with 1-O-Methyl Sugars

Scheme 117. Other C-Alkylation Reactions with 1-O-Methyl Sugars

glycoside 791 (82%).742,743 BF3·OEt2-promoted Sakurai cyclization of homoallylic alcohol 792 with crotonaldehyde 793 yielded tetrahydropyran 794 (53%).744,745 12328


Chemical Reviews

Review

Scheme 119. Synthesis of C-Glycosides through the Thermal Claisen Rearrangement

Scheme 120. Synthesis of C-Glycosides through the Claisen or Ireland−Claisen Rearrangement

Scheme 122. Synthesis of C-Glycosides through the Wittig Rearrangement or the Anomeric O → C Rearrangement

Scheme 121. Synthesis of C-Glycosides through the Ramberg−Bäcklund Rearrangement

12329


Chemical Reviews

Review

Scheme 123. Synthesis of C-Glycosides through Cyclization of δ-Hydroxy Alkenes

Scheme 124. Synthesis of C-Glycosides through Cyclization of γ-Hydroxy Alkenes

12330


Chemical Reviews

Review

Scheme 125. Synthesis of C-Glycosides through Cyclization of Diols

14. SYNTHESIS OF C-GLYCOSIDES WITH MISCELLANEOUS SUBSTRATES Although most C-glycosides can be synthesized by the chemical approaches described in the above sections, there are still other methods for the synthesis of C-glycosides, mostly through mechanisms similar to those depicted in Scheme 1. For instance, electrophilic glucosylation of 2′-carboxybenzyl glucoside with a range of C-nucleophiles, namely, allylsilane, 1,3-dimethoxybenzene, and furan, under the promotion of DTBMP and Tf2O afforded C-glucosides 348, 795, and 796 with complete αselectivity, whereas similar coupling with 1,2-dimethylindole led to a mixture of C-glucoside 797 in 85% yield (α/β = 1.7:1) (Scheme 130).746 4-Pentenyl glycosides 798 and 800 bearing 2-O-aryldiethylsilyl groups were treated with iodonium dicollidine perchlorate (IDCP) to afford, through intramolecular aglycone delivery, exclusively α-C-aryl glycosides 799 and 801 in high yields after removal of the silyl groups (Scheme 131).747 BF3·OEt2promoted C-glycosylation of glycosyl phosphorothioate 802 with allyltrimethylsilane gave α-C-allyl glucoside 348 as the single product in 84% yield, and reaction of 1-O-urea derivative 803 with allyltrimethylsilane under the promotion of SnBr4 afforded C-allyl glycoside 804 in 75% yield with a high diastereomeric ratio (dr = 8−9:1) (Scheme 132).748−750 Treatment of 1,6-anhydroglucose 805 with i-Bu2AlH followed by addition of aryl(chloro)alane 806 at 140 °C led to the opening of the 1,3-dioxolane ring and the formation of an ate complex between aryl(chloro)alane and the C-6-oxygen of the sugar derivative, which underwent β-face attack on the oxocarbenium ion to furnish canagliflozin 807 in 50% isolated yield with excellent β-selectivity (Scheme 133).10,751,752 TiCl4-mediated reaction of 2,7-dioxabicyclo[2.2.1]heptane 808 with allyltributylstannnane gave 2,5-trans-disubstituted tetrahydrofuran 809 as the predominant product (trans/cis = 93:7) in 84% yield (Scheme 134).753,754 C-Allylation of 1,2-O-isopropylidene furanose derivative 810 with allyltrimethylsilane under the promotion BF3·OEt2 probably proceeded through the inside attack of the stable oxocarbenium ion intermediate A, affording C-furanoside 811 with high 1,3-trans stereoselectivity in 65% yield (Scheme 134).755,756

Recently, the PPh3AuNTf2-catalyzed C-glycosylation of the glucosyl, 2-deoxyglucosyl, and 2-deoxyribofuranosyl orthoalkynylbenzoates with allylsilane was reported to provide Cglycosides 348, 812, and 813 in high yields (>80%) with the αanomers as the only or predomiant products (Scheme 135).757 When glucosyl ortho-alkynylbenzoate was subjected to 1styrenyloxytrimethylsilane or 4-methyl-2-trimethylsilyloxy-1pentene, C-glucosides 814 and 815 were obtained in good yields (>77%) with the α-anomers as the major products, whereas the reaction with 1-(trimethylsiloxy)-1-methoxy-1,3butadiene led to C-glucoside 816 in 80% yield, albeit with poor αselectivity (α/β = 1.5:1). Stille−Migata cross-coupling reactions of glycosyl stannanes (β-anomers, 817; α-anomers, 818) with aromatic iodides or bromides 819 were recently reported to afford the corresponding C-aryl glycosides with complete retention of either the α- or βanomeric configuration (Scheme 136).758 Thus, Pd2(dba)3catalyzed coupling of perbenzyl β-D-glucosyl tributylstannane with aromatic iodide or bromide 819 derived from phenyl- and N-containing heteroaromatic compounds, as well as phenylalanine peptide, in the presence of CuI, KF, and ligand L proceeded smoothly to give β-C-aryl glycosides 820−822 as the only products in 65−90% yields. This method was efficiently utilized for the synthesis of the protected antidiabetic drug dapagliflozin 823 (83%, β only) and C-glucoside 824 of the anticancer drug trametinib (80%, β only). Furthermore, Pd2(dba)3-catalyzed stereoretentive coupling of phenyl iodide with benzyl-protected β-glycosyl tributylstannanes derived from D-galactose, 2-N-acetyl-D-glucosamine, and 2-deoxy-D-glucose and with unprotected β-glucosyl tributylstannane produced β-Cphenyl glycosides 825−828 in 68−88% yields. In addition, switching β-glycosyl tributylstannanes 817 to α-glycosyl tributylstannanes 818 under similar coupling conditions furnished α-C-phenyl glycosides 829−833 with retention of the α-anomeric configuration in 51−92% yields. Et3B-assisted thermolysis of glucosyl diazirine 834 proceeded through nucleophilic attack of the resulting glycosylidene carbene on the borane derivative, and subsequent migration of a borane substituent provided glycosyl borane, which was oxidized by H2O2 under basic conditions to produce ketoside 12331


Chemical Reviews

Review

Scheme 126. Synthesis of C-Glycosides through Cyclization of Other Hydroxyl-Containing Substrates

835 in 60% yield (Scheme 137).759 Decomposition of diazosugar 836 in the presence of Rh2(OAc)4 proceeded through a 1,5insertion of metal carbene into the anomeric CH bond, furnishing ketopyranoside 837 in an efficient manner (56%).760,761 Treatment of 2-oxopropyl β-glucopyranoside 838 with lithium (trimethylsilyl)diazomethane at −78 °C generated alkylidenecarbene intermediate A, which underwent 1,5 CH bond insertion to provide spiroketal 839 in 85% yield with retention of the configuration.762,763

Interestingly, insertion of methyl acrylate into glucosylmanganese complex 840 followed by demetalation under photothermal conditions (hν, O2, H2O) led to enone 841 (50%) (Scheme 138).764 Photolysis of glucoside furanone derivative 842 led to the abstraction of 1-H and 5-H, providing tricyclic compounds 843−845 in low yields (843 and 844, 28%, α/β = 4:1; 845, 30%).765,766 Remarkably, de novo synthesis has also been employed for the synthesis of C-glycosides. Diol 847 derived from ketone 846 was subjected to a sequence of reactions 12332


Chemical Reviews

Review

Scheme 127. Synthesis of C-Glycosides through Other Types of Intramolecular Cyclizations

12333


Chemical Reviews

Review

Scheme 128. Synthesis of C-Glycosides through Hetero-Diels−Alder Reaction

Scheme 129. Synthesis of C-Glycosides through Other Types of Intermolecular Cyclizations

Scheme 130. C-Alkylation and C-Arylation with 2′-Carboxybenzyl Glucoside

12334


Chemical Reviews

Review

Scheme 131. C-Arylation with 4-Pentenyl Glycosides through Intramolecular Aglycone Delivery

Scheme 134. C-Allylation with 2,7Dioxabicyclo[2.2.1]heptane 808 and 1,2-O-Isopropylidene Furanose Derivative 810

Scheme 132. C-Glycosylation with Glycosyl Phosphorothioate 802 and 1-O-Urea Derivative 803

Scheme 133. C-Arylation with 1,6-Anhydroglucose 805

involving ozonolysis, reduction with NaBH4, and formation of benzylidene acetal to furnish C-glycoside 848 in a stereocontrolled fashion (64%).767−769

construction of the glycosidic CC bonds. In contrast to conventional CC bond formation in organic synthesis, glycosidic CC bonds have been effectively constructed mainly by various C-glycosylation methods that involve glycosyl cationic/anionic/radical species and transition-metal complexes derived from a series of sugar precursors. Rearrangements and cyclizations provide alternative avenues to the synthesis of C-glycosides. The inherent complexity of carbohydrates, specifically, the polyhydroxylated structures with multiple stereocenters and various protecting groups, renders the stereocontrolled synthesis of the target C-glycosides quite challenging. Variable stereoselectivities are

15. CONCLUSIONS In light of the successful development of C-glycosides as inhibitors of glycosidases and glycosyltransferases, modulators of a series of biological processes, and drugs against various diseases, the synthesis of C-glycosides has become a rapidly growing field in the past few decades. The key issue in the synthesis of C-glycosides is the 12335


Chemical Reviews

Review

Scheme 135. C-Alkylation with Glycosyl ortho-Alkynylbenzoates

Scheme 136. C-Arylation with Glycosyl Stannanes by Stille−Migata Cross-Coupling

12336


Chemical Reviews

Review

Scheme 137. Synthesis of C-Glycosides through Carbene Species

Scheme 138. Synthesis of C-Glycosides with Other Substrates

AUTHOR INFORMATION

often encountered in C-glycosylation reactions with different substrates. The exact mechanisms and the underlying principles for the stereoselective C-glycosylation reactions still remain incompletely understood. The harsh conditions employed in many of the Cglycosylation reactions and the difficulty of preparing the sugar precursors (such as the 1,2-anhydro sugars) restrict the functionalgroup tolerance of complex C-glycoside syntheses. To meet these challenges, the development of mild, general, and stereospecific Cglycosylation methods with easily prepared sugar precursors and the elucidation of the mechanisms of C-glycosylation are still intensely needed. Continuous efforts in this rapidly growing area toward identifying the fundamental rules that control the stereoselectivity of Cglycosylation would allow for the synthesis of a wide range of structurally complex and biologically significant C-glycosides. As the synthetic toolbox of C-glycosides is further expanding, a more diverse collection of C-glycosides would be available to facilitate the development of valuable probes for understanding the mechanisms of carbohydrate-processing enzymes as well as carbohydrate drugs.

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. ORCID

You Yang: 0000-0003-4438-2162 Biao Yu: 0000-0002-3607-578X Notes

The authors declare no competing financial interest. Biographies You Yang received his B.S. in Chemistry from University of Science and Technology of China (USTC) in 2004. He completed his Ph.D. at Shanghai Institute of Organic Chemistry (SIOC), Chinese Academy of Sciences (CAS), in collaboration with USTC in 2010 under the supervision of Prof. Biao Yu. After four years of postdoctoral research with Prof. Peter H. Seeberger at Max Planck Institute of Colloids and Interfaces, he was appointed as an Associate Professor at East China University of Science and Technology (ECUST) in 2014 and promoted 12337


Chemical Reviews

Review

(14) Cavezza, A.; Boulle, C.; Gueguiniat, A.; Pichaud, P.; Trouille, S.; Ricard, L.; Dalko-Csiba, M. Synthesis of Pro-Xylane: a new biologically active C-glycoside in aqueous media. Bioorg. Med. Chem. Lett. 2009, 19, 845−849. (15) Wei, A.; Boy, K. M.; Kishi, Y. Biological evaluation of rationally modified analogs of the H-type II blood group trisaccharide. A correlation between solution conformation and binding affinity. J. Am. Chem. Soc. 1995, 117, 9432−9436. (16) Hultin, P. G. Bioactive C-glycosides from bacterial secondary metabolism. Curr. Top. Med. Chem. 2005, 5, 1299−1331. (17) Bililign, T.; Griffith, B. R.; Thorson, J. S. Structure, activity, synthesis and biosynthesis of aryl-C-glycosides. Nat. Prod. Rep. 2005, 22, 742−760. (18) Franz, G.; Grün, M. Chemistry, occurrence and biosynthesis of Cglycosyl compounds in plants. Planta Med. 1983, 47, 131−140. (19) He, X.; Blount, J. W.; Ge, S.; Tang, Y.; Dixon, R. A. A genomic approach to isoflavone biosynthesis in kudzu (Pueraria lobata). Planta 2011, 233, 843−855. (20) Ehianeta, T. S.; Laval, S.; Yu, B. Bio- and chemical syntheses of mangiferin and congeners. Biofactors 2016, 42, 445−458. (21) Baig, I.; Kharel, M.; Kobylyanskyy, A.; Zhu, L.; Rebets, Y.; Ostash, B.; Luzhetskyy, A.; Bechthold, A.; Fedorenko, V. A.; Rohr, J. On the acceptor substrate of C-glycosyltransferase urdGT2: three prejadomycin C-Glycosides from an engineered mutant of Streptomyces globisporus 1912 ΔlndE (urdGT2). Angew. Chem., Int. Ed. 2006, 45, 7842−7846. (22) Brazier-Hicks, M.; Evans, K. M.; Gershater, M. C.; Puschmann, H.; Steel, P. G.; Edwards, R. The C-glycosylation of flavonoids in cereals. J. Biol. Chem. 2009, 284, 17926−17934. (23) Gutmann, A.; Nidetzky, B. Switching between O- and Cglycosyltransferase through exchange of active-site motifs. Angew. Chem., Int. Ed. 2012, 51, 12879−12883. (24) Gutmann, A.; Nidetzky, B. Enzymatic C-glycosylation: insights from the study of a complementary pair of plant O- and Cglucosyltransferases. Pure Appl. Chem. 2013, 85, 1865−1877. (25) Nagatomo, Y.; Usui, S.; Ito, T.; Kato, A.; Shimosaka, M.; Taguchi, G. Purification, molecular cloning and functional characterization of flavonoid C-glucosyltransferases from Fagopyrum esculentum M. (buckwheat) cotyledon. Plant J. 2014, 80, 437−448. (26) Chen, D.; Chen, R.; Wang, R.; Li, J.; Xie, K.; Bian, C.; Sun, L.; Zhang, X.; Liu, J.; Yang, L.; Ye, F.; Yu, X.; Dai, J. Probing the catalytic promiscuity of a regio- and stereospecific C-glycosyltransferase from Mangifera indica. Angew. Chem., Int. Ed. 2015, 54, 12678−12682. (27) Hungerford, N. L.; Armitt, D. J.; Banwell, M. G. Syntheses of showdomycin and its anomer using N-(triisopropylsilyl)pyrrole as a synthetic equivalent for the maleimide C3-anion. Synthesis 2003, 1837− 1843. (28) Zeng, J.; Vedachalam, S.; Xiang, S.; Liu, X.-W. Direct Cglycosylation of organotrifluoroborates with glycosyl fluorides and its application to the total synthesis of (+)-Varitriol. Org. Lett. 2011, 13, 42−45. (29) Donohoe, T. J.; Winship, P. C. M.; Tatton, M. R.; Szeto, P. A short and efficient synthesis of neodysiherbaine A by using catalytic oxidative cyclization. Angew. Chem., Int. Ed. 2011, 50, 7604−7606. (30) Liu, P.; Jacobsen, E. N. Total synthesis of (+)-ambruticin. J. Am. Chem. Soc. 2001, 123, 10772−10773. (31) Parkan, K.; Pohl, R.; Kotora, M. Cross-coupling reaction of saccharide-based alkenyl boronic acids with aryl halides: the synthesis of bergenin. Chem. - Eur. J. 2014, 20, 4414−4419. (32) Denmark, S. E.; Regens, C. S.; Kobayashi, T. Total synthesis of papulacandin D. J. Am. Chem. Soc. 2007, 129, 2774−2776. (33) Han, Z.; Achilonu, M. C.; Kendrekar, P. S.; Joubert, E.; Ferreira, D.; Bonnet, S. L.; van der Westhuizen, J. H. Concise and scalable synthesis of aspalathin, a powerful plasma sugar-lowering natural product. J. Nat. Prod. 2014, 77, 583−588. (34) Lee, D. Y. W.; Zhang, W.-Y.; Karnati, V. V. R. Total synthesis of puerarin, an isoflavone C-glycoside. Tetrahedron Lett. 2003, 44, 6857− 6859.

to a Full Professor in 2015. His research interests include carbohydrate chemistry and carbohydrate-based therapeutics. Biao Yu received his B.S. in Radiochemistry from Peking University in 1989 and his Ph.D. (with Prof. Y. Hui) from Shanghai Institute of Organic Chemistry (SIOC), Chinese Academy of Sciences (CAS), in 1995. After a one-year postdoctoral stay at New York University, Dr. Yu returned to SIOC as an Assistant Professor and became a Professor in 1999. His laboratory is dedicated to the total synthesis, synthetic methodology, and chemical biology of oligosaccharides and glycoconjugates.

ACKNOWLEDGMENTS Financial support from the National Thousand Young Talents Program (YC0130518, YC0140103), the Ministry of Science and Technology of China (2012ZX09502-002), the National Natural Science Foundation of China (21432012 and 21621002), the Strategic Priority Research Program of the CAS (XDB20020000), the K. C. Wong Education Foundation, and the Shanghai Pujiang Program (15PJ1401500) is gratefully acknowledged. REFERENCES (1) Dondoni, A.; Marra, A. Methods for anomeric carbon-linked and fused sugar amino acid synthesis: the gateway to artificial glycopeptides. Chem. Rev. 2000, 100, 4395−4421. (2) Koester, D. C.; Holkenbrink, A.; Werz, D. B. Recent advances in the synthesis of carbohydrate mimetics. Synthesis 2010, 2010, 3217− 3242. (3) Leclerc, E.; Pannecoucke, X.; Etheve-Quelquejeu, M.; Sollogoub, M. Fluoro-C-glycosides and fluoro-carbasugars, hydrolytically stable and synthetically challenging glycomimetics. Chem. Soc. Rev. 2013, 42, 4270−4283. (4) Zou, W. C-Glycosides and aza-C-glycosides as potential glycosidase and glycosyltransferase inhibitors. Curr. Top. Med. Chem. 2005, 5, 1363−1391. (5) Compain, P.; Martin, O. R. Carbohydrate mimetics-based glycosyltransferase inhibitors. Bioorg. Med. Chem. 2001, 9, 3077−3092. (6) Yang, G.; Schmieg, J.; Tsuji, M.; Franck, R. W. The C-glycoside analogue of the immunostimulant α-galactosylceramide (KRN7000): synthesis and striking enhancement of activity. Angew. Chem., Int. Ed. 2004, 43, 3818−3822. (7) Franck, R. W.; Tsuji, M. α-C-Galactosylceramides: synthesis and immunology. Acc. Chem. Res. 2006, 39, 692−701. (8) Chao, E. C.; Henry, R. R. SGLT2 inhibition − a novel strategy for diabetes treatment. Nat. Rev. Drug Discovery 2010, 9, 551−559. (9) Wang, X.-J.; Zhang, L.; Byrne, D.; Nummy, L.; Weber, D.; Krishnamurthy, D.; Yee, N.; Senanayake, C. H. Efficient synthesis of empagliflozin, an inhibitor of SGLT-2, utilizing an AlCl3-promoted silane reduction of a β-glycopyranoside. Org. Lett. 2014, 16, 4090−4093. (10) Henschke, J. P.; Lin, C.-W.; Wu, P.-Y.; Tsao, W.-S.; Liao, J.-H.; Chiang, P.-C. β-Selective C-arylation of diisobutylaluminum hydride modified 1,6-anhydroglucose: synthesis of canagliflozin without recourse to conventional protecting groups. J. Org. Chem. 2015, 80, 5189−5195. (11) Guo, C.; Hu, M.; DeOrazio, R. J.; Usyatinsky, A.; Fitzpatrick, K.; Zhang, Z.; Maeng, J.-H.; Kitchen, D. B.; Tom, S.; Luche, M.; Khmelnitsky, Y.; Mhyre, A. J.; Guzzo, P. R.; Liu, S. The design and synthesis of novel SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties. Bioorg. Med. Chem. 2014, 22, 3414−3422. (12) Cai, W.; Jiang, L.; Xie, Y.; Liu, Y.; Liu, W.; Zhao, G. Design of SGLT2 inhibitors for the treatment of type 2 diabetes: a history driven by biology to chemistry. Med. Chem. 2015, 11, 317−328. (13) Leseurre, L.; Merea, C.; Duprat de Paule, S.; Pinchart, A. Ecofootprint: a new tool for the “Made in Chimex” considered approach. Green Chem. 2014, 16, 1139−1148. 12338


Chemical Reviews

Review

(35) Wu, Z.; Wei, G.; Lian, G.; Yu, B. Synthesis of mangiferin, isomangiferin, and homomangiferin. J. Org. Chem. 2010, 75, 5725− 5728. (36) Furuta, T.; Nakayama, M.; Suzuki, H.; Tajimi, H.; Inai, M.; Nukaya, H.; Wakimoto, T.; Kan, T. Concise synthesis of chafurosides A and B. Org. Lett. 2009, 11, 2233−2236. (37) Futagami, S.; Ohashi, Y.; Imura, K.; Hosoya, T.; Ohmori, K.; Matsumoto, T.; Suzuki, K. Total synthesis of ravidomycin: revision of absolute and relative stereochemistry. Tetrahedron Lett. 2000, 41, 1063− 1067. (38) Matsumoto, T.; Hosoya, T.; Suzuki, K. Total synthesis and absolute stereochemical assignment of gilvocarcin M. J. Am. Chem. Soc. 1992, 114, 3568−3570. (39) Koyama, Y.; Yamaguchi, R.; Suzuki, K. Total synthesis and structure assignment of the anthrone C-glycoside cassialoin. Angew. Chem., Int. Ed. 2008, 47, 1084−1087. (40) Tatsuta, K.; Ozeki, H.; Yamaguchi, M.; Tanaka, M.; Okui, T. Enantioselective total synthesis of medermycin (lactoquinomycin). Tetrahedron Lett. 1990, 31, 5495−5498. (41) Kitamura, K.; Maezawa, Y.; Ando, Y.; Kusumi, T.; Matsumoto, T.; Suzuki, K. Synthesis of the pluramycins 2: total synthesis and structure assignment of saptomycin B. Angew. Chem., Int. Ed. 2014, 53, 1262− 1265. (42) Krohn, K.; Agocs, A.; Bäuerlein, C. Total synthesis of angucyclines. XVII. First synthesis of antibiotic 100−1, a deoxydisaccharide angucycline antibiotic of the urdamycinone B-type. J. Carbohydr. Chem. 2003, 22, 579−592. (43) Yuan, Y.; Men, H.; Lee, C. Total synthesis of kendomycin: a macro-C-glycosidation approach. J. Am. Chem. Soc. 2004, 126, 14720− 14721. (44) Hanessian, S. Total Synthesis of Natural Products: The ‘Chiron’ Approach; Marcel Dekker: New York, 1983. (45) Hollingsworth, R. I.; Wang, G. Toward a carbohydrate-based chemistry: progress in the development of general-purpose chiral synthons from carbohydrates. Chem. Rev. 2000, 100, 4267−4282. (46) Nicolaou, K. C.; Mitchell, H. J. Adventures in carbohydrate chemistry: new synthetic technologies, chemical synthesis, molecular design, and chemical biology. Angew. Chem., Int. Ed. 2001, 40, 1576− 1624. (47) Sharma, G. V. M; Krishna, P. R. Carbohydrates: from ‘chirons’ to new glycosubstances. Curr. Org. Chem. 2004, 8, 1187−1209. (48) Pathak, T. Vinyl sulfone-modified carbohydrates: an inconspicuous group of chiral building blocks. Tetrahedron 2008, 64, 3605− 3628. (49) Levy, D. E.; Tang, C. The Chemistry of C-Glycosides; Pergamon Press: Oxford, U.K., 1995. (50) Postema, M. H. D. C-Glycoside Synthesis; CRC Press: Boca Raton, FL, 1995. (51) Du, Y.; Linhardt, R. J.; Vlahov, I. R. Recent advances in stereoselective C-glycoside synthesis. Tetrahedron 1998, 54, 9913− 9959. (52) Postema, M. H. D. Recent developments in the synthesis of Cglycosides. Tetrahedron 1992, 48, 8545−8599. (53) Nicotra, F. Synthesis of C-glycosides of biological interest. Top. Curr. Chem. 1997, 187, 55−83. (54) Taillefumier, C.; Chapleur, Y. Synthesis and uses of exo-glycals. Chem. Rev. 2004, 104, 263−292. (55) Lin, C.-H.; Lin, H.-C.; Yang, W.-B. exo-Glycal chemistry: general aspects and synthetic applications for biomedical use. Curr. Top. Med. Chem. 2005, 5, 1431−1457. (56) Yuan, X.; Linhardt, R. J. Recent advances in the synthesis of Coligosaccharides. Curr. Top. Med. Chem. 2005, 5, 1393−1430. (57) Liu, L.; McKee, M.; Postema, M. H. D. Synthesis of C-saccharides and higher congeners. Curr. Org. Chem. 2001, 5, 1133−1167. (58) von Moos, E.; Ben, R. N. Recent advances in the synthesis of Clinked glycoconjugates. Curr. Top. Med. Chem. 2005, 5, 1351−1361. (59) Lee, D. Y. W.; He, M. Recent advances in aryl C-glycoside synthesis. Curr. Top. Med. Chem. 2005, 5, 1333−1350.

(60) Bokor, E.; Kun, S.; Goyard, D.; Toth, M.; Praly, J.-P.; Vidal, S.; Somsak, L. C-Glycopyranosyl arenes and hetarenes: synthetic methods and bioactivity focused on antidiabetic potential. Chem. Rev. 2017, 117, 1687−1764. (61) Stambasky, J.; Hocek, M.; Kocovsky, P. C-Nucleosides: synthetic strategies and biological applications. Chem. Rev. 2009, 109, 6729−6764. (62) Adamo, M. F. A.; Pergoli, R. Synthesis and medicinal properties of 2-deoxyribose and ribose C-nucleosides. Curr. Org. Chem. 2008, 12, 1544−1569. (63) Choumane, M.; Banchet, A.; Probst, N.; Gerard, S.; Ple, K.; Haudrechy, A. The synthesis of D-C-mannopyranosides. C. R. Chim. 2011, 14, 235−273. (64) Lalitha, K.; Muthusamy, K.; Prasad, Y. S.; Vemula, P. K.; Nagarajan, S. Recent developments in β-C-glycosides: synthesis and applications. Carbohydr. Res. 2015, 402, 158−171. (65) Beau, J.-M.; Gallagher, T. Nucleophilic C-glycosyl donors for Cglycoside synthesis. Top. Curr. Chem. 1997, 187, 1−54. (66) Togo, H.; He, W.; Waki, Y.; Yokoyama, M. C-Glycosylation technology with free radical reactions. Synlett 1998, 1998, 700−717. (67) Somsak, L. Carbanionic reactivity of the anomeric center in carbohydrates. Chem. Rev. 2001, 101, 81−135. (68) Merino, P.; Tejero, T.; Marca, E.; Gomollon-Bel, F.; Delso, I.; Matute, R. Cross-coupling reactions for the synthesis of C-glycosides and related compounds. Heterocycles 2012, 86, 791−820. (69) Wellington, K. W.; Benner, S. A. A review: synthesis of aryl Cglycosides via the Heck coupling reaction. Nucleosides, Nucleotides Nucleic Acids 2006, 25, 1309−1333. (70) Györgydeak, Z.; Pelyvas, I. F. C-Glycosylation. In Glycoscience: Chemistry and Chemical Biology I−III; Fraser-Reid, B. O., Tatsuta, K., Thiem, J., Eds; Springer: Berlin, 2001; pp 691−747. (71) Levy, D. E. Strategies towards C-Glycosides. In The Organic Chemistry of Sugars; Levy, D. E., Fugedi, P., Eds; CRC Press: Boca Raton, FL, 2006; pp 269−348. (72) Nishikawa, T.; Adachi, M.; Isobe, M. C-Glycosylation. In Glycoscience; Fraser-Reid, B., Tatsuta, K., Thiem, J., Eds.; SpringerVerlag: Berlin, 2008; pp 755−811. (73) Compain, P.; Martin, O. R. Iminosugars: From Synthesis to Therapeutic Applications; John Wiley & Sons: Hoboken, NJ, 2007. (74) Compain, P.; Chagnault, V.; Martin, O. R. Tactics and strategies for the synthesis of iminosugar C-glycosides: a review. Tetrahedron: Asymmetry 2009, 20, 672−711. (75) Arjona, O.; Gomez, A. M.; Lopez, J. C.; Plumet, J. Synthesis and conformational and biological aspects of carbasugars. Chem. Rev. 2007, 107, 1919−2036. (76) Yuasa, H.; Izumi, M.; Hashimoto, H. Thiasugars: potential glycosidase inhibitors. Curr. Top. Med. Chem. 2009, 9, 76−86. (77) Zhu, X.; Schmidt, R. R. New principles for glycoside-bond formation. Angew. Chem., Int. Ed. 2009, 48, 1900−1934. (78) Yang, Y.; Zhang, X.; Yu, B. O-Glycosylation methods in the total synthesis of complex natural glycosides. Nat. Prod. Rep. 2015, 32, 1331− 1355. (79) Hurd, S. D.; Bonner, W. A. The reaction of tetraacetylglucosyl chloride with aromatic hydrocarbons in the presence of aluminum chloride. J. Am. Chem. Soc. 1945, 67, 1664−1668. (80) Hanessian, S.; Pernet, A. G. Carbanions in carbohydrate chemistry: a new synthesis of C-glycosyl compounds. J. Chem. Soc. D 1971, 755−756. (81) Nicolaou, K. C.; Dolle, R. E.; Chucholowski, A.; Randall, J. L. Reactions of glycosyl fluorides. Synthesis of C-glycosides. J. Chem. Soc., Chem. Commun. 1984, 1153−1154. (82) Lancelin, J.-M.; Morin-Allory, L.; Sinay, P. Simple generation of a reactive glycosyl-lithium derivative. J. Chem. Soc., Chem. Commun. 1984, 355−356. (83) Praly, J.-P. Structure of anomeric glycosyl radicals and their transformation under reductive conditions. Adv. Carbohydr. Chem. Biochem. 2000, 56, 65−151. (84) Buckmelter, A. J.; Kim, A. I.; Rychnovsky, S. D. Conformational memory in enantioselective radical reductions and a new radical clock reaction. J. Am. Chem. Soc. 2000, 122, 9386−9390. 12339


Chemical Reviews

Review

chlorides by treatment with organolithium reagents. Eur. J. Org. Chem. 2009, 2009, 3579−3588. (108) Gomez, A. M.; Pedregosa, A.; Barrio, A.; Valverde, S.; Lopez, J. C. Synthesis of furanosyl C-1 glycals through palladium-catalyzed reactions of a furanosyl 2,3-anhydro-exo-glycal. Eur. J. Org. Chem. 2009, 2009, 4627−4636. (109) Gomez, A. M.; Casillas, M.; Rodriguez, B.; Valverde, S.; Lopez, J. C. Synthesis of furanoid and pyranoid C-1 aryl glycals by reaction of glycosyl chlorides with organolithium reagents. ARKIVOC 2010, 2010 (iii), 288−302. (110) Gomez, A. M.; Pedregosa, A.; Valverde, S.; Lopez, J. C. A synthetic route to pyranoid epoxy-exo-glycals from D-glucose. ARKIVOC 2011, No. iii , 33−41. (111) Toshima, K. Glycosyl fluorides in glycosidations. Carbohydr. Res. 2000, 327, 15−26. (112) Kanai, A.; Kamino, T.; Kuramochi, K.; Kobayashi, S. Synthetic studies directed toward the assembly of the C-glycoside fragment of the telomerase inhibitor D8646-2-6. Org. Lett. 2003, 5, 2837−2839. (113) Misawa, K.; Gunji, Y.; Sato, S. Concise synthesis of flavocommelin, 7-O-methylapigenin 6-C-, 4′-O-bis-β-D-glucoside, a component of the blue supramolecular pigment from Commelina communis. Carbohydr. Res. 2013, 374, 8−13. (114) Kumazawa, T.; Minatogawa, T.; Matsuba, S.; Sato, S.; Onodera, J.-i. An effective synthesis of isoorientin: the regioselective synthesis of a 6-C-glucosylflavone. Carbohydr. Res. 2000, 329, 507−513. (115) Kumazawa, T.; Sato, S.; Matsuba, S.; Onodera, J.-i. Synthesis of C-mannopyranosylphloroacetophenone derivatives and their anomerization. Carbohydr. Res. 2001, 332, 103−108. (116) Kumazawa, T.; Kimura, T.; Matsuba, S.; Sato, S.; Onodera, J.-i. Synthesis of 8-C-glucosylflavones. Carbohydr. Res. 2001, 334, 183−193. (117) Kumazawa, T.; Onda, K.; Okuyama, H.; Matsuba, S.; Sato, S.; Onodera, J.-i. Synthesis of C-glycopyranosylphloroacetophenone derivatives and their anomerization facilitated by 1,3-diaxial interactions. Carbohydr. Res. 2002, 337, 1007−1013. (118) Sato, S.; Hiroe, K.; Kumazawa, T.; Onodera, J.-i. Total synthesis of two isoflavone C-glycosides: genistein and orobol 8-C-β-Dglucopyranosides. Carbohydr. Res. 2006, 341, 1091−1095. (119) Nakatsuka, T.; Tomimori, Y.; Fukuda, Y.; Nukaya, H. First total synthesis of structurally unique flavonoids and their strong antiinflammatory effect. Bioorg. Med. Chem. Lett. 2004, 14, 3201−3203. (120) Hayashi, T.; Ohmori, K.; Suzuki, K. Synthetic study on carthamin. 2. stereoselective approach to C-glycosyl quinochalcone via desymmetrization. Org. Lett. 2017, 19, 866−869. (121) Nakayama, R.; Tanzer, E.-M.; Kusumi, T.; Ohmori, K.; Suzuki, K. Total synthesis of the proposed structure of ardimerin, and proposal for its structural revision. Helv. Chim. Acta 2016, 99, 944−960. (122) Hayashi, T.; Ohmori, K.; Suzuki, K. Synthetic study on carthamin: problem and solution for oxidative dearomatization approach to quinol C-glycoside. Synlett 2016, 27, 2345−2351. (123) Chan, K. L.; Coumbarides, G. S.; Islam, S.; Wyatt, P. B. Synthesis of propargyl C-glycosides using allenyltributylstannane. Tetrahedron Lett. 2005, 46, 61−65. (124) Lubin-Germain, N.; Baltaze, J.-P.; Coste, A.; Hallonet, A.; Laureano, H.; Legrave, G.; Uziel, J.; Auge, J. Direct C-glycosylation by indium-mediated alkynylation on sugar anomeric position. Org. Lett. 2008, 10, 725−728. (125) Ichikawa, S.; Hayashi, R.; Hirano, S.; Matsuda, A. Highly βselective C-allylation of a ribofuranoside controlling steric hindrance in the transition state. Org. Lett. 2008, 10, 5107−5110. (126) Larsen, C. H.; Ridgway, B. H.; Shaw, J. T.; Smith, D. M.; Woerpel, K. A. Stereoselective C-glycosylation reactions of ribose derivatives: electronic effects of five-membered ring oxocarbenium ions. J. Am. Chem. Soc. 2005, 127, 10879−10884. (127) Tamura, S.; Abe, H.; Matsuda, A.; Shuto, S. Control of α/β stereoselectivity in Lewis acid promoted C-glycosidations using a controlling anomeric effect based on the conformational restriction strategy. Angew. Chem., Int. Ed. 2003, 42, 1021−1023. (128) Meloncelli, P. J.; Martin, A. D.; Lowary, T. L. Glycosyl iodides. History and recent advances. Carbohydr. Res. 2009, 344, 1110−1122.

(85) Keck, G. E.; Yates, J. B. Carbon-carbon bond formation via the reaction of trialkylallylstannanes with organic halides. J. Am. Chem. Soc. 1982, 104, 5829−5831. (86) Giese, B.; Dupuis, J. DiastereoseIective syntheses of Cglycopyranosides. Angew. Chem., Int. Ed. Engl. 1983, 22, 622−623. (87) Descotes, G. Radical anomeric chemistry. J. Carbohydr. Chem. 1988, 7, 1−20. (88) McKay, M. J.; Nguyen, H. M. Recent advances in transition metalcatalyzed glycosylation. ACS Catal. 2012, 2, 1563−1595. (89) Gong, H.; Sinisi, R.; Gagne, M. R. A room temperature Negishi cross-coupling approach to C-alkyl glycosides. J. Am. Chem. Soc. 2007, 129, 1908−1909. (90) Katajisto, J.; Lönnberg, H. Solid-phase synthesis of cyclic Cglycoside/amino acid hybrids by carbamate coupling chemistry and onsupport cyclization. Eur. J. Org. Chem. 2005, 2005, 3518−3525. (91) Mikata, Y.; Inaba, Y.; Morioka, M.; Yano, S. General synthesis of sugar-pendant 1,3-propanediamines containing a C-glycoside linkage. Tetrahedron Lett. 2004, 45, 8785−8788. (92) Inaba, Y.; Yano, S.; Mikata, Y. Preparation of C-glycoside pendant β2- and β2,2-amino acids. Bull. Chem. Soc. Jpn. 2008, 81, 606−616. (93) Inaba, Y.; Yano, S.; Mikata, Y. Facile synthesis of 2-(β-Cglucopyranosyl)-β-amino acid: a new class of glycopeptide building block. Tetrahedron Lett. 2007, 48, 993−997. (94) Suhara, Y.; Yamaguchi, Y.; Collins, B.; Schnaar, R. L.; Yanagishita, M.; Hildreth, J. E. K.; Shimada, I.; Ichikawa, Y. Oligomers of glycamino acid. Bioorg. Med. Chem. 2002, 10, 1999−2013. (95) Marca, E.; Valero-Gonzalez, J.; Delso, I.; Tejero, T.; HurtadoGuerrero, R.; Merino, P. Synthesis of O- and C-glycosides derived from β-(1,3)-D-glucans. Carbohydr. Res. 2013, 382, 9−18. (96) Ko, K.-S.; Kruse, J.; Pohl, N. L. Synthesis of isobutyl-C-galactoside (IBCG) as an isopropylthiogalactoside (IPTG) substitute for increased induction of protein expression. Org. Lett. 2003, 5, 1781−1783. (97) Lemaire, S.; Houpis, I. N.; Xiao, T.; Li, J.; Digard, E.; Gozlan, C.; Liu, R.; Gavryushin, A.; Diene, C.; Wang, Y.; Farina, V.; Knochel, P. Stereoselective C-glycosylation reactions with arylzinc reagents. Org. Lett. 2012, 14, 1480−1483. (98) Barroso, S.; Lemaire, S.; Farina, V.; Steib, A. K.; Blanc, R.; Knochel, P. cine Substitution with arylzinc reagents: scope and mechanistic studies. J. Org. Chem. 2016, 81, 2804−2816. (99) Mukherjee, D.; Sarkar, S. K.; Chowdhury, U. S.; Taneja, S. C. A rapid stereoselective C-glycosidation of indoles and pyrrole via indium trichloride promoted reactions of glycosyl halides. Tetrahedron Lett. 2007, 48, 663−667. (100) Carriere, D.; Meunier, S. J.; Tropper, F. D.; Cao, S.; Roy, R. Phase transfer catalysis toward the synthesis of O-, S-, Se- and Cglycosides. J. Mol. Catal. A: Chem. 2000, 154, 9−22. (101) Doboszewski, B. D-Arabinose-based synthesis of homo-C-d4T and homo-C-thymidine. Nucleosides, Nucleotides Nucleic Acids 2009, 28, 875−901. (102) Hocek, M.; Pohl, R.; Klepetarova, B. A new modular and practical methodology for the synthesis of 4- or 3-substituted phenyl Cnucleosides. Eur. J. Org. Chem. 2005, 2005, 4525−4528. (103) Jazouli, M.; Guianvarc’h, D.; Soufiaoui, M.; Bougrin, K.; Vierling, P.; Benhida, R. A short and efficient synthesis of 2′-deoxybenzo- and pyridoimidazole C-nucleosides. Tetrahedron Lett. 2003, 44, 5807−5810. (104) Koikov, L. N.; Smoliakova, I. P.; Liu, H. One-pot synthesis of Cglycosylic compounds (C-glycosides) from D-glucal, p-tolylsulfenyl chloride and aromatic/heteroaromatic compounds in the presence of Lewis acids. Carbohydr. Res. 2002, 337, 1275−1283. (105) Liu, H.; Smoliakova, I. P. Stereoselective synthesis of β-Cglucopyranosides using the reaction of TMSCN and Grignard reagents with cyclic five-membered sulfonium salt intermediates. Tetrahedron 2001, 57, 2973−2980. (106) Liu, H.; Smoliakova, I. P.; Koikov, L. N. A one-pot synthesis of βC-glucopyranosides from exo-glucal, p-tolylsulfenyl chloride, an αmethoxyalkene, and an external nucleophile. Org. Lett. 2002, 4, 3895− 3898. (107) Gomez, A. M.; Pedregosa, A.; Casillas, M.; Uriel, C.; Lopez, J. C. Synthesis of C-1 alkyl and aryl glycals from pyranosyl or furanosyl 12340


Chemical Reviews

Review

(129) Baldoni, L.; Marino, C. Synthesis of S- and C-galactofuranosides via a galactofuranosyl iodide. Isolable 1-galactofuranosylthiol derivative as a new glycosyl donor. Carbohydr. Res. 2012, 362, 70−78. (130) Bhat, A. S.; Gervay-Hague, J. Efficient syntheses of βcyanosugars using glycosyl iodides derived from per-O-silylated mono- and disaccharides. Org. Lett. 2001, 3, 2081−2084. (131) Kulkarni, S. S.; Gervay-Hague, J. Efficient synthesis of a Canalogue of the immunogenic bacterial glycolipid BbGL2. Org. Lett. 2006, 8, 5765−5768. (132) Jarosz, S.; Zamojski, A. Carbohydrate derivatives containing the carbon-lithium and carbon-tin bonds. Curr. Org. Chem. 2003, 7, 13−33. (133) Schäfer, A.; Thiem, J. Synthesis of novel donor mimetics of UDP-Gal, UDP-GlcNAc, and UDP-GalNAc as potential transferase inhibitors. J. Org. Chem. 2000, 65, 24−29. (134) Miquel, N.; Doisneau, G.; Beau, J.-M. Synthesis of 1,2-trans Cglycosyl compounds by reductive samariation of glycosyl iodides. Chem. Commun. 2000, 2347−2348. (135) Baytas, S. N.; Wang, Q.; Karst, N. A.; Dordick, J. S.; Linhardt, R. J. Solid-phase chemoenzymatic synthesis of C-sialosides. J. Org. Chem. 2004, 69, 6900−6903. (136) Diaz, G.; Ponzinibbio, A.; Bravo, R. D. Synthesis of novel 2deoxy-β-benzyl-C-glycosides by highly stereo- and chemoselective hydrogenation of exo-glycals. Carbohydr. Res. 2014, 393, 23−25. (137) Lichtenthaler, F. W.; Lergenmüller, M.; Schwidetzky, S. CGlycosidations of a 2-ketohexosyl bromide with electrophilic, radical, and nucleophilic anomeric carbons. Eur. J. Org. Chem. 2003, 2003, 3094−3103. (138) Manabe, S.; Aihara, Y.; Ito, Y. Radical C-glycosylation reaction of pyranosides with the 2,3-trans carbamate group. Chem. Commun. 2011, 47, 9720−9722. (139) Dubber, M.; Lindhorst, T. K. Synthesis of a carbohydratecentered C-glycoside cluster. J. Carbohydr. Chem. 2001, 20, 755−760. (140) Babic, A.; Gobec, S.; Gravier-Pelletier, C.; Le Merrer, Y.; Pecar, S. Synthesis of 1-C-linked diphosphate analogues of UDP-N-Acglucosamine and UDP-N-Ac-muramic acid. Tetrahedron 2008, 64, 9093−9100. (141) Wakabayashi, T.; Shiozaki, M.; Kurakata, S.-i. Practical stereoselective synthesis of α-linked C-glucosamine propionic acid esters: conversion to GLA-60 derivatives. Carbohydr. Res. 2002, 337, 97−104. (142) Praly, J.-P.; Chen, G.-R.; Gola, J.; Hetzer, G. Stereocontrolled access to higher sugars (non-1-en-4-ulopyranosyl derivatives) and glycomimetics [3-(β-D-glycopyranosyl)-1-propenes and (3Z)-4,8-anhydro-nona-1,3-dienitols]. Eur. J. Org. Chem. 2000, 2000, 2831−2838. (143) Krishna, P. R.; Lavanya, B.; Jyothi, Y.; Sharma, G. V. M Radical mediated diastereoselective synthesis of benzothiazole sulfonyl ethyl Cglycosides. J. Carbohydr. Chem. 2003, 22, 423−431. (144) Pasquarello, C.; Picasso, S.; Demange, R.; Malissard, M.; Berger, E. G.; Vogel, P. The C-disaccharide α-C(1→3)-mannopyranoside of Nacetylgalactosamine is an inhibitor of glycohydrolases and of human α1,3-fucosyltransferase VI. Its epimer α-(1→3)-mannopyranoside of Nacetyltalosamine is not. J. Org. Chem. 2000, 65, 4251−4260. (145) Viode, C.; Vogel, P. Synthesis of the C-disaccharide α-C(1→3)L-fucopyranoside of N-acetylgalactosamine. J. Carbohydr. Chem. 2001, 20, 733−746. (146) Bouvet, V. R.; Ben, R. N. A short and economical synthesis of orthogonally protected C-linked 2-deoxy-2-acetamido-α-D-galactopyranose derivatives. J. Org. Chem. 2006, 71, 3619−3622. (147) Kancharla, P. K.; Navuluri, C.; Crich, D. Dissecting the influence of oxazolidinones and cyclic carbonates in sialic acid chemistry. Angew. Chem., Int. Ed. 2012, 51, 11105−11109. (148) Guindon, Y.; Bencheqroun, M.; Bouzide, A. Synthesis of postulated molecular probes: stereoselective free-radical-mediated Cglycosylation in tandem with hydrogen transfer. J. Am. Chem. Soc. 2005, 127, 554−558. (149) Vidal, S.; Bruyere, I.; Malleron, A.; Auge, C.; Praly, J.-P. Nonisosteric C-glycosyl analogues of natural nucleotide diphosphate sugars as glycosyltransferase inhibitors. Bioorg. Med. Chem. 2006, 14, 7293− 7301.

(150) Chen, G.-R.; Praly, J.-P. Free-radical and ionic routes towards hydrolytically stable and bioactive C-glycosyl compounds. C. R. Chim. 2008, 11, 19−28. (151) Readman, S. K.; Marsden, S. P.; Hodgson, A. Nickel-catalysed synthesis of C-glycosides and deoxysugars from glycosyl bromides. Synlett 2000, 2000, 1628−1630. (152) Juhasz, Z.; Micskei, K.; Gal, E.; Somsak, L. Chromium(II)complex mediated formation of C-glycosides from glycosyl halides under aqueous biphasic conditions. Tetrahedron Lett. 2007, 48, 7351− 7353. (153) Spencer, R. P.; Schwartz, J. Titanium(III) reagents in carbohydrate chemistry: glycal and C-glycoside synthesis. Tetrahedron 2000, 56, 2103−2112. (154) Caddick, S.; Hamza, D.; Judd, D. B.; Reich, M. T.; Wadman, S. N.; Wilden, J. D. A novel route to functionalized PFP esters via rapid intermolecular radical addition to PFP acrylate mediated by ethylpiperidinium hypophosphite (EPHP). Tetrahedron Lett. 2004, 45, 2363−2366. (155) Andrews, R. S.; Becker, J. J.; Gagne, M. R. A photoflow reactor for the continuous photoredox-mediated synthesis of C-glycoamino acids and C-glycolipids. Angew. Chem., Int. Ed. 2012, 51, 4140−4143. (156) Andrews, R. S.; Becker, J. J.; Gagne, M. R. Intermolecular addition of glycosyl halides to alkenes mediated by visible light. Angew. Chem., Int. Ed. 2010, 49, 7274−7276. (157) Gong, H.; Gagne, M. R. Diastereoselective Ni-catalyzed Negishi cross-coupling approach to saturated, fully oxygenated C-alkyl and Caryl glycosides. J. Am. Chem. Soc. 2008, 130, 12177−12183. (158) Gong, H.; Andrews, R. S.; Zuccarello, J. L.; Lee, S. J.; Gagne, M. R. Sn-free Ni-catalyzed reductive coupling of glycosyl bromides with activated alkenes. Org. Lett. 2009, 11, 879−882. (159) Zhao, C.; Jia, X.; Wang, X.; Gong, H. Ni-catalyzed reductive coupling of alkyl acids with unactivated tertiary alkyl and glycosyl halides. J. Am. Chem. Soc. 2014, 136, 17645−17651. (160) Breitenfeld, J.; Ruiz, J.; Wodrich, M. D.; Hu, X. Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl−alkyl Kumada coupling reactions. J. Am. Chem. Soc. 2013, 135, 12004−12012. (161) Biswas, S.; Weix, D. J. Mechanism and selectivity in nickelcatalyzed cross-electrophile coupling of aryl halides with alkyl halides. J. Am. Chem. Soc. 2013, 135, 16192−16197. (162) Zuo, Z.; Ahneman, D. T.; Chu, L.; Terrett, J. A.; Doyle, A. G.; MacMillan, D. W. C. Merging photoredox with nickel catalysis: coupling of α-carboxyl sp3-carbons with aryl halides. Science 2014, 345, 437−440. (163) Schley, N. D.; Fu, G. C. Nickel-catalyzed Negishi arylations of propargylic bromides: a mechanistic investigation. J. Am. Chem. Soc. 2014, 136, 16588−16593. (164) Jia, X.; Zhang, X.; Qian, Q.; Gong, H. Alkyl−aryl ketone synthesis via nickel-catalyzed reductive coupling of alkyl halides with aryl acids and anhydrides. Chem. Commun. 2015, 51, 10302−10305. (165) Nicolas, L.; Angibaud, P.; Stansfield, I.; Bonnet, P.; Meerpoel, L.; Reymond, S.; Cossy, J. Diastereoselective metal-catalyzed synthesis of C-aryl and C-vinyl glycosides. Angew. Chem., Int. Ed. 2012, 51, 11101− 11104. (166) Nicolas, L.; Izquierdo, E.; Angibaud, P.; Stansfield, I.; Meerpoel, L.; Reymond, S.; Cossy, J. Cobalt-catalyzed diastereoselective synthesis of C-furanosides. Total synthesis of (−)-isoaltholactone. J. Org. Chem. 2013, 78, 11807−11814. (167) Dawe, R. D.; Fraser-Reid, B. α-C-Glycopyranosides from Lewis acid catalysed condensations of acetylated glycals and enol silanes. J. Chem. Soc., Chem. Commun. 1981, 1180−1181. (168) Ansari, A. A.; Lahiri, R.; Vankar, Y. D. The carbon-Ferrier rearrangement: an approach towards the synthesis of C-glycosides. ARKIVOC 2013, 2013 (ii), 316−362. (169) Schmidt, R. R.; Vankar, Y. D. 2-Nitroglycals as powerful glycosyl donors: application in the synthesis of biologically important molecules. Acc. Chem. Res. 2008, 41, 1059−1073. (170) Czernecki, S.; Gruy, F. Nouvelle voie d’acces aux C-glycosides. Tetrahedron Lett. 1981, 22, 437−440. 12341


Chemical Reviews

Review

(192) Levecque, P.; Gammon, D. W.; Jacobs, P.; De Vos, D.; Sels, B. The use of ultrastable Y zeolites in the Ferrier rearrangement of acetylated and benzylated glycals. Green Chem. 2010, 12, 828−835. (193) Rotella, M.; Giovine, M.; Dougherty, W., Jr.; Boyko, W.; Kassel, S.; Giuliano, R. Synthesis and x-ray crystallographic analysis of 4,6-di-Oacetyl-2,3-dideoxy-α-D-threo-hexopyranosyl cyanide. Carbohydr. Res. 2016, 425, 40−42. (194) Yadav, J. S.; Satyanarayana, M.; Balanarsaiah, E.; Raghavendra, S. Phosphomolybdic acid supported on silica gel: a mild, efficient and reusable catalyst for the synthesis of 2,3-unsaturated glycopyranosides by Ferrier rearrangement. Tetrahedron Lett. 2006, 47, 6095−6098. (195) Ghosh, R.; Chakraborty, A.; Maiti, S. Synergistic enhancement of catalytic activity of InCl3-Me3SiCl combination towards carbon Ferrier rearrangement in glycal derivatives. ARKIVOC 2004, 2004 (xiv), 1−9. (196) Yeager, A. R.; Min, G. K.; Porco, J. A., Jr.; Schaus, S. E. Exploring skeletal diversity via ring contraction of glycal-derived scaffolds. Org. Lett. 2006, 8, 5065−5068. (197) Stevanovic, D.; Pejovic, A.; Damljanovic, I.; Minic, A.; Bogdanovic, G. A.; Vukicevic, M.; Radulovic, N. S.; Vukicevic, R. D. Ferrier rearrangement promoted by an electrochemically generated zirconium catalyst. Carbohydr. Res. 2015, 407, 111−121. (198) Gerard, B.; Marie, J.-C.; Pandya, B. A.; Lee, M. D., IV; Liu, H.; Marcaurelle, L. A. Large-scale synthesis of all stereoisomers of a 2,3unsaturated C-glycoside scaffold. J. Org. Chem. 2011, 76, 1898−1901. (199) Berber, H.; Brigaud, T.; Lefebvre, O.; Plantier-Royon, R.; Portella, C. Reactions of difluoroenoxysilanes with glycosyl donors: synthesis of difluoro-C-glycosides and difluoro-C-disaccharides. Chem. Eur. J. 2001, 7, 903−909. (200) Poulain, F.; Serre, A.-L.; Lalot, J.; Leclerc, E.; Quirion, J.-C. Synthesis of α-CF2-mannosides and their conversion to fluorinated pseudoglycopeptides. J. Org. Chem. 2008, 73, 2435−2438. (201) Portella, C.; Brigaud, T.; Lefebvre, O.; Plantier-Royon, R. Convergent synthesis of fluoro and gem-difluoro compounds using trifluoromethyltrimethylsilane. J. Fluorine Chem. 2000, 101, 193−198. (202) Di Bussolo, V.; Caselli, M.; Romano, M. R.; Pineschi, M.; Crotti, P. Stereospecific uncatalyzed α-O-glycosylation and α-C-glycosidation by means of a new D-gulal-derived α vinyl oxirane. J. Org. Chem. 2004, 69, 7383−7386. (203) Di Bussolo, V.; Caselli, M.; Pineschi, M.; Crotti, P. New stereoselective β-C-glycosidation by uncatalyzed 1,4-addition of organolithium reagents to a glycal-derived vinyl oxirane. Org. Lett. 2003, 5, 2173−2176. (204) Deelertpaiboon, P.; Reutrakul, V.; Jarussophon, S.; Tuchinda, P.; Kuhakarn, C.; Pohmakotr, M. Efficient synthesis of alkyl 2,3-unsaturated glucopyranosides from glycals mediated by ytterbium(III) triflate− trialkyl aluminum. Tetrahedron Lett. 2009, 50, 6233−6235. (205) Steinhuebel, D. P.; Fleming, J. J.; Du Bois, J. Stereoselective organozinc addition reactions to 1,2-dihydropyrans for the assembly of complex pyran structures. Org. Lett. 2002, 4, 293−295. (206) Cook, M. J.; Fletcher, M. J. E.; Gray, D.; Lovell, P. J.; Gallagher, T. Highly stereoselective addition of organozinc reagents to pentopyranose derived glycals: effect of protecting group and assignment of C-glycoside stereochemistry. Tetrahedron 2004, 60, 5085−5092. (207) Vieira, A. S.; Fiorante, P. F.; Hough, T. L. S.; Ferreira, F. P.; Lüdtke, D. S.; Stefani, H. A. Nucleophilic addition of potassium alkynyltrifluoroborates to D-glucal mediated by BF3·OEt2: highly stereoselective synthesis of α-C-glycosides. Org. Lett. 2008, 10, 5215− 5218. (208) Stefani, H. A.; Silva, N. C. S.; Manarin, F.; Lüdtke, D. S.; Zukerman-Schpector, J.; Madureira, L. S.; Tiekink, E. R. T. Synthesis of 1,2,3-triazolylpyranosides through click chemistry reaction. Tetrahedron Lett. 2012, 53, 1742−1747. (209) Lubin-Germain, N.; Hallonet, A.; Huguenot, F.; Palmier, S.; Uziel, J.; Auge, J. Ferrier-type alkynylation reaction mediated by indium. Org. Lett. 2007, 9, 3679−3682. (210) Ayed, C.; Palmier, S.; Lubin-Germain, N.; Uziel, J.; Auge, J. Indium-mediated alkynylation of sugars: synthesis of C-glycosyl

(171) Nicolaou, K. C.; Hwang, C.-K.; Duggan, M. E. Stereospecific synthesis of 1,1-dialkylglycosides. J. Chem. Soc., Chem. Commun. 1986, 925−926. (172) Hanessian, S.; Martin, M.; Desai, R. C. Formation of Cglycosides by polarity inversion at the anomeric centre. J. Chem. Soc., Chem. Commun. 1986, 926−927. (173) Moreno, B.; Quehen, C.; Rose-Helene, M.; Leclerc, E.; Quirion, J.-C. Addition of difluoromethyl radicals to glycals: a new route to αCF2-D-glycosides. Org. Lett. 2007, 9, 2477−2480. (174) Takhi, M.; Abdel Rahman, A. A.-H.; Schmidt, R. R. Yb(OTf)3catalyzed C-glycosylation: highly stereoselective synthesis of Cpseudoglycals. Tetrahedron Lett. 2001, 42, 4053−4056. (175) Anjaiah, S.; Chandrasekhar, S.; Gree, R. Carbon-Ferrier rearrangements in ionic liquids using Yb(OTf)3 as catalyst. J. Mol. Catal. A: Chem. 2004, 214, 133−136. (176) Yadav, J. S.; Reddy, B. V. S.; Rao, C. V.; Chand, P. K.; Prasad, A. R. Iodine-catalyzed stereoselective synthesis of allylglycosides, glycosyl cyanides and glycosyl azides. Synlett 2001, 2001, 1638−1640. (177) Saeeng, R.; Sirion, U.; Sahakitpichan, P.; Isobe, M. Iodine catalyzes C-glycosidation of D-glucal with silylacetylene. Tetrahedron Lett. 2003, 44, 6211−6215. (178) Das, S. K.; Reddy, K. A.; Abbineni, C.; Roy, J.; Rao, K. V. L. N.; Sachwani, R. H.; Iqbal, J. Microwave-induced, InCl3-catalyzed Ferrier rearrangement of acetylglycals: synthesis of 2,3-unsaturated C-glycosides. Tetrahedron Lett. 2003, 44, 4507−4509. (179) Yadav, J. S.; Reddy, B. V. S.; Raju, K.; Rao, C. V. Indium tribromide-catalyzed highly stereoselective synthesis of alkynylsugars. Tetrahedron Lett. 2002, 43, 5437−5440. (180) Yadav, J. S.; Reddy, B. V. S.; Srinivasa Reddy, K.; Chandraiah, L.; Sunitha, V. Bi(OTf)3 as novel and efficient catalyst for the stereoselective synthesis of C-pseudoglycals. Synthesis 2004, 2004, 2523− 2526. (181) Chen, P.; Bi, B. Preparation of 2,3-unsaturated pseudoglycosides with Ferrier rearrangement promoted by Tm(OTf)3 as a highly efficient catalyst. Tetrahedron Lett. 2015, 56, 4895−4899. (182) Chen, P.; Su, J. Gd(OTf)3 catalyzed preparation of 2,3unsaturated O-, S-, N-, and C-pyranosides from glycals by Ferrier rearrangement. Tetrahedron 2016, 72, 84−94. (183) Tiwari, P.; Agnihotri, G.; Misra, A. K. Synthesis of 2,3unsaturated C-glycosides by HClO4−SiO2 catalyzed Ferrier rearrangement of glycals. Carbohydr. Res. 2005, 340, 749−752. (184) Ansari, A. A.; Reddy, Y. S.; Vankar, Y. D. Efficient carbon-Ferrier rearrangement on glycals mediated by ceric ammonium nitrate: application to the synthesis of 2-deoxy-2-amino-C-glycoside. Beilstein J. Org. Chem. 2014, 10, 300−306. (185) Reddy, T. R.; Rao, D. S.; Kashyap, S. A mild and efficient Zncatalyzed C-glycosylation: synthesis of C(2)−C(3) unsaturated Clinked glycopyranosides. RSC Adv. 2015, 5, 28338−28343. (186) Srinivas, B.; Reddy, T. R.; Kashyap, S. Ruthenium catalyzed synthesis of 2,3-unsaturated C-glycosides from glycals. Carbohydr. Res. 2015, 406, 86−92. (187) Balamurugan, R.; Koppolu, S. R. Scope of AuCl3 in the activation of per-O-acetylglycals. Tetrahedron 2009, 65, 8139−8142. (188) Abdel-Rahman, A. A.-H.; Takhi, M.; El Ashry, E. S. H.; Schmidt, R. R. Stereoselective synthesis of pseudoglycal C-glycosides via trichloroacetimidate activation of glycals. J. Carbohydr. Chem. 2002, 21, 113−122. (189) Ghosh, R.; Chakraborty, A.; Maiti, D. K. In(OTf)3a new efficient Lewis acid catalyst for stereoselective C-glycosylation reactions of glycal derivatives. Synth. Commun. 2003, 33, 1623−1632. (190) Yadav, J. S.; Reddy, B. V. S.; Chand, P. K. Sc(OTf)3-catalyzed Cglycosidation of glycals: a facile synthesis of allyl glycosides, glycosyl cyanides and glycosyl azides. Tetrahedron Lett. 2001, 42, 4057−4059. (191) Yadav, J. S.; Reddy, B. V. S.; Chandraiah, L.; Reddy, K. S. LiBF4mediated C-glycosylation of glycals with allyltrimethylsilane: a facile synthesis of allyl C-glycosylic compounds. Carbohydr. Res. 2001, 332, 221−224. 12342


Chemical Reviews

Review

compounds bearing a protected amino alcohol moiety. Carbohydr. Res. 2010, 345, 2566−2570. (211) Ayed, C.; Picard, J.; Lubin-Germain, N.; Uziel, J.; Auge, J. Synthesis of alkynes and alkynyl iodides bearing a protected amino alcohol moiety as functionalized amino acids precursors. Sci. China: Chem. 2010, 53, 1921−1926. (212) Price, S.; Edwards, S.; Wu, T.; Minehan, T. Synthesis of C-arylΔ2,3-glycopyranosides via uncatalyzed addition of triarylindium reagents to glycals. Tetrahedron Lett. 2004, 45, 5197−5201. (213) Devari, S.; Kumar, M.; Deshidi, R.; Rizvi, M.; Shah, B. A. A general metal-free approach for the stereoselective synthesis of C-glycals from unactivated alkynes. Beilstein J. Org. Chem. 2014, 10, 2649−2653. (214) Wieczorek, E.; Thiem, J. Formation of C-glycosides by Ferrier reaction. J. Carbohydr. Chem. 2013, 32, 502−512. (215) Chen, H.; Luo, X.; Qiu, S.; Sun, W.; Zhang, J. TMSOTf mediated stereoselective synthesis of α-C-glycosides from unactivated aryl acetylenes. Glycoconjugate J. 2017, 34, 13−20. (216) Tatina, M. B.; Kusunuru, A. K.; Yousuf, S. K.; Mukherjee, D. Zinc mediated activation of terminal alkynes: stereoselective synthesis of alkynyl glycosides. Org. Biomol. Chem. 2014, 12, 7900−7903. (217) Kusunuru, A. K.; Tatina, M.; Yousuf, S. K.; Mukherjee, D. Copper mediated stereoselective synthesis of C-glycosides from unactivated alkynes. Chem. Commun. 2013, 49, 10154−10156. (218) Hosseyni, S.; Smith, C. A.; Shi, X. Gold-catalyzed vinyl ether hydroalkynylation: an alternative pathway for the gold-catalyzed intermolecular reaction of alkenes and alkynes. Org. Lett. 2016, 18, 6336−6339. (219) Yadav, J. S.; Reddy, B. V. S.; Raman, J. V.; Niranjan, N.; Kiran Kumar, S.; Kunwar, A. C. InCl3-catalyzed stereoselective synthesis of Cglycosyl heteroaromatics. Tetrahedron Lett. 2002, 43, 2095−2098. (220) Tan, H. Y.; Xiang, S.; Leng, W. L.; Liu, X.-W. Regio and stereoselective synthesis of β-keto functionalized C-glycosides via iron catalyzed Ferrier rearrangement reactions. RSC Adv. 2014, 4, 34816− 34822. (221) Yadav, J. S.; Reddy, B. V. S.; Narasimha Chary, D.; Madavi, C.; Kunwar, A. C. First example of the carbon-Ferrier rearrangement of glycals with isocyanides: a novel synthesis of C-glycosyl amides. Tetrahedron Lett. 2009, 50, 81−84. (222) Dash, A. K.; Madhubabu, T.; Yousuf, S. K.; Raina, S.; Mukherjee, D. One-pot Mukaiyama type carbon-Ferrier rearrangement of glycals: application in the synthesis of chromanone 3-C-glycosides. Carbohydr. Res. 2017, 438, 1−8. (223) Larrosa, I.; Romea, P.; Urpi, F.; Balsells, D.; Vilarrasa, J.; FontBardia, M.; Solans, X. Unprecedented highly stereoselective a- and β-Cglycosidation with chiral titanium enolates. Org. Lett. 2002, 4, 4651− 4654. (224) Galvez, E.; Larrosa, I.; Romea, P.; Urpi, F. Stereoselective synthesis of a- and β-C-glycosides by addition of titanium enolates to glycals. Synlett 2009, 2009, 2982−2986. (225) Galvez, E.; Sau, M.; Romea, P.; Urpi, F.; Font-Bardia, M. Stereoselective synthesis of C-glycosides by addition of titanium enolates from a chiral N-glycolyl thiazolidinethione to glycals. Tetrahedron Lett. 2013, 54, 1467−1470. (226) Reddy, G. M.; Maheswara Rao, B. U.; Sridhar, P. R. Stereoselective synthesis of 2-(β-C-glycosyl)glycals: access to unusual β-C-glycosides from 3-deoxyglycals. J. Org. Chem. 2016, 81, 2782−2793. (227) Yadav, J. S.; Reddy, B. V. S.; Rao, K. V.; Saritha Raj, K.; Prasad, A. R.; Kiran Kumar, S.; Kunwar, A. C.; Jayaprakash, P.; Jagannath, B. InBr3catalyzed cyclization of glycals with aryl amines. Angew. Chem., Int. Ed. 2003, 42, 5198−5201. (228) Du, C.; Li, F.; Zhang, X.; Hu, W.; Yao, Q.; Zhang, A. Lewis acid catalyzed cyclization of glycals/2-deoxy-D-ribose with arylamines: additional findings on product structure and reaction diastereoselectivity. J. Org. Chem. 2011, 76, 8833−8839. (229) Pachamuthu, K.; Gupta, A.; Das, J.; Schmidt, R. R.; Vankar, Y. D. An easy route to 2-amino-β-C-glycosides by conjugate addition to 2nitroglycals. Eur. J. Org. Chem. 2002, 2002, 1479−1483.

(230) Zhang, T.; Yu, C.-Y.; Huang, Z.-T.; Jia, Y.-M. Solvent-free and stereoselective synthesis of C-glycosides by Michael-type addition of enamino esters to 2-nitro-D-glucal. Synlett 2010, 2010, 2174−2178. (231) Reddy, B. G.; Vankar, Y. D. The synthesis of hybrids of Dgalactose with 1-deoxynojirimycin analogues as glycosidase inhibitors. Angew. Chem., Int. Ed. 2005, 44, 2001−2004. (232) Aydillo, C.; Navo, C. D.; Busto, J. H.; Corzana, F.; Zurbano, M. M.; Avenoza, A.; Peregrina, J. M. A double diastereoselective Michaeltype addition as an entry to conformationally restricted Tn antigen mimics. J. Org. Chem. 2013, 78, 10968−10977. (233) Delaunay, T.; Poisson, T.; Jubault, P.; Pannecoucke, X. Stereoselective access to β-C-glycosamines by nitro-Michael addition of organolithium reagents. Eur. J. Org. Chem. 2014, 2014, 3341−3345. (234) Cai, S.; Xiang, S.; Zeng, J.; Gorityala, B. K.; Liu, X.-W. Facile synthesis of carbohydrate-integrated isoxazolines through tandem [4 + 1] cycloaddition and rearrangement of 2-nitroglycals. Chem. Commun. 2011, 47, 8676−8678. (235) Hayashi, M.; Nakayama, S.-z.; Kawabata, H. HF−pyridine promoted Friedel−Crafts type arylation of 2-acetoxy-D-glucal. Stereoselective synthesis of 1-arylhex-3-enopyranosiduloses. Chem. Commun. 2000, 1329−1330. (236) Gupta, P.; Kumari, N.; Agarwal, A.; Vankar, Y. D. HClO4·SiO2 catalysed synthesis of alkyl 3-deoxy-hex-2-enopyranosides from 2hydroxy glucal ester: application in the synthesis of a cis-fused bicyclic ether and a 4-amino-C-glucoside. Org. Biomol. Chem. 2008, 6, 3948− 3956. (237) Leonelli, F.; Capuzzi, M.; Calcagno, V.; Passacantilli, P.; Piancatelli, G. Stereoselective Michael-type addition of organocopper reagents to enones derived from glycals in the synthesis of 2-phosphonoα-C-glycosides. Eur. J. Org. Chem. 2005, 2005, 2671−2676. (238) Parker, K. A.; Mindt, T. L.; Koh, Y.-h. TESOTf-induced rearrangement of quinols. Efficient construction of the fully functionalized carbon skeleton of the griseusins by a divergent-reconvergent approach. Org. Lett. 2006, 8, 1759−1762. (239) Parker, K. A.; Su, D.-S. The “reverse polarity” approach to ravidomycin. Aryl C-aminoglycosides from a lithiated aminoglycal. J. Carbohydr. Chem. 2005, 24, 187−197. (240) Dötz, K. H.; Jäkel, C.; Haase, W.-C. Metal glycosylidenes: novel organometallic tools for C-glycosidation. Part 19. Organotransition metal modified sugars. J. Organomet. Chem. 2001, 617−618, 119−132. (241) Dötz, K. H.; Otto, F.; Nieger, M. Organotransition-metalmodified sugars. Part 17. Glucal-derived carbene complexes: synthesis and diastereoselective benzannulation. J. Organomet. Chem. 2001, 621, 77−88. (242) Jäkel, C.; Dötz, K. H. From glycals to metal pyranosylidenes: diastereoselective addition of electrophiles to metal carbene enolate intermediates. Tetrahedron 2000, 56, 2167−2173. (243) Le, T. X.; Papin, C.; Doisneau, G.; Beau, J.-M. Direct umpolung of glycals and related 2,3-unsaturated N-acetylneuraminic acid derivatives using samarium diiodide. Angew. Chem., Int. Ed. 2014, 53, 6184−6187. (244) Lopez, J. C.; Fraser-Reid, B. Serial radical reactions of enol ethers: ready routes to highly functionalized C-glycosyl derivatives. J. Am. Chem. Soc. 1989, 111, 3450−3452. (245) Gomez, A. M.; Casillas, M.; Valverde, S.; Lopez, J. C. Stereocontrolled entry to β-C-glycosides and bis-C,C-glycosides from C-glycals: preparation of a highly functionalized triene from D-mannose. Tetrahedron: Asymmetry 2001, 12, 2175−2183. (246) Colombel, S.; Van Hijfte, N.; Poisson, T.; Leclerc, E.; Pannecoucke, X. Addition of electrophilic radicals to 2-benzyloxyglycals: synthesis and functionalization of fluorinated α-C-glycosides and derivatives. Chem. - Eur. J. 2013, 19, 12778−12787. (247) Hutter, D.; Benner, S. A. Expanding the genetic alphabet: nonepimerizing nucleoside with the pyDDA hydrogen-bonding pattern. J. Org. Chem. 2003, 68, 9839−9842. (248) Liu, H.; Gao, J.; Maynard, L.; Saito, Y. D.; Kool, E. T. Toward a new genetic system with expanded dimensions: size-expanded analogues of deoxyadenosine and thymidine. J. Am. Chem. Soc. 2004, 126, 1102−1109. 12343


Chemical Reviews

Review

strate-controlled synthesis of C-vinyl glycosides. Org. Lett. 2017, 19, 416−419. (270) Ramnauth, J.; Poulin, O.; Bratovanov, S. S.; Rakhit, S.; Maddaford, S. P. Stereoselective C-glycoside formation by a rhodium(I)-catalyzed 1,4-addition of arylboronic acids to acetylated enones derived from glycals. Org. Lett. 2001, 3, 2571−2573. (271) Bertini, B.; Moineau, C.; Sinou, D.; Gesekus, G.; Vill, V. Stereospecific synthesis of new trioxadecalin-derived liquid crystals bearing halogen substituents on the phenyl ring. Eur. J. Org. Chem. 2001, 2001, 375−381. (272) Kaelin, D. E., Jr.; Lopez, O. D.; Martin, S. F. General strategies for the synthesis of the major classes of C-aryl glycosides. J. Am. Chem. Soc. 2001, 123, 6937−6938. (273) Koester, D. C.; Leibeling, M.; Neufeld, R.; Werz, D. B. A Pdcatalyzed approach to (1→6)-linked C-glycosides. Org. Lett. 2010, 12, 3934−3937. (274) Xue, X.; Li, W.; Yin, Z.; Meng, X.; Li, Z. Concise and direct construction of cis-pyrano[4,3-b]pyran-5-one skeleton from glucal derivatives: synthesis of ent-4-deoxy-2,3-di-epi-dinemasone BC. Tetrahedron Lett. 2015, 56, 5228−5230. (275) Liu, M.; Niu, Y.; Wu, Y.-F.; Ye, X.-S. Ligand-controlled monoselective C-aryl glycoside synthesis via palladium-catalyzed C−H functionalization of N-quinolyl benzamides with 1-iodoglycals. Org. Lett. 2016, 18, 1836−1839. (276) Zhang, S.; Niu, Y.; Ye, X.-S. General approach to five-membered nitrogen heteroaryl C-glycosides using a palladium/copper cocatalyzed C−H functionalization strategy. Org. Lett. 2017, 19, 3608−3611. (277) Potuzak, J. S.; Tan, D. S. Synthesis of C1-alkyl- and acylglycals from glycals using a B-alkyl Suzuki−Miyaura cross coupling approach. Tetrahedron Lett. 2004, 45, 1797−1801. (278) Kikuchi, T.; Takagi, J.; Isou, H.; Ishiyama, T.; Miyaura, N. Vinylic C−H borylation of cyclic vinyl ethers with bis(pinacolato)diboron catalyzed by an iridium(I)-dtbpy complex. Chem. - Asian J. 2008, 3, 2082−2090. (279) Oroszova, B.; Choutka, J.; Pohl, R.; Parkan, K. Modular stereoselective synthesis of (1→2)-C-glycosides based on the sp2−sp3 Suzuki−Miyaura reaction. Chem. - Eur. J. 2015, 21, 7043−7047. (280) Pedzisa, L.; Vaughn, I. W.; Pongdee, R. Suzuki−Miyaura crosscoupling of α-phosphoryloxy enol ethers with arylboronic acids. Tetrahedron Lett. 2008, 49, 4142−4144. (281) Koo, B.; McDonald, F. E. Synthesis of the branched C-glycoside substructure of altromycin B. Org. Lett. 2005, 7, 3621−3624. (282) Hartung, J.; Wright, B. J. D.; Danishefsky, S. J. Studies toward the total synthesis of pluraflavin A. Chem. - Eur. J. 2014, 20, 8731−8736. (283) Khatri, H. R.; Nguyen, H.; Dunaway, J. K.; Zhu, J. Total synthesis of antitumor antibiotic derhodinosylurdamycin A. Chem. - Eur. J. 2015, 21, 13553−13557. (284) Gunn, A.; Jarowicki, K.; Kocienski, P.; Lockhart, S. The preparation of 1-tributylstannyl glycals from 1-phenylsulfonyl glycals via Ni(0)-catalysed coupling with tributylstannylmagnesium bromide. Synthesis 2001, 2001, 331−338. (285) Koester, D. C.; Kriemen, E.; Werz, D. B. Flexible synthesis of 2deoxy-C-glycosides and (1→2)-, (1→3)-, and (1→4)-linked Cglycosides. Angew. Chem., Int. Ed. 2013, 52, 2985−2989. (286) Reddy Dubbaka, S.; Steunenberg, P.; Vogel, P. Aryl and arylmethyl C-glycosides through desulfitative Stille and carbonylative Stille cross-coupling of tinglycals and sulfonyl chlorides. Synlett 2004, 1235−1238. (287) Steunenberg, P.; Jeanneret, V.; Zhu, Y.-H.; Vogel, P. C(1→4)linked disaccharides through carbonylative Stille cross-coupling. Tetrahedron: Asymmetry 2005, 16, 337−346. (288) Boucard, V.; Larrieu, K.; Lubin-Germain, N.; Uziel, J.; Auge, J. CGlycosylated phenylalanine synthesis by palladium-catalyzed crosscoupling reactions. Synlett 2003, 1834−1837. (289) Ousmer, M.; Boucard, V.; Lubin-Germain, N.; Uziel, J.; Auge, J. Gram-scale preparation of a p-(C-glucopyranosyl)-L-phenylalanine derivative by a Negishi cross-coupling reaction. Eur. J. Org. Chem. 2006, 2006, 1216−1221.

(249) Li, J.-S.; Fan, Y.-H.; Zhang, Y.; Marky, L. A.; Gold, B. Design of triple helix forming C-glycoside molecules. J. Am. Chem. Soc. 2003, 125, 2084−2093. (250) Wang, Z.-X.; Wiebe, L. I.; Balzarini, J.; De Clercq, E.; Knaus, E. E. Chiral synthesis of 4-[1-(2-deoxy-β-L-ribofuranosyl)] derivatives of 2substituted 5-fluoroaniline: “cytosine replacement” analogues of deoxyβ-L-cytidine. J. Org. Chem. 2000, 65, 9214−9219. (251) Coleman, R. S.; Berg, M. A.; Murphy, C. J. Coumarin base-pair replacement as a fluorescent probe of ultrafast DNA dynamics. Tetrahedron 2007, 63, 3450−3456. (252) Kim, H.-J.; Leal, N. A.; Benner, S. A. 2′-Deoxy-1methylpseudocytidine, a stable analog of 2′-deoxy-5-methylisocytidine. Bioorg. Med. Chem. 2009, 17, 3728−3732. (253) Gudmundsson, K. S.; Williams, J. D.; Drach, J. C.; Townsend, L. B. Synthesis and antiviral activity of novel erythrofuranosyl imidazo[1,2a]pyridine C-nucleosides constructed via palladium coupling of iodoimidazo[1,2-a]pyridines and dihydrofuran. J. Med. Chem. 2003, 46, 1449−1455. (254) Lee, A. H. F.; Kool, E. T. Novel benzopyrimidines as widened analogues of DNA bases. J. Org. Chem. 2005, 70, 132−140. (255) Tao, Y.; Ding, N.; Ren, S.; Li, Y. Heck-type cross-coupling between halo-exo-glycals and endo-glycals: a practical way to achieve Cglycosidic disaccharides. Tetrahedron Lett. 2013, 54, 6101−6104. (256) Li, H.-H.; Ye, X.-S. Regio- and stereo-selective synthesis of aryl 2deoxy-C-glycopyranosides by palladium-catalyzed Heck coupling reactions of glycals and aryl iodides. Org. Biomol. Chem. 2009, 7, 3855−3861. (257) Lei, M.; Gao, L.; Yang, J.-S. Microwave-assisted palladiumcatalyzed cross-coupling reactions between pyranoid glycals and aryl bromides. Synthesis of 2′-deoxy C-aryl-β-glycopyranosides. Tetrahedron Lett. 2009, 50, 5135−5138. (258) Ramnauth, J.; Poulin, O.; Rakhit, S.; Maddaford, S. P. Palladium(II) acetate catalyzed stereoselective C-glycosylation of peracetylated glycals with arylboronic acids. Org. Lett. 2001, 3, 2013− 2015. (259) Xiong, D.-C.; Zhang, L.-H.; Ye, X.-S. Oxidant-controlled Hecktype C-glycosylation of glycals with arylboronic acids: stereoselective synthesis of aryl 2-deoxy-C-glycosides. Org. Lett. 2009, 11, 1709−1712. (260) Kusunuru, A. K.; Jaladanki, C. K.; Tatina, M. B.; Bharatam, P. V.; Mukherjee, D. TEMPO-promoted domino Heck−Suzuki arylation: diastereoselective cis-diarylation of glycals and pseudoglycals. Org. Lett. 2015, 17, 3742−3745. (261) Bai, Y.; Leng, W. L.; Li, Y.; Liu, X.-W. A highly efficient dual catalysis approach for C-glycosylation: addition of (o-azaaryl)carboxaldehyde to glycals. Chem. Commun. 2014, 50, 13391−13393. (262) Bai, Y.; Kim, L. M. H.; Liao, H.; Liu, X.-W. Oxidative Heck reaction of glycals and aryl hydrazines: a palladium-catalyzed Cglycosylation. J. Org. Chem. 2013, 78, 8821−8825. (263) Xiang, S.; Cai, S.; Zeng, J.; Liu, X.-W. Regio- and stereoselective synthesis of 2-deoxy-C-aryl glycosides via palladium catalyzed decarboxylative reactions. Org. Lett. 2011, 13, 4608−4611. (264) Ma, J.; Xiang, S.; Jiang, H.; Liu, X.-W. Palladium-catalyzed stereoselective C-glycosylation of glycals with sodium arylsulfinates. Eur. J. Org. Chem. 2015, 2015, 949−952. (265) Xu, X.; Tan, Q.; Hayashi, M. Versatile and mild synthesis of diand trisaccharidic 2-enopyranosyl cyanides by cyanation of per-Oacetylglycals with trimethylsilyl cyanide catalyzed by palladium(II) acetate. Synthesis 2008, 2008, 770−776. (266) Gupta, A.; Vankar, Y. D. Synthesis of C-2 methylene O- and Cglycosides and sugar derived α-methylene-δ-valerolactones from C-2acetoxymethyl glycals. Tetrahedron 2000, 56, 8525−8531. (267) Leibeling, M.; Werz, D. B. Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions. Beilstein J. Org. Chem. 2013, 9, 2194−2201. (268) Zeng, J.; Ma, J.; Xiang, S.; Cai, S.; Liu, X.-W. Stereoselective β-Cglycosylation by a palladium-catalyzed decarboxylative allylation: formal synthesis of aspergillide A. Angew. Chem., Int. Ed. 2013, 52, 5134−5137. (269) Leng, W.-L.; Liao, H.; Yao, H.; Ang, Z.-E.; Xiang, S.; Liu, X.-W. Palladium-catalyzed decarboxylative allylation/Wittig Reaction: sub12344


Chemical Reviews

Review

(310) Lucero, C. G.; Woerpel, K. A. Stereoselective C-glycosylation reactions of pyranoses: the conformational preference and reactions of the mannosyl cation. J. Org. Chem. 2006, 71, 2641−2647. (311) Chang, G. X.; Lowary, T. L. An olefin cross metathesis approach to C-disaccharide analogs of the α-D-arabinofuranosyl-(1→5)-α-Darabinofuranoside motif found in the mycobacterial cell wall. Tetrahedron Lett. 2006, 47, 4561−4564. (312) Otero Martinez, H.; Reinke, H.; Michalik, D.; Vogel, C. Peracetylated β-allyl C-glycosides of D-ribofuranose and 2-deoxy-Dribofuranose in the chemical literature: until now, mirages in the literature. Synthesis 2009, 2009, 1834−1840. (313) Wächtler, H.; Fuentes, D. P.; Michalik, D.; Köckerling, M.; Villinger, A.; Kragl, U.; Cedeno, Q. A.; Vogel, C. A versatile approach to alcohol, aldehyde, ketone and amine derivatives starting from β-allyl Cglycosides of D-ribofuranose and 2-deoxy-D-ribofuranose. Synthesis 2011, 2011, 3099−3108. (314) Tran, V. T.; Woerpel, K. A. Nucleophilic addition to silylprotected five-membered ring oxocarbenium ions governed by stereoelectronic effects. J. Org. Chem. 2013, 78, 6609−6621. (315) Beaver, M. G.; Billings, S. B.; Woerpel, K. A. C-Glycosylation reactions of sulfur-substituted glycosyl donors: evidence against the role of neighboring-group participation. J. Am. Chem. Soc. 2008, 130, 2082− 2086. (316) Kendale, J. C.; Valentin, E. M.; Woerpel, K. A. Solvents effects in the nucleophilic substitutions of tetrahydropyran acetals promoted by trimethylsilyl trifluoromethanesulfonate: trichloroethylene as solvent for stereoselective C- and O-glycosylations. Org. Lett. 2014, 16, 3684− 3687. (317) Romero, J. A. C.; Tabacco, S. A.; Woerpel, K. A. Stereochemical reversal of nucleophilic substitution reactions depending upon substituent: reactions of heteroatom-substituted six-membered-ring oxocarbenium ions through pseudoaxial conformers. J. Am. Chem. Soc. 2000, 122, 168−169. (318) Ayala, L.; Lucero, C. G.; Romero, J. A. C.; Tabacco, S. A.; Woerpel, K. A. Stereochemistry of nucleophilic substitution reactions depending upon substituent: evidence for electrostatic stabilization of pseudoaxial conformers of oxocarbenium ions by heteroatom substituents. J. Am. Chem. Soc. 2003, 125, 15521−15528. (319) Krumper, J. R.; Salamant, W. A.; Woerpel, K. A. Correlations between nucleophilicities and selectivities in the substitutions of tetrahydropyran acetals. J. Org. Chem. 2009, 74, 8039−8050. (320) Dondoni, A.; Mariotti, G.; Marra, A. Synthesis of α- and βglycosyl asparagine ethylene isosteres (C-glycosyl asparagines) via sugar acetylenes and garner aldehyde coupling. J. Org. Chem. 2002, 67, 4475− 4486. (321) Wiebe, C.; Fuste de la Sotilla, S.; Opatz, T. Synthesis of 1,3- and 2,3-diglycosylated indoles as potential trisaccharide mimetics. Synthesis 2012, 44, 1385−1397. (322) Kolympadi, M.; Fontanella, M.; Venturi, C.; Andre, S.; Gabius, H.-J.; Jimenez-Barbero, J.; Vogel, P. Synthesis and conformational analysis of (α-D-galactosyl)phenylmethane and α-,β-difluoromethane analogues: interactions with the plant lectin viscumin. Chem. - Eur. J. 2009, 15, 2861−2873. (323) Toba, T.; Murata, K.; Yamamura, T.; Miyake, S.; Annoura, H. A concise synthesis of (3S,4S,5R)-1-(α-D-galactopyranosyl)-3-tetracosanoylamino-4,5-decanediol, a C-glycoside analogue of immunomodulating α-galactosylceramide OCH. Tetrahedron Lett. 2005, 46, 5043−5047. (324) Fujioka, H.; Minamitsuji, Y.; Moriya, T.; Okamoto, K.; Kubo, O.; Matsushita, T.; Murai, K. Preparation of THP-ester-derived pyridiniumtype salts and their reactions with various nucleophiles. Chem. - Asian J. 2012, 7, 1925−1933. (325) Portella, C.; Brigaud, T.; Lefebvre, O.; Plantier-Royon, R. Convergent synthesis of fluoro and gem-difluoro compounds using trifluoromethyltrimethylsilane. J. Fluorine Chem. 2000, 101, 193−198. (326) Spak, S. J.; Martin, O. R. The synthesis of an O,C-trisaccharide: the O,C-analog of methyl 4′-O-β-D-glucopyranosylgentiobioside. Tetrahedron 2000, 56, 217−224.

(290) van der Kaaden, M.; Breukink, E.; Pieters, R. J. Synthesis and antifungal properties of papulacandin derivatives. Beilstein J. Org. Chem. 2012, 8, 732−737. (291) Di Giacomo, M.; Serra, M.; Brusasca, M.; Colombo, L. Stereoselective Pd-catalyzed synthesis of quaternary α-D-C-mannosyl(S)-amino acids. J. Org. Chem. 2011, 76, 5247−5257. (292) Lehmann, U.; Awasthi, S.; Minehan, T. Palladium-catalyzed cross-coupling reactions between dihydropyranylindium reagents and aryl halides. Synthesis of C-aryl glycals. Org. Lett. 2003, 5, 2405−2408. (293) Hurd, C. D.; Bonner, W. A. The catalytic glycosylation of benzene with sugar acetates. J. Am. Chem. Soc. 1945, 67, 1759−1764. (294) Malapelle, A.; Coslovi, A.; Doisneau, G.; Beau, J.-M. An expeditious synthesis of N-acetylneuraminic acid α-C-glycosyl derivatives (“α-C-glycosides”) from the anomeric acetates. Eur. J. Org. Chem. 2007, 2007, 3145−3157. (295) Verhagen, C.; Bryld, T.; Raunkjær, M.; Vogel, S.; Buchalova, K.; Wengel, J. A conformationally locked aminomethyl C-glycoside and studies on its N-pyren-1-ylcarbonyl derivative inserted into oligodeoxynucleotides. Eur. J. Org. Chem. 2006, 2006, 2538−2548. (296) Owen, D. J.; Thomson, R. J.; von Itzstein, M. A convenient synthesis of C-galactofuranosylic compounds (C-galactofuranosides). Carbohydr. Res. 2002, 337, 2017−2022. (297) Franz, A. H.; Wei, Y.; Samoshin, V. V.; Gross, P. H. Mild synthesis of disaccharidic 2,3-enopyranosyl cyanides and 2-C-2-deoxy pyranosyl cyanides with Hg(CN)2/HgBr2/TMSCN. J. Org. Chem. 2002, 67, 7662−7669. (298) Yin, J.; Linker, T. Convenient synthesis of bicyclic carbohydrate 1,2-lactones and their stereoselective opening to 1-functionalized glucose derivatives. Chem. - Eur. J. 2009, 15, 49−52. (299) Yin, J.; Linker, T. Stereoselective diversity-oriented syntheses of functionalized saccharides from bicyclic carbohydrate 1,2-lactones. Tetrahedron 2011, 67, 2447−2461. (300) Guisot, N. E. S.; Obame, I. E.; Ireddy, P.; Nourry, A.; Saluzzo, C.; Dujardin, G.; Dubreuil, D.; Pipelier, M.; Guillarme, S. Reaction of glyconitriles with organometallic reagents: access to acyl β-C-glycosides. J. Org. Chem. 2016, 81, 2364−2371. (301) Hendrix, A. J. M.; Jennings, M. P. Convergent synthesis of (+)-aspergillide B via a highly diastereoselective oxocarbenium allylation. Tetrahedron Lett. 2010, 51, 4260−4262. (302) Ramana, C. V.; Durugkar, K. A.; Puranik, V. G.; Narute, S. B.; Prasad, B. L. V. C-Glycosides of dodecanoic acid: new capping/reducing agents for glyconanoparticle synthesis. Tetrahedron Lett. 2008, 49, 6227−6230. (303) Dondoni, A.; Giovannini, P. P.; Marra, A. A concise C-glycosyl amino acid synthesis by alkenyl C-glycoside−vinyloxazolidine crossmetathesis. Synthesis of glycosyl serine, asparagine and hydroxynorvaline isosteres. J. Chem. Soc., Perkin Trans. 1 2001, 2380−2388. (304) Kramer, J. R.; Deming, T. J. Glycopolypeptides via living polymerization of glycosylated-L-lysine N-carboxyanhydrides. J. Am. Chem. Soc. 2010, 132, 15068−15071. (305) Liu, Z.; Bittman, R. Synthesis of C-glycoside analogues of αgalactosylceramide via linear allylic C−H oxidation and allyl cyanate to isocyanate rearrangement. Org. Lett. 2012, 14, 620−623. (306) Brenna, E.; Fuganti, C.; Grasselli, P.; Serra, S.; Zambotti, S. A novel general route for the synthesis of C-glycosyl tyrosine analogues. Chem. - Eur. J. 2002, 8, 1872−1878. (307) Lu, X.; Song, L.; Metelitsa, L. S.; Bittman, R. Synthesis and evaluation of an α-C-galactosylceramide analogue that induces Th1biased responses in human natural killer T cells. ChemBioChem 2006, 7, 1750−1756. (308) Martinez-Solorio, D.; Belmore, K. A.; Jennings, M. P. Synthesis of the purported ent-pochonin J. structure featuring a stereoselective oxocarbenium allylation. J. Org. Chem. 2011, 76, 3898−3908. (309) Albury, A. M. M.; Jennings, M. P. Syntheses of (−)-cryptocaryolone and (−)-cryptocaryolone diacetate via a diastereoselective oxyMichael addition and oxocarbenium allylation. J. Org. Chem. 2012, 77, 6929−6936. 12345


Chemical Reviews

Review

(348) Brimble, M. A.; Brenstrum, T. J. Synthesis of a Cglycosylpyranonaphthoquinone related to medermycin. Tetrahedron Lett. 2000, 41, 2991−2994. (349) dos Santos, R. G.; Jesus, A. R.; Caio, J. M.; Rauter, A. P. Friestype reactions for the C-glycosylation of phenols. Curr. Org. Chem. 2011, 15, 128−148. (350) Suzuki, K. Lessons from total synthesis of hybrid natural products. Chem. Rec. 2010, 10, 291−307. (351) Suzuki, K. Synthetic study of ravidomycin, a hybrid natural product. Pure Appl. Chem. 2000, 72, 1783−1786. (352) Ben, A.; Hsu, D.-S.; Matsumoto, T.; Suzuki, K. Total synthesis and structure revision of deacetylravidomycin M. Tetrahedron 2011, 67, 6460−6468. (353) Kitamura, K.; Shigeta, M.; Maezawa, Y.; Watanabe, Y.; Hsu, D.S.; Ando, Y.; Matsumoto, T.; Suzuki, K. Preparation of L-vancosaminerelated glycosyl donors. J. Antibiot. 2013, 66, 131−139. (354) Yamauchi, T.; Watanabe, Y.; Suzuki, K.; Matsumoto, T. Facile one-pot synthesis of resorcinol bis-C-glycosides possessing two identical sugar moieties. Synthesis 2006, 2006, 2818−2824. (355) Brimble, M. A.; Brenstrum, T. J. C-Glycosylation of tri-O-benzyl2-deoxy- D -glucose: synthesis of naphthyl-substituted 3,6dioxabicyclo[3.2.2]nonanes. J. Chem. Soc., Perkin Trans. 1 2001, 1612−1623. (356) Brimble, M. A.; Brenstrum, T. J. Synthesis of a 2-deoxyglucosyl analogue of medermycin. J. Chem. Soc., Perkin Trans. 1 2001, 1624− 1634. (357) Brimble, M. A. Synthetic studies toward pyranonaphthoquinone antibiotics. Pure Appl. Chem. 2000, 72, 1635−1639. (358) Brimble, M. A.; Brenstrum, T. J. Synthesis of naphthyl Cglycosides of rearranged tri-O-benzyl-2-deoxy-D-glucose. Tetrahedron Lett. 2000, 41, 1107−1110. (359) Brimble, M. A.; Brenstrum, T. J. Synthesis of a Cglycosylpyranonaphthoquinone related to medermycin. Tetrahedron Lett. 2000, 41, 2991−2994. (360) Brenstrum, T. J.; Brimble, M. A. C-Glycosylation of naphthols using glycosyl donors. ARKIVOC 2001, 2001 (vii), 37−48. (361) Bellosta, V.; Czernecki, S. Stereocontrolled synthesis of Cglycosides by reaction of organocuprates with protected 1,2-anhydro sugars, and their transformation into 2-deoxy-C-glycosides. J. Chem. Soc., Chem. Commun. 1989, 199−200. (362) Smoliakova, I. P. Synthesis of C-glycosylic compounds using three-membered cyclic intermediates. Curr. Org. Chem. 2000, 4, 589− 608. (363) Chiara, J. L.; Sesmilo, E. Samarium diiodide-mediated reductive coupling of epoxides and carbonyl compounds: a stereocontrolled synthesis of C-glycosides from 1,2-anhydro sugars. Angew. Chem., Int. Ed. 2002, 41, 3242−3246. (364) Parrish, J. D.; Little, R. D. Preparation of α-C-glycosides from glycals. Org. Lett. 2002, 4, 1439−1442. (365) Manabe, S.; Marui, Y.; Ito, Y. Total synthesis of mannosyl tryptophan and its derivatives. Chem. - Eur. J. 2003, 9, 1435−1447. (366) Allwein, S. P.; Cox, J. M.; Howard, B. E.; Johnson, H. W. B.; Rainier, J. D. C-Glycosides to fused polycyclic ethers. Tetrahedron 2002, 58, 1997−2009. (367) Osei Akoto, C.; Rainier, J. D. Harnessing glycal-epoxide rearrangements: the generation of the AB, EF, and IJ rings of adriatoxin. Angew. Chem., Int. Ed. 2008, 47, 8055−8058. (368) Majumder, U.; Cox, J. M.; Johnson, H. W. B.; Rainier, J. D. Total synthesis of gambierol: the generation of the A−C and F−H subunits by using a C-glycoside centered strategy. Chem. - Eur. J. 2006, 12, 1736− 1746. (369) Boulineau, F. P.; Wei, A. Synthesis of L-sugars from 4deoxypentenosides. Org. Lett. 2002, 4, 2281−2283. (370) Sanhueza, C. A.; Mayato, C.; Garcia-Chicano, M.; Diaz-Penate, R.; Dorta, R. L.; Vazquez, J. T. Antiproliferation and apoptosis induced by C-glycosides in human leukemia cancer cells. Bioorg. Med. Chem. Lett. 2006, 16, 4223−4227.

(327) Li, Y.; Yin, Z.; Wang, B.; Meng, X.-B.; Li, Z.-J. Synthesis of orthogonally protected L-glucose, L-mannose, and L-galactose from Dglucose. Tetrahedron 2012, 68, 6981−6989. (328) Lin, L.; He, X.-P.; Xu, Q.; Chen, G.-R.; Xie, J. Synthesis of β-Cglycopyranosyl-1,4-naphthoquinone derivatives and their cytotoxic activity. Carbohydr. Res. 2008, 343, 773−779. (329) He, L.; Galland, S.; Dufour, C.; Chen, G.-R.; Dangles, O.; Fenet, B.; Praly, J.-P. C-D-Glucopyranosyl derivatives of tocopherols − synthesis and evaluation as amphiphilic antioxidants. Eur. J. Org. Chem. 2008, 2008, 1869−1883. (330) He, L.; Zhang, Y. Z.; Tanoh, M.; Chen, G.-R.; Praly, J.-P.; Chrysina, E. D.; Tiraidis, C.; Kosmopoulou, M.; Leonidas, D. D.; Oikonomakos, N. G. In the search of glycogen phosphorylase inhibitors: synthesis of C-D-glycopyranosylbenzo(hydro)quinones − inhibition of and binding to glycogen phosphorylase in the crystal. Eur. J. Org. Chem. 2007, 2007, 596−606. (331) Kinfe, H. K.; Moshapo, P. T.; Makolo, F. L.; Muller, A. Facile diastereoselective synthesis of carbohydrate-based thiochromans. J. Carbohydr. Chem. 2013, 32, 139−157. (332) Kinfe, H. K.; Moshapo, P. T.; Makolo, F. L.; Gammon, D. W.; Ehlers, M.; Schmuck, C. Preparation and antimalarial activity of a novel class of carbohydratederived, fused thiochromans. Eur. J. Med. Chem. 2014, 87, 197−202. (333) Probst, N.; Martin, A.; Desire, J.; Mingot, A.; Marrot, J.; Bleriot, Y.; Thibaudeau, S. HF-induced intramolecular C-arylation and Calkylation/fluorination of 2-aminoglycopyranoses. Org. Lett. 2017, 19, 1040−1043. (334) Shuto, S.; Horne, G.; Marwood, R. D.; Potter, B. V. L Total synthesis of nucleobase-modified adenophostin A mimics. Chem. - Eur. J. 2001, 7, 4937−4946. (335) Kitamura, K.; Ando, Y.; Matsumoto, T.; Suzuki, K. Synthesis of the pluramycins 1: two designed anthrones as enabling platforms for flexible bis-C-glycosylation. Angew. Chem., Int. Ed. 2014, 53, 1258−1261. (336) Fei, Z.; McDonald, F. E. Stereo- and regioselective glycosylations to the bis-C-arylglycoside of kidamycin. Org. Lett. 2007, 9, 3547−3550. (337) Wei, X.; Liang, D.; Wang, Q.; Meng, X.; Li, Z. Total synthesis of mangiferin, homomangiferin, and neomangiferin. Org. Biomol. Chem. 2016, 14, 8821−8831. (338) Cermola, F.; Iesce, M. R.; Buonerba, G. Dye-sensitized photooxygenation of furanosyl furans: synthesis of a new pyridazine C-nucleoside. J. Org. Chem. 2005, 70, 6503−6505. (339) O’Keefe, B. M.; Mans, D. M.; Kaelin, D. E., Jr; Martin, S. F. Total synthesis of isokidamycin. J. Am. Chem. Soc. 2010, 132, 15528−15530. (340) O’Keefe, B. M.; Mans, D. M.; Kaelin, D. E., Jr; Martin, S. F. Studies toward the syntheses of pluramycin natural products. The first total synthesis of isokidamycin. Tetrahedron 2011, 67, 6524−6538. (341) Shigeta, M.; Hakamata, T.; Watanabe, Y.; Kitamura, K.; Ando, Y.; Suzuki, K.; Matsumoto, T. Efficient bis-C-aminoglycosylation toward the synthesis of the pluramycins. Synlett 2010, 2010, 2654−2658. (342) Ben, A.; Yamauchi, T.; Matsumoto, T.; Suzuki, K. Sc(OTf)3 as efficient catalyst for aryl C-glycoside synthesis. Synlett 2004, 225−230. (343) Hsu, D.-S.; Matsumoto, T.; Suzuki, K. Synthesis of Lvancosamine derivatives from methyl α-D-mannopyranoside. Synlett 2006, 2006, 469−471. (344) Osman, H.; Larsen, D. S.; Simpson, J. Synthesis of orthogonally protected D-olivoside, 1,3-di-O-acetyl-4-O-benzyl-2,6-dideoxy-D-arabinopyranose, as a C-glycosyl donor. Tetrahedron 2009, 65, 4092−4098. (345) Parker, K. A.; Ding, Q.-j. Relative reactivities of aminoglycosides and their synthetic equivalents in the C-glycosylation of aromatics. Synthesis of the pseudoaglycone (D-C-glycoside) of the benzanthrins. Tetrahedron 2000, 56, 10255−10261. (346) Morton, G. E.; Barrett, A. G. M. Iterative benzyne-furan cycloaddition reactions: studies toward the total synthesis of ent-Sch 47554 and ent-Sch 47555. Org. Lett. 2006, 8, 2859−2861. (347) Chen, Q.; Zhong, Y.; O’Doherty, G. A. Convergent de novo synthesis of vineomycinone B2 methyl ester. Chem. Commun. 2013, 49, 6806−6808. 12346


Chemical Reviews

Review

(371) Mayato, C.; Dorta, R. L.; Vazquez, J. T. The exo-deoxoanomeric effect in the conformational preferences of C-glycosides. Tetrahedron: Asymmetry 2007, 18, 931−948. (372) Doddi, V. R.; Kancharla, P. K.; Reddy, Y. S.; Kumar, A.; Vankar, Y. D. Synthesis of fused pyran-carbahexopyranoses as glycosidase inhibitors. Carbohydr. Res. 2009, 344, 606−612. (373) Cox, J. M.; Rainier, J. D. C-Glycosides to fused polycyclic ethers. An efficient entry into the A-D ring system of gambierol. Org. Lett. 2001, 3, 2919−2922. (374) Majumder, U.; Cox, J. M.; Rainier, J. D. Synthesis of an F-H gambierol subunit using a C-glycoside-centered strategy. Org. Lett. 2003, 5, 913−916. (375) Roberts, S. W.; Rainier, J. D. Substitution and remote protecting group influence on the oxidation/addition of α-substituted 1,2anhydroglycosides: a novel entry into C-ketosides. Org. Lett. 2005, 7, 1141−1144. (376) Chang, R.; Vo, T. T.; Finney, N. S. Synthesis of the C1phosphonate analog of UDP-GlcNAc. Carbohydr. Res. 2006, 341, 1998− 2004. (377) Rainier, J. D.; Cox, J. M. Aluminum- and boron-mediated Cglycoside synthesis from 1,2-anhydroglycosides. Org. Lett. 2000, 2, 2707−2709. (378) Xue, S.; Han, K.-Z.; He, L.; Guo, Q.-X. Zinc-mediated synthesis of α-C-glycosides from 1,2-anhydroglycosides. Synlett 2003, 870−872. (379) Wagschal, S.; Guilbaud, J.; Rabet, P.; Farina, V.; Lemaire, S. α-CGlycosides via syn opening of 1,2-anhydro sugars with organozinc compounds in toluene/n-dibutyl ether. J. Org. Chem. 2015, 80, 9328− 9335. (380) Cheng, G.; Fan, R.; Hernandez-Torres, J. M.; Boulineau, F. P.; Wei, A. syn Additions to 4α-epoxypyranosides: synthesis of Lidopyranosides. Org. Lett. 2007, 9, 4849−4852. (381) Leeuwenburgh, M. A.; van der Marel, G. A.; Overkleeft, H. S.; van Boom, J. H. From α-1,2-anhydrosugars to C-glycosides: the influence of Lewis acids and nucleophiles on the stereochemistry. J. Carbohydr. Chem. 2003, 22, 549−564. (382) Tatina, M. B.; Kusunuru, A. K.; Mukherjee, D. Organo-zinc promoted diastereoselective C-arylation of 1,2-anhydrosugars from arylboronic acids. Org. Lett. 2015, 17, 4624−4627. (383) Wipf, P.; Pierce, J. G.; Zhuang, N. Silver(I)-catalyzed addition of zirconocenes to glycal epoxides. A new synthesis of α-C-glycosides. Org. Lett. 2005, 7, 483−485. (384) Nishiguchi, G. A.; Little, R. D. From C-glycosides to pyranopyrans: an approach to thyrsiferol using titanium(III)-promoted redox couplings. J. Org. Chem. 2005, 70, 5249−5256. (385) Lian, G.; Zhang, X.; Yu, B. Thioglycosides in Carbohydrate Research. Carbohydr. Res. 2015, 403, 13−22. (386) Williams, R. W.; Stewart, A. O. C-Glycosidation of pyridyl thioglycosides. Tetrahedron Lett. 1983, 24, 2715−2718. (387) Keck, G. E.; Enholm, E. J.; Kachensky, D. F. Two new methods for the synthesis of C-glycosides. Tetrahedron Lett. 1984, 25, 1867− 1870. (388) Jaramillo, C.; Corrales, G.; Fernandez-Mayoralas, A. Glycosyl phenyl sulfoxides as a source of glycosyl carbanions: stereoselective synthesis of C-fucosides. Tetrahedron Lett. 1998, 39, 7783−7786. (389) Beau, J.-M.; Sinay, P. Preparation and reductive lithiation of 2deoxy-D-glucopyranosyl phenylsulfones: a highly sterteoselective route to C-glycosides. Tetrahedron Lett. 1985, 26, 6185−6188. (390) Vlahov, I. R.; Vlahova, P. I.; Linhardt, R. J. Diastereocontrolled synthesis of carbon glycosides of N-acetylneuraminic acid via glycosyl samarium(III) intermediates. J. Am. Chem. Soc. 1997, 119, 1480−1481. (391) Skrydstrup, T.; Jarreton, O.; Mazeas, D.; Urban, D.; Beau, J.-M. A general approach to 1,2-trans-C-glycosides via glycosyl samarium(III) compounds. Chem. - Eur. J. 1998, 4, 655−671. (392) Crich, D.; Sharma, I. Is donor−acceptor hydrogen bonding necessary for 4,6-O-benzylidene-directed β-mannopyranosylation? Stereoselective synthesis of β-C-mannopyranosides and α-C-glucopyranosides. Org. Lett. 2008, 10, 4731−4734. (393) Moume-Pymbock, M.; Crich, D. Stereoselective C-glycoside formation with 2-O-benzyl-4,6-O-benzylidene protected 3-deoxy gluco-

and mannopyranoside donors: comparison with O-glycoside formation. J. Org. Chem. 2012, 77, 8905−8912. (394) Crich, D.; Sharma, I. Influence of the O3 protecting group on stereoselectivity in the preparation of C-mannopyranosides with 4,6-Obenzylidene protected donors. J. Org. Chem. 2010, 75, 8383−8391. (395) Hou, D.; Lowary, T. L. 2,3-Anhydrosugars in glycoside bond synthesis: application to furanosyl azides and C-glycosides. Tetrahedron 2009, 65, 5916−5921. (396) Xiong, D.-C.; Gao, C.; Li, W.; Wang, Y.; Li, Q.; Ye, X.-S. Synthesis of 2-deoxy-C-glycosides via Lewis acid-mediated rearrangement of 2,3-anhydro-1-thiopyranosides. Org. Chem. Front. 2014, 1, 798−806. (397) Kulkarni, S. S.; Liu, Y.-H.; Hung, S.-C. Neighboring group participation of 9-anthracenylmethyl group in glycosylation: preparation of unusual C-glycosides. J. Org. Chem. 2005, 70, 2808−2811. (398) Gu, Z.-y.; Zhang, X.-t.; Zhang, J.-x.; Xing, G.-w. Highly efficient α-C-sialylation promoted by (p-Tol)2SO/Tf2O with N-acetyl-5-N,4-Ooxazolidione protected thiosialoside as donor. Org. Biomol. Chem. 2013, 11, 5017−5022. (399) McGarvey, G. J.; LeClair, C. A.; Schmidtmann, B. A. Studies on the stereoselective synthesis of C-allyl glycosides. Org. Lett. 2008, 10, 4727−4730. (400) Brown, D. S.; Ley, S. V. Direct substitution of 2benzenesulphonyl cyclic ethers using organozinc reagents. Tetrahedron Lett. 1988, 29, 4869−4872. (401) Angle, S. R.; Shaw, S. Z. Stereoselective synthesis of 3-hydroxy-2sulfonyltetrahydrofurans from β-(triethylsilyloxy)aldehydes and ptolylsulfonyldiazomethane. Tetrahedron 2001, 57, 5227−5232. (402) Abdallah, Z.; Doisneau, G.; Beau, J.-M. Synthesis of a carbonlinked mimic of the disaccharide component of the tumor-related sialylTn antigen. Angew. Chem., Int. Ed. 2003, 42, 5209−5212. (403) Carpintero, M.; Nieto, I.; Fernandez-Mayoralas, A. Stereospecific synthesis of α- and β-C-glycosides from glycosyl sulfoxides: scope and limitations. J. Org. Chem. 2001, 66, 1768−1774. (404) Carpintero, M.; Jaramillo, C.; Fernandez-Mayoralas, A. Stereoselective synthesis of carba- and C-glycosyl analogs of fucopyranosides. Eur. J. Org. Chem. 2000, 2000, 1285−1296. (405) Li, G.; Xiong, D.-C.; Ye, X.-S. Synthesis of α-C-glycosides by samarium diiodide mediated coupling of glycosyl pyridyl sulfones with alkenes. Synlett 2011, 2011, 2410−2414. (406) De Vicente, J.; Betzemeier, B.; Rychnovsky, S. D. A Cglycosidation approach to the central core of amphidinol 3: synthesis of the C39−C52 fragment. Org. Lett. 2005, 7, 1853−1856. (407) Soengas, R. G.; Estevez, A. M. Applications of Barbier type reactions in carbohydrate chemistry. Curr. Org. Synth. 2013, 10, 183− 209. (408) Wang, J.; Gasc, F.; Prandi, J. Samarium diiodide mediated coupling of 2-pyridylsulfonyl furanosides with aldehydes and ketones: a general synthesis of C-furanosides. Eur. J. Org. Chem. 2015, 2015, 2691− 2697. (409) Mikkelsen, L. M.; Skrydstrup, T. Synthesis of the C-linked disaccharide α-D-Man-(1→4)-D-Man employing a SmI2-mediated Cglycosylation step: en route to cyclic C-oligosaccharides. J. Org. Chem. 2003, 68, 2123−2128. (410) Leon, E. I.; Martin, A.; Perez-Martin, I.; Quintanal, L. M.; Suarez, E. Hydrogen atom transfer experiments provide chemical evidence for the conformational differences between C- and O-disaccharides. Eur. J. Org. Chem. 2010, 2010, 5248−5262. (411) Mikkelsen, L. M.; Krintel, S. L.; Jimenez-Barbero, J.; Skrydstrup, T. Application of the anomeric samarium route for the convergent synthesis of the C-linked trisaccharide α-D-Man-(1→3)-[α-D-Man-(1→ 6)]-D-Man and the disaccharides α-D-Man-(1→3)-D-Man and α-D-Man(1→6)-D-Man. J. Org. Chem. 2002, 67, 6297−6308. (412) Ren, Z.-X.; Yang, Q.; Price, K. N.; Chen, T.; Nygren, C.; Turner, J. F. C.; Baker, D. C. Synthesis of a C-linked hyaluronic acid disaccharide mimetic. Carbohydr. Res. 2007, 342, 1668−1679. (413) Palmier, S.; Vauzeilles, B.; Beau, J.-M. A highly selective route to β-C-glycosides via nonselective samarium iodide induced coupling reactions. Org. Biomol. Chem. 2003, 1, 1097−1098. 12347


Chemical Reviews

Review

(414) Miquel, N.; Doisneau, G.; Beau, J.-M. Reductive samariation of anomeric 2-pyridyl sulfones with catalytic nickel: an unexpected improvement in the synthesis of 1,2-trans-diequatorial C-glycosyl compounds. Angew. Chem., Int. Ed. 2000, 39, 4111−4114. (415) Wang, Q.; Linhardt, R. J. Synthesis of a serine-based neuraminic acid C-glycoside. J. Org. Chem. 2003, 68, 2668−2672. (416) Wang, Q.; Dordick, J. S.; Linhardt, R. J. Chemoenzymatic synthesis of neuraminic acid containing C-glycoside polymers. Org. Lett. 2003, 5, 1187−1189. (417) Zhang, C.; Ma, X.; Du, Y. Synthesis of Neu5Ac-α-Cgalactopyranosyl-functionalized magnetic nanoparticles via click chemistry. Tetrahedron 2013, 69, 7300−7307. (418) Kuberan, B.; Sikkander, S. A.; Tomiyama, H.; Linhardt, R. J. Synthesis of a C-glycoside analogue of sTn: an HIV- and tumorassociated antigen. Angew. Chem., Int. Ed. 2003, 42, 2073−2075. (419) Yuan, X.; Ress, D. K.; Linhardt, R. J. Synthesis of nor-C-linked neuraminic acid disaccharide: a versatile precursor of C-analogs of oligosialic acids and gangliosides. J. Org. Chem. 2007, 72, 3085−3088. (420) Ress, D. K.; Baytas, S. N.; Wang, Q.; Munoz, E. M.; Tokuzoki, K.; Tomiyama, H.; Linhardt, R. J. Synthesis of double C-glycoside analogue of sTn. J. Org. Chem. 2005, 70, 8197−8200. (421) Kim, J.-H.; Huang, F.; Ly, M.; Linhardt, R. J. Stereoselective synthesis of a C-linked neuraminic acid disaccharide: potential building block for the synthesis of C-analogues of polysialic acids. J. Org. Chem. 2008, 73, 9497−9500. (422) Wang, Q.; Wolff, M.; Polat, T.; Du, Y.; Linhardt, R. J. Inhibition of neuraminidase with neuraminic acid C-glycosides. Bioorg. Med. Chem. Lett. 2000, 10, 941−944. (423) Adlington, R. W.; Baldwin, J. E.; Basak, A.; Kozyrod, R. P. Applications of radical addition reactions to the synthesis of a Cglucoside and a functionalised amino-acid. J. Chem. Soc., Chem. Commun. 1983, 944−945. (424) Barton, D. H. R.; Ramesh, M. Tandem nucleophilic and radical chemistry in the replacement of the hydroxyl group by a carbon−carbon bond. A concise synthesis of showdomycin. J. Am. Chem. Soc. 1990, 112, 891−892. (425) He, W.; Togo, H.; Yokoyama, M. Strategic approach to Cnucleosides via sugar anomeric radical, cation, and anion with sugar tellurides. Tetrahedron Lett. 1997, 38, 5541−5544. (426) Terauchi, M.; Abe, H.; Tovey, S. C.; Dedos, S. G.; Taylor, C. W.; Paul, M.; Trusselle, M.; Potter, B. V. L; Matsuda, A.; Shuto, S. A systematic study of C-glucoside trisphosphates as myo-inositol trisphosphate receptor ligands. Synthesis of β-C-glucoside trisphosphates based on the conformational restriction strategy. J. Med. Chem. 2006, 49 (49), 1900−1909. (427) Shuto, S.; Yahiro, Y.; Ichikawa, S.; Matsuda, A. Synthesis of 3,7anhydro-D-glycero-D-ido-octitol 1,5,6-trisphosphate as an IP3 receptor ligand using a radical cyclization reaction with a vinylsilyl tether as the key step. Conformational restriction strategy using steric repulsion between adjacent bulky protecting groups on a pyranose ring. J. Org. Chem. 2000, 65, 5547−5557. (428) Abe, H.; Shuto, S.; Matsuda, A. Synthesis of the C-glycosidic analogue of adenophostin A and its uracil congener as potential IP3 receptor ligands. Stereoselective construction of the C-glycosidic structure by a temporary silicon-tethered radical coupling reaction. J. Org. Chem. 2000, 65, 4315−4325. (429) Terauchi, M.; Yahiro, Y.; Abe, H.; Ichikawa, S.; Tovey, S. C.; Dedos, S. G.; Taylor, C. W.; Potter, B. V. L; Matsuda, A.; Shuto, S. Synthesis of 4,8-anhydro-D-glycero-D-ido-nonanitol 1,6,7-trisphosphate as a novel IP3 receptor ligand using a stereoselective radical cyclization reaction based on a conformational restriction strategy. Tetrahedron 2005, 61, 3697−3707. (430) Shuto, S.; Terauchi, M.; Yahiro, Y.; Abe, H.; Ichikawa, S.; Matsuda, A. Stereoselective synthesis of α- and β-C-glucosides via radical cyclization with an allylsilyl tether. Control of the stereoselectivity by changing the conformation of the pyranose ring. Tetrahedron Lett. 2000, 41, 4151−4155. (431) Abe, H.; Shuto, S.; Matsuda, A. Highly α- andβ-selective radical C-glycosylation reactions using a controlling anomeric effect based on

the conformational restriction strategy. A study on the conformationanomeric effect-stereoselectivity relationship in anomeric radical reactions. J. Am. Chem. Soc. 2001, 123, 11870−11882. (432) Abe, H.; Terauchi, M.; Matsuda, A.; Shuto, S. A study on the conformation-anomeric effect-stereoselectivity relationship in anomeric radical reactions, using conformationally restricted glucose derivatives as substrates. J. Org. Chem. 2003, 68, 7439−7447. (433) Terauchi, M.; Matsuda, A.; Shuto, S. Efficient synthesis of β-Cglucosides via radical cyclization with a silicon tether based on the conformational restriction strategy. Tetrahedron Lett. 2005, 46, 6555− 6558. (434) Brusa, C.; Muzard, M.; Remond, C.; Plantier-Royon, R. βXylopyranosides: synthesis and applications. RSC Adv. 2015, 5, 91026− 91055. (435) Kim, G.; Kim, H. S. C-Glycosylation via radical cyclization: synthetic application to a new C-glycoside. Tetrahedron Lett. 2000, 41, 225−227. (436) Grant, L.; Liu, Y.; Walsh, K. E.; Walter, D. S.; Gallagher, T. Galacto, gluco, manno, and disaccharide-based C-glycosides of 2-amino2-deoxy sugars. Org. Lett. 2002, 4, 4623−4625. (437) SanMartin, R.; Tavassoli, B.; Walsh, K. E.; Walter, D. S.; Gallagher, T. Radical-mediated synthesis of α-C-glycosides based on Nacyl galactosamine. Org. Lett. 2000, 2, 4051−4054. (438) Liu, Y.; Gallagher, T. C-Glycosides of 2-amino-2-deoxy sugars. βC-glycosides and 1,1-disubstituted variants. Org. Lett. 2004, 6, 2445− 2448. (439) Yamago, S.; Hashidume, M.; Yoshida, J.-i. A new synthetic route to substituted quinones by radical-mediated coupling of organotellurium compounds with quinones. Tetrahedron 2002, 58, 6805− 6813. (440) Micheel, F.; Stanek, J., jr. Bildung carbocyclischer verbindungen aus D-glucose und anisol in wasserfreiem fluorwasserstoff. Tetrahedron Lett. 1970, 11, 1609−1612. (441) Acton, E. M.; Ryan, K. J.; Smith, T. H. C-Daunosaminyl derivatives by the Wittig reaction. Carbohydr. Res. 1981, 97, 235−245. (442) Rodrigues, F.; Canac, Y.; Lubineau, A. A convenient, one-step, synthesis of β-C-glycosidic ketones in aqueous media. Chem. Commun. 2000, 2049−2050. (443) Villadsen, K.; Martos-Maldonado, M. C.; Jensen, K. J.; Thygesen, M. B. Chemoselective reactions for the synthesis of glycoconjugates from unprotected carbohydrates. ChemBioChem 2017, 18, 574−612. (444) Hanessian, S.; Lou, B. Stereocontrolled glycosyl transfer reactions with unprotected glycosyl donors. Chem. Rev. 2000, 100, 4443−4463. (445) Toshima, K. Novel glycosylation methods and their application to natural products synthesis. Carbohydr. Res. 2006, 341, 1282−1297. (446) Pasetto, P.; Walczak, M. C. A Mitsunobu route to C-glycosides. Tetrahedron 2009, 65, 8468−8477. (447) Subramanian, P.; Kaliappan, K. P. A one-pot, copper-catalyzed cascade route to 2-indolyl-C-glycosides. Eur. J. Org. Chem. 2013, 2013, 595−604. (448) Senthil Kumar, R.; Karthikeyan, K.; Phani Kumar, B. V. N.; Muralidharan, D.; Perumal, P. T. Synthesis of densely functionalised Cglycosides by a tandem oxy Michael addition−Wittig olefination pathway. Carbohydr. Res. 2010, 345, 457−461. (449) McAllister, G. D.; Paterson, D. E.; Taylor, R. J. K. A simplified Ramberg−Bäcklund approach to novel C-glycosides and C-linked disaccharides. Angew. Chem., Int. Ed. 2003, 42, 1387−1391. (450) Dominguez, Z. J.; Marchand, P.; Gulea, M.; Masson, S. Synthesis of new 2-C-(2,3:5,6-di-O-isopropylidene)-β-D-mannofuranosyldithioacetate derivatives. Carbohydr. Res. 2005, 340, 579−586. (451) Francisco, C. G.; Herrera, A. J.; Suarez, E. Intramolecular hydrogen abstraction Reaction promoted by alkoxy radicals in carbohydrates. Synthesis of chiral 2,7-dioxabicyclo[2.2.1]heptane and 6,8-dioxabicyclo[3.2.1]octane ring systems. J. Org. Chem. 2002, 67, 7439−7445. 12348


Chemical Reviews

Review

(452) Jeanmart, S.; Taylor, R. J. K. A protecting group-free approach to C-glycosides using the Ramberg−Bäcklund reaction. Tetrahedron Lett. 2005, 46, 9043−9048. (453) Borodkin, V. S.; Ferguson, M. A. J.; Nikolaev, A. V. Synthesis of β-D-Galp-(1→4)-α-D-Manp methanephosphonate, a substrate analogue for the elongating α-D-mannosyl phosphate transferase in the Leishmania. Tetrahedron Lett. 2001, 42, 5305−5308. (454) Sridhar, P. R.; Seshadri, K.; Reddy, G. M. Stereoselective synthesis of sugar fused β-disubstituted γ-butyro-lactones: C-spiroglycosides from 1,2-cyclopropanecarboxylated sugars. Chem. Commun. 2012, 48, 756−758. (455) Shirakawa, S.; Kobayashi, S. Surfactant-type Brønsted acid catalyzed dehydrative nucleophilic substitutions of alcohols in water. Org. Lett. 2007, 9, 311−314. (456) Saito, T.; Nishimoto, Y.; Yasuda, M.; Baba, A. Direct coupling reaction between alcohols and silyl compounds: enhancement of Lewis acidity of Me3SiBr using InCl3. J. Org. Chem. 2006, 71, 8516−8522. (457) Schmitt, A.; Reißig, H.-U. On the stereoselectivity of γ-lactol substitutions with allyl- and propargylsilanes − synthesis of disubstituted tetrahydrofuran derivatives. Eur. J. Org. Chem. 2000, 2000, 3893−3901. (458) Schmitt, A.; Reißig, H.-U. Lewis acid-promoted reactions of γlactols with silyl enol ethers − stereoselective formation of functionalized tetrahydrofuran derivatives. Eur. J. Org. Chem. 2001, 2001, 1169− 1174. (459) Padhi, B.; Reddy, D. S.; Mohapatra, D. K. Gold-catalyzed diastereoselective synthesis of 2,6-trans-disubstituted tetrahydropyran derivatives: application for the synthesis of the C1−C13 fragment of bistramide A and B. RSC Adv. 2015, 5, 96758−96768. (460) Nolting, B.; Yu, J.-J.; Liu, G.-y.; Cho, S.-J.; Kauzlarich, S.; GervayHague, J. Synthesis of gold glyconanoparticles and biological evaluation of recombinant Gp120 interactions. Langmuir 2003, 19, 6465−6473. (461) Baker, K. W. J.; March, A. R.; Parsons, S.; Paton, R. M.; Stewart, G. W. 3,4-Dipyranosyl-1,2,5-oxadiazole 2-oxides: synthesis and X-ray structure. Tetrahedron 2002, 58, 8505−8513. (462) Franz, A. H.; Gross, P. H.; Samoshin, V. V. Syntheses of small cluster oligosaccharide mimetics. ARKIVOC 2008, 2008 (i), 271−308. (463) Baker, K. W. J.; Gibb, A.; March, A. R.; Parsons, S.; Paton, R. M. A convenient synthesis of pyranosyl-1-carbaldoximes. Synth. Commun. 2003, 33, 1707−1715. (464) Phiasivongsa, P.; Samoshin, V. V.; Gross, P. H. Henry condensations with 4,6-O-benzylidenylated and non-protected Dglucose and L-fucose via DBU-catalysis. Tetrahedron Lett. 2003, 44, 5495−5498. (465) Baker, K. W. J.; Horner, K. S.; Moggach, S. A.; Paton, R. M.; Smellie, I. A. S. Synthesis of pyranosyl amidoximes by addition of amines to pyranosyl nitrile oxides. Tetrahedron Lett. 2004, 45, 8913−8916. (466) Caraballo, R.; Sakulsombat, M.; Ramström, O. Towards dynamic drug design: identification and optimization of β-galactosidase inhibitors from a dynamic hemithioacetal system. ChemBioChem 2010, 11, 1600−1606. (467) Queneau, Y.; Pinel, C.; Scherrmann, M.-C. Some chemical transformations of carbohydrates in aqueous medium. C. R. Chim. 2011, 14, 688−699. (468) Bragnier, N.; Scherrmann, M.-C. One-step synthesis of β-Cglycosidic ketones in aqueous media: the case of 2-acetamido sugars. Synthesis 2005, 2005, 814−818. (469) Graziani, A.; Amer, H.; Zamyatina, A.; Hofinger, A.; Kosma, P. Synthesis of C-glycosides related to glycero-β-D-manno-heptoses. Tetrahedron: Asymmetry 2005, 16, 167−175. (470) Palasz, A.; Kalinowska-Tluscik, J.; Jablonski, M. Application of 2,4,6-trioxo-pyrimidin-5-ylidene alditols in the synthesis of pyrano[2,3d]pyrimidines containing a sugar moiety by hetero-Diels−Alder reactions and by conjugate Michael addition−cyclizations. Tetrahedron 2013, 69, 8216−8227. (471) Critchley, P.; Clarkson, G. J. Carbohydrate−protein interactions at interfaces: comparison of the binding of Ricinus communis lectin to two series of synthetic glycolipids using surface plasmon resonance studies. Org. Biomol. Chem. 2003, 1, 4148−4159.

(472) Riafrecha, L. E.; Rodriguez, O. M.; Vullo, D.; Supuran, C. T.; Colinas, P. A. Synthesis of C-cinnamoyl glycosides and their inhibitory activity against mammalian carbonic anhydrases. Bioorg. Med. Chem. 2013, 21, 1489−1494. (473) Fenger, T. H.; Brumer, H. Synthesis and analysis of specific covalent inhibitors of endo-xyloglucanases. ChemBioChem 2015, 16, 575−583. (474) Feng, W.; Fang, Z.; Yang, J.; Zheng, B.; Jiang, Y. Microwaveassisted efficient synthesis of aryl ketone β-C-glycosides from unprotected aldoses. Carbohydr. Res. 2011, 346, 352−356. (475) Carpenter, C. A.; Kenar, J. A.; Price, N. P. J. Preparation of saturated and unsaturated fatty acid hydrazides and long chain Cglycoside ketohydrazones. Green Chem. 2010, 12, 2012−2018. (476) Yadav, L. D. S.; Rai, V. K. An expeditious synthesis of benzoxazine-2-thione C-nucleosides via Cu(OTf)2-mediated dehydrazinative β-glycosylation. Nucleosides, Nucleotides Nucleic Acids 2008, 27, 1227−1237. (477) Ajay, A.; Sharma, S.; Gupt, M. P.; Bajpai, V.; Hamidullah; Kumar, B.; Kaushik, M. P.; Konwar, R.; Ampapathi, R. S.; Tripathi, R. P. Diversity oriented synthesis of pyran based polyfunctional stereogenic macrocyles and their conformational studies. Org. Lett. 2012, 14, 4306− 4309. (478) Yadav, J. S.; Reddy, B. V. S.; Sreenivas, M.; Satheesh, G. Indium(III) chloride/water: a versatile catalytic system for the synthesis of C-furyl glycosides and trihydroxyalkyl furan derivatives. Synthesis 2007, 2007, 1712−1716. (479) Li, B.; Wang, G.; Li, Z.; Meng, X. InCl3-catalyzed synthesis of Cpyrrolyl glycosides via tandem condensation of aminosugars and 1,3dicarbonyl compounds in water. Tetrahedron Lett. 2011, 52, 3891− 3894. (480) Zhang, T.; Wang, T.; Fang, Z. Synthesis, screening and sensing applications of a novel fluorescent probe based on C-glycosides. RSC Adv. 2016, 6, 18357−18363. (481) Yadav, L. D. S.; Rai, V. K. One-pot dehydrazinative βglycosylation in aqueous media: synthesis of benzoxazinone Cnucleosides. Synlett 2007, 2007, 1227−1230. (482) Zeitouni, J.; Norsikian, S.; Lubineau, A. A convenient new route to protected and free 2,6-anhydro-D-glycero-D-gulo-heptoses (1-formylβ-D-glucopyranosides). Tetrahedron Lett. 2004, 45, 7761−7763. (483) Riemann, I.; Fessner, W.-D.; Papadopoulos, M. A.; Knorst, M. CGlycosides by aqueous condensation of β-dicarbonyl compounds with unprotected sugars. Aust. J. Chem. 2002, 55, 147−154. (484) Sato, S.; Nojiri, T.; Onodera, J.-i. Studies on the synthesis of safflomin-A, a yellow pigment in safflower petals: oxidation of 3-C-β-Dglucopyranosyl-5-methylphloroacetophenone. Carbohydr. Res. 2005, 340, 389−393. (485) Hamagami, H.; Kumazoe, M.; Yamaguchi, Y.; Fuse, S.; Tachibana, H.; Tanaka, H. 6-Azido-6-deoxy-L-idose as a heterobifunctional spacer for the synthesis of azido-containing chemical probes. Chem. - Eur. J. 2016, 22, 12884−12890. (486) Rawat, P.; Kumar, M.; Rahuja, N.; Srivastava, D. S. L.; Srivastava, A. K.; Maurya, R. Synthesis and antihyperglycemic activity of phenolic C-glycosides. Bioorg. Med. Chem. Lett. 2011, 21, 228−233. (487) Sato, S.; Akiya, T.; Suzuki, T.; Onodera, J.-i. Environmentally friendly C-glycosylation of phloroacetophenone with unprotected Dglucose using scandium(III) trifluoromethanesulfonate in aqueous media: key compounds for the syntheses of mono- and di-Cglucosylflavonoids. Carbohydr. Res. 2004, 339, 2611−2614. (488) Santos, R. G.; Xavier, N. M.; Bordado, J. C.; Rauter, A. P. Efficient and first regio- and stereoselective direct C-glycosylation of a flavanone catalysed by Pr(OTf)3 under conventional heating or ultrasound irradiation. Eur. J. Org. Chem. 2013, 2013, 1441−1447. (489) Collet, S. C.; Remi, J.-F.; Cariou, C.; Laib, S.; Guingant, A. Y.; Quang Vu, N.; Dujardin, G. A hetero Diels−Alder approach to the synthesis of the first angucyclinone and angucycline 5-aza-analogues. Tetrahedron Lett. 2004, 45, 4911−4915. (490) Ranoux, A.; Lemiegre, L.; Benoit, M.; Guegan, J.-P.; Benvegnu, T. Horner−Wadsworth−Emmons reaction of unprotected sugars in 12349


Chemical Reviews

Review

water or in the absence of any solvent: one-step access to C-glycoside amphiphiles. Eur. J. Org. Chem. 2010, 2010, 1314−1323. (491) Ranoux, A.; Lemiegre, L.; Benvegnu, T. Synthesis and evaluation of C-glycosides as hydrotropes and solubilizing agents. Sci. China: Chem. 2010, 53, 1957−1962. (492) Voigt, M.; Scheffler, U.; Mahrwald, R. Stereoselective aminecatalyzed carbohydrate chain elongation. Chem. Commun. 2012, 48, 5304−5306. (493) Voigt, M.; Mahrwald, R. Organocatalyzed cascade reactions of carbohydrates − a direct access to C-glycosides. Chem. Commun. 2014, 50, 817−819. (494) Witte, S. N. R.; Voigt, M.; Mahrwald, R. Amine-catalyzed cascade reactions of unprotected and unactivated carbohydrates: direct access to C-glycosides. Synthesis 2015, 47, 2249−2255. (495) Mahrwald, R. The long underestimated carbonyl function of carbohydrates − an organocatalyzed shot into carbohydrate chemistry. Chem. Commun. 2015, 51, 13868−13877. (496) Richter, C.; Krumrey, M.; Klaue, K.; Mahrwald, R. Cascade reactions of unprotected ketoses with ketones − a stereoselective access to C-glycosides. Eur. J. Org. Chem. 2016, 2016, 5309−5320. (497) Johnson, S.; Tanaka, F. Direct synthesis of C-glycosides from unprotected 2-N-acyl-aldohexoses via aldol condensation−oxa-Michael reactions with unactivated ketones. Org. Biomol. Chem. 2016, 14, 259− 264. (498) Wei, X.; Shi, S.; Xie, X.; Shimizu, Y.; Kanai, M. Copper(I)catalyzed dehydrative C-glycosidation of unprotected pyranoses with ketones. ACS Catal. 2016, 6, 6718−6722. (499) Wrodnigg, T. M.; Kartusch, C.; Illaszewicz, C. The Amadori rearrangement as key reaction for the synthesis of neoglycoconjugates. Carbohydr. Res. 2008, 343, 2057−2066. (500) Gallas, K.; Pototschnig, G.; Adanitsch, F.; Stütz, A. E.; Wrodnigg, T. M. The Amadori rearrangement as glycoconjugation method: synthesis of non-natural C-glycosyl type glycoconjugates. Beilstein J. Org. Chem. 2012, 8, 1619−1629. (501) Gloe, T.-E.; Stamer, I.; Hojnik, C.; Wrodnigg, T. M.; Lindhorst, T. K. Are D-manno-configured Amadori products ligands of the bacterial lectin FimH? Beilstein J. Org. Chem. 2015, 11, 1096−1104. (502) Bridiau, N.; Cabanel, S.; Maugard, T. Facile synthesis of pseudoC-glycosyl p-amino-DL-phenylalanine building blocks via Amadori rearrangement. Tetrahedron 2009, 65, 531−535. (503) Pall, C.; Hörnsten, F. Synthetische versuche mit d-glykonsaure. Ber. Dtsch. Chem. Ges. 1906, 39, 1361−1364. (504) Lewis, M. D.; Cha, J. K.; Kishi, Y. Highly stereoselective approaches to α- and β- C-glycopyranosides. J. Am. Chem. Soc. 1982, 104, 4976−4978. (505) Deshpande, P. P.; Ellsworth, B. A.; Buono, F. G.; Pullockaran, A.; Singh, J.; Kissick, T. P.; Huang, M.-H.; Lobinger, H.; Denzel, T.; Mueller, R. H. Remarkable β-selectivity in the synthesis of β-1-Carylglucosides: stereoselective reduction of acetyl-protected methyl 1-Carylglucosides without acetoxy-group participation. J. Org. Chem. 2007, 72, 9746−9749. (506) Terauchi, M.; Abe, H.; Matsuda, A.; Shuto, S. An efficient synthesis of β-C-glycosides based on the conformational restriction strategy: Lewis acid promoted silane reduction of the anomeric position with complete stereoselectivity. Org. Lett. 2004, 6, 3751−3754. (507) van Rijssel, E. R.; van Delft, P.; van Marle, D. V.; Bijvoets, M.; Lodder, G.; Overkleeft, H. S.; van der Marel, G. A.; Filippov, D. V.; Codee, J. D. C. Stereoselectivity in the Lewis acid mediated reduction of ketofuranoses. J. Org. Chem. 2015, 80, 4553−4565. (508) MacDougall, J. M.; Zhang, X.-D.; Polgar, W. E.; Khroyan, T. V.; Toll, L.; Cashman, J. R. Synthesis and in vitro biological evaluation of a carbon glycoside analogue of morphine-6-glucuronide. Bioorg. Med. Chem. Lett. 2005, 15, 1583−1586. (509) Ohba, K.; Koga, Y.; Nomura, S.; Nakata, M. Functionalized arylβ-C-glycoside synthesis by Barbier-type reaction using 2,4,6-triisopropylphenyllithium. Tetrahedron Lett. 2015, 56, 1007−1010. (510) Krohn, K.; Dörner, H.; Zukowski, M. Chemical synthesis of benzamide riboside. Curr. Med. Chem. 2002, 9, 727−731.

(511) Löppenberg, M.; Müller, H.; Pulina, C.; Oddo, A.; Teese, M.; Jose, J.; Holl, P. Synthesis and biological evaluation of flexible and conformationally constrained LpxC inhibitors. Org. Biomol. Chem. 2013, 11, 6056−6070. (512) Ohba, K.; Nakata, M. Total synthesis of Paecilomycin B. Org. Lett. 2015, 17, 2890−2893. (513) Schweizer, F.; Inazu, T. Chain extension of sugar δ-lactones with the enolate of tert-butyl bromoacetate and elaboration into functionalized C-ketosides, C-glycosides, and C-glucosyl glycines. Org. Lett. 2001, 3, 4115−4118. (514) McCartney, J. L.; Meta, C. T.; Cicchillo, R. M.; Bernardina, M. D.; Wagner, T. R.; Norris, P. Addition of lithiated C-nucleophiles to 2,3O-isopropylidene-D-erythronolactone: stereoselective formation of a furanose C-disaccharide. J. Org. Chem. 2003, 68, 10152−10155. (515) Ho, T. C.; Kamimura, H.; Ohmori, K.; Suzuki, K. Total synthesis of (+)-vicenin-2. Org. Lett. 2016, 18, 4488−4490. (516) Xu, G.; Xu, B.; Song, Y.; Sun, X. An efficient method for synthesis of bexagliflozin and its carbon-13 labeled analogue. Tetrahedron Lett. 2016, 57, 4684−4687. (517) Liu, T.; Hou, J.; Xie, W.; Li, Y.; Ren, H.; Liang, J.; Xiong, B.; Chen, G.; Cheng, M.; Zhao, D.; Shen, J.; Chen, Y.-L. Stereoselective and regioselective preparation of C-pentapyranosides and formal synthesis of omarigliptin. Eur. J. Org. Chem. 2016, 2016, 5624−5628. (518) Müller, H.; Gabrielli, V.; Agoglitta, O.; Holl, R. Chiral pool synthesis and biological evaluation of C-furanosidic and acyclic LpxC inhibitors. Eur. J. Med. Chem. 2016, 110, 340−375. (519) Diaz-Oltra, S.; Angulo-Pachon, C. A.; Murga, J.; Falomir, E.; Carda, M.; Marco, J. A. Synthesis and biological properties of the cytotoxic 14-membered macrolides aspergillide A and B. Chem. - Eur. J. 2011, 17, 675−688. (520) Diaz-Oltra, S.; Angulo-Pachon, C. A.; Murga, J.; Carda, M.; Marco, J. A. Stereoselective synthesis of the cytotoxic 14-membered macrolide aspergillide A. J. Org. Chem. 2010, 75, 1775−1778. (521) Oddo, A.; Holl, R. Design and stereoselective synthesis of a Caryl furanoside as a conformationally constrained CHIR-090 analogue. Carbohydr. Res. 2012, 359, 59−64. (522) Meng, W.; Ellsworth, B. A.; Nirschl, A. A.; McCann, P. J.; Patel, M.; Girotra, R. N.; Wu, G.; Sher, P. M.; Morrison, E. P.; Biller, S. A.; Zahler, R.; Deshpande, P. P.; Pullockaran, A.; Hagan, D. L.; Morgan, N.; Taylor, J. R.; Obermeier, M. T.; Humphreys, W. G.; Khanna, A.; Discenza, L.; Robertson, J. G.; Wang, A.; Han, S.; Wetterau, J. R.; Janovitz, E. B.; Flint, O. P.; Whaley, J. M.; Washburn, W. N. Discovery of dapagliflozin: a potent, selective renal sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor for the treatment of type 2 diabetes. J. Med. Chem. 2008, 51, 1145−1149. (523) Liu, Y.; Fu, T.; Chen, Z.; Ou, C. A new and improved process for C-aryl glucoside SGLT2 inhibitors. Monatsh. Chem. 2015, 146, 1715− 1721. (524) Sharma, G. V. M; Subash, V.; Reddy, N. Y.; Narsimulu, K.; Ravi, R.; Jadhav, V. B.; Murthy, U. S. N.; Kishore, K. H.; Kunwar, A. C. Synthesis and conformational studies of peptides from new C-linked carbo-β-amino acids (β-Caas) with anomeric methylamino- and difluorophenyl moieties. Org. Biomol. Chem. 2008, 6, 4142−4156. (525) Chen, Z.-H.; Wang, R.-W.; Qing, F.-L. Synthesis and biological evaluation of SGLT2 inhibitors: gem-difluoromethylenated dapagliflozin analogs. Tetrahedron Lett. 2012, 53, 2171−2176. (526) Yepremyan, A.; Minehan, T. G. Total synthesis of indole-3acetonitrile-4-methoxy-2-C-β-D-glucopyranoside. Proposal for structural revision of the natural product. Org. Biomol. Chem. 2012, 10, 5194− 5196. (527) Tietze, L. F.; Griesbach, U.; Schuberth, I.; Bothe, U.; Marra, A.; Dondoni, A. Novel carboranyl C-glycosides for the treatment of cancer by boron neutron capture therapy. Chem. - Eur. J. 2003, 9, 1296−1302. (528) Michelet, V.; Adiey, K.; Tanier, S.; Dujardin, G.; Genet, J. P. New aspects in the stereoselective ethynylation of β-C-glycoside aldehydes. Application to the synthesis of an ambruticin fragment. Eur. J. Org. Chem. 2003, 2003, 2947−2958. 12350


Chemical Reviews

Review

(529) Dondoni, A.; Mariotti, G.; Marra, A.; Massi, A. Expeditious synthesis of β-linked glycosyl serine methylene isosteres (β-C-Gly Ser) via ethynylation of sugar lactones. Synthesis 2001, 2001, 2129−2137. (530) Aslam, T.; Fuchs, M. G. G.; le Formal, A.; Wightman, R. H. Synthesis of C-disaccharide analogues of the α-D-arabinofuranosyl-(1→ 5)-α-D-arabinofuranosyl motif of mycobacterial cell walls via alkynyl intermediates. Tetrahedron Lett. 2005, 46, 3249−3252. (531) Yamamoto, Y.; Yamashita, K.; Hotta, T.; Hashimoto, T.; Kikuchi, M.; Nishiyama, H. Synthesis of spirocyclic C-arylglycosides and -ribosides by ruthenium-catalyzed cycloaddition. Chem. - Asian J. 2007, 2, 1388−1399. (532) Yamada, H.; Adachi, M.; Isobe, M.; Nishikawa, T. Stereocontrolled total synthesis of polygalolide A. Chem. - Asian J. 2013, 8, 1428−1435. (533) Subrahmanyam, A. V.; Palanichamy, K.; Kaliappan, K. P. Application of an enyne metathesis/Diels−Alder cycloaddition sequence: a new versatile approach to the syntheses of C-aryl glycosides and spiro-C-aryl glycosides. Chem. - Eur. J. 2010, 16, 8545−8556. (534) Narute, S. B.; Rout, J. K.; Ramana, C. V. Synthesis of Cdisaccharides through a one-pot alkynol cycloisomerization-reductive deoxygenation. Chem. - Eur. J. 2013, 19, 15109−15114. (535) Leaver, D. J.; Hughes, A. B.; Polyzos, A.; White, J. M. X-ray crystal structure determinations of galactosylacetylene building blocks. J. Carbohydr. Chem. 2010, 29, 379−385. (536) Hanessian, S.; Focken, T.; Mi, X.; Oza, R.; Chen, B.; Ritson, D.; Beaudegnies, R. Total synthesis of (+)-ambruticin S: probing the pharmacophoric subunit. J. Org. Chem. 2010, 75, 5601−5618. (537) Yamamoto, Y.; Hashimoto, T.; Hattori, K.; Kikuchi, M.; Nishiyama, H. Synthesis of spirocyclic C-arylribosides via cyclotrimerization. Org. Lett. 2006, 8, 3565−3568. (538) Dondoni, A.; Marra, A.; Mizuno, M.; Giovannini, P. P. Linear total synthetic routes to β-D-C-(1,6)-linked oligoglucoses and oligogalactoses up to pentaoses by iterative Wittig olefination assembly. J. Org. Chem. 2002, 67, 4186−4199. (539) Dondoni, A. Formylation of carbohydrates and the evolution of synthetic routes to artificial oligosaccharides and glycoconjugates. Pure Appl. Chem. 2000, 72, 1577−1588. (540) Dondoni, A.; Marra, A. Multigram scale synthesis of formyl tetraO-benzyl-β-D-C-glucopyranoside using benzothiazole as a formyl group equivalent. Tetrahedron Lett. 2003, 44, 13−16. (541) Ellsworth, B. A.; Doyle, A. G.; Patel, M.; Caceres-Cortes, J.; Meng, W.; Deshpande, P. P.; Pullockaran, A.; Washburn, W. N. CArylglucoside synthesis: triisopropylsilane as a selective reagent for the reduction of an anomeric C-phenyl ketal. Tetrahedron: Asymmetry 2003, 14, 3243−3247. (542) Dondoni, A.; Marra, A. A new synthetic approach to mycobacterial cell wall α-(1→5)-D-arabinofuranosyl C-oligosaccharides. Tetrahedron Lett. 2003, 44, 4067−4071. (543) Dondoni, A.; Formaglio, P.; Marra, A.; Massi, A. Selectivity in the SmI2-induced deoxygenation of thiazolylketoses for formyl C-glycoside synthesis and revised structure of C-ribofuranosides. Tetrahedron 2001, 57, 7719−7727. (544) Chen, C.-L.; Sparks, S. M.; Martin, S. F. C-Aryl glycosides via tandem intramolecular benzyne-furan cycloadditions. Total synthesis of vineomycinone B2 methyl ester. J. Am. Chem. Soc. 2006, 128, 13696− 13697. (545) Sparks, S. M.; Chen, C.-L.; Martin, S. F. Tandem intramolecular benzyne−furan cycloadditions. Total synthesis of vineomycinone B2 methyl ester. Tetrahedron 2007, 63, 8619−8635. (546) Apsel, B.; Bender, J. A.; Escobar, M.; Kaelin, D. E., Jr; Lopez, O. D.; Martin, S. F. General entries to C-aryl glycosides. Formal synthesis of galtamycinone. Tetrahedron Lett. 2003, 44, 1075−1077. (547) Li, H.; Procko, K.; Martin, S. F. Facile synthesis of C-aryl glycals from sugar-derived lactones. Tetrahedron Lett. 2006, 47, 3485−3488. (548) Sollogoub, M.; Fox, K. R.; Powers, V. E. C.; Brown, T. First synthesis of 1-deazacytidine, the C-nucleoside analogue of cytidine. Tetrahedron Lett. 2002, 43, 3121−3123. (549) Liu, X.; Yin, Q.; Yin, J.; Chen, G.; Wang, X.; You, Q.-D.; Chen, Y.-L.; Xiong, B.; Shen, J. Highly stereoselective nucleophilic addition of

difluoromethyl-2-pyridyl sulfone to sugar lactones and efficient synthesis of fluorinated 2-ketoses. Eur. J. Org. Chem. 2014, 2014, 6150−6154. (550) Caputo, R.; Festa, P.; Guaragna, A.; Palumbo, G.; Pedatella, S. A novel approach to the stereocontrolled synthesis of C-vinyl β-Dgalactopyranosides. Carbohydr. Res. 2003, 338, 1877−1880. (551) Caputo, R.; Ciriello, U.; Festa, P.; Guaragna, A.; Palumbo, G.; Pedatella, S. Stereoselective synthesis of fully protected (S)-1,7dioxaspiro[5,5]undec-4-ene derivatives of sugars. Eur. J. Org. Chem. 2003, 2003, 2617−2621. (552) Wellner, E.; Gustafsson, T.; Bäcklund, J.; Holmdahl, R.; Kihlberg, J. Synthesis of a C-glycoside analogue of β-D-galactosyl hydroxynorvaline and its use in immunological studies. ChemBioChem 2000, 1, 272−280. (553) Martinez-Solorio, D.; Jennings, M. P. Formal synthesis of (−)-neopeltolide featuring a highly stereoselective oxocarbenium formation/reduction sequence. J. Org. Chem. 2010, 75, 4095−4104. (554) Sharpe, R. J.; Jennings, M. P. A formal synthesis of (−)-cyanolide A featuring a stereoselective Mukaiyama Aldol reaction and oxocarbenium reduction. J. Org. Chem. 2011, 76, 8027−8032. (555) van Hooft, P. A. V.; El Oualid, F.; Overkleeft, H. S.; van der Marel, G. A.; van Boom, J. H.; Leeuwenburgh, M. A. Synthesis and elaboration of functionalised carbohydrate-derived spiroketals. Org. Biomol. Chem. 2004, 2, 1395−1403. (556) Sabitha, G.; Reddy, S. S. S.; Yadav, J. S. Total synthesis of cryptopyranmoscatone B1 from 3,4,6-tri-O-acetyl-D-glucal. Tetrahedron Lett. 2010, 51, 6259−6261. (557) Carrick, J. D.; Jennings, M. P. An efficient formal synthesis of (−)- clavosolide A featuring a "mismatched" stereoselective oxocarbenium reduction. Org. Lett. 2009, 11, 769−772. (558) Sawant, K. B.; Jennings, M. P. Efficient total syntheses and structural verification of both diospongins A and B via a common δlactone intermediate. J. Org. Chem. 2006, 71, 7911−7914. (559) Ding, F.; Jennings, M. P. Total synthesis of (−)-dactylolide and formal synthesis of (−)-zampanolide via target oriented β-C-glycoside formation. J. Org. Chem. 2008, 73, 5965−5976. (560) Jennings, M. P.; Clemens, R. T. Total synthesis of (−)-centrolobine: β-C-glycoside formation via a tandem Grignard addition and stereoselective hemi-ketal reduction. Tetrahedron Lett. 2005, 46, 2021−2024. (561) Sawant, K. B.; Ding, F.; Jennings, M. P. An efficient synthesis of the C1−C14 subunit of (−)-lasonolide A via a target oriented β-Cglycoside formation sequence. Tetrahedron Lett. 2006, 47, 939−942. (562) Sawant, K. B.; Ding, F.; Jennings, M. P. Synthesis of the C17−C25 subunit of lasonolide A utilizing a Tsuchihashi−Yamamoto type rearrangement. Tetrahedron Lett. 2007, 48, 5177−5180. (563) Knapp, S.; Yang, C.; Haimowitz, T. Addition of trialkylaluminum reagents to glyconolactones. Synthesis of 1-C-methyl GlcNAc oxazoline and thiazoline. Tetrahedron Lett. 2002, 43, 7101−7104. (564) Gouge-Ibert, V.; Pierry, C.; Poulain, F.; Serre, A.-L.; Largeau, C.; Escriou, V.; Scherman, D.; Jubault, P.; Quirion, J.-C.; Leclerc, E. Synthesis of fluorinated C-mannopeptides as sialyl Lewisx mimics for Eand P-selectin inhibition. Bioorg. Med. Chem. Lett. 2010, 20, 1957−1960. (565) Soengas, R. G. Studies on indium-mediated additions to lactones: synthesis of 2-deoxy-2-substituted-3-ulosonic acids. Tetrahedron: Asymmetry 2010, 21, 2249−2253. (566) Orsini, F.; Di Teodoro, E. A new Co(0) complex mediated synthesis of C-glycoside analogues. Tetrahedron: Asymmetry 2003, 14, 2521−2528. (567) Orsini, F.; Di Teodoro, E. New stereoselective synthesis of phosphono analogues of glycosyl phosphates. Tetrahedron: Asymmetry 2002, 13, 1307−1313. (568) Orsini, F.; Caselli, A. SmI2-mediated reactions of diethyl iodomethylphosphonate with esters and lactones: a highly stereoselective synthesis of a precursor of the C-glycosyl analogue of thymidine 5′-(β-L-rhamnosyl)diphosphate. Tetrahedron Lett. 2002, 43, 7259−7261. 12351


Chemical Reviews

Review

(569) Yang, W.-B.; Yang, Y.-Y.; Gu, Y.-F.; Wang, S.-H.; Chang, C.-C.; Lin, C.-H. Stereochemistry in the synthesis and reaction of exo-glycals. J. Org. Chem. 2002, 67, 3773−3782. (570) Caravano, A.; Vincent, S. P. Synthesis of three C-glycoside analogues of UDP-galactopyranose as conformational probes for the mutase-catalyzed furanose/pyranose interconversion. Eur. J. Org. Chem. 2009, 2009, 1771−1780. (571) Yang, W.-B.; Wu, C.-Y.; Chang, C.-C.; Wang, S.-H.; Teo, C.-F.; Lin, C.-H. Facile synthesis of conjugated exo-glycals. Tetrahedron Lett. 2001, 42, 6907−6910. (572) Caravano, A.; Mengin-Lecreulx, D.; Brondello, J.-M.; Vincent, S. P.; Sinay, P. Synthesis and inhibition properties of conformational probes for the mutase-catalyzed UDP-galactopyranose/furanose interconversion. Chem. - Eur. J. 2003, 9, 5888−5898. (573) Gascon-Lopez, M.; Motevalli, M.; Paloumbis, G.; Bladon, P.; Wyatt, P. B. C-Glycosylidene derivatives (exo-glycals): their synthesis by reaction of protected sugar lactones with tributylphosphonium ylids, conformational analysis and stereoselective reduction. Tetrahedron 2003, 59, 9349−9360. (574) Lakhrissi, Y.; Taillefumier, C.; Lakhrissi, M.; Chapleur, Y. Efficient conditions for the synthesis of C-glycosylidene derivatives: a direct and stereoselective route to C-glycosyl compounds. Tetrahedron: Asymmetry 2000, 11, 417−421. (575) Habib, S.; Larnaud, F.; Pfund, E.; Mena Barragan, T.; Lequeux, T.; Ortiz Mellet, C. O.; Goekjian, P. G.; Gueyrard, D. Synthesis of substituted exo-glucals via a modified Julia olefination and identification as selective β-glucosidase inhibitors. Org. Biomol. Chem. 2014, 12, 690− 699. (576) Bourdon, B.; Corbet, M.; Fontaine, P.; Goekjian, P. G.; Gueyrard, D. Synthesis of enol ethers from lactones using modified Julia olefination reagents: application to the preparation of tri- and tetrasubstituted exoglycals. Tetrahedron Lett. 2008, 49, 747−749. (577) Gueyrard, D.; Haddoub, R.; Salem, A.; Bacar, N. S.; Goekjian, P. G. Synthesis of methylene exoglycals using a modified Julia olefination. Synlett 2005, 520−522. (578) Gueyrard, D.; Fontaine, P.; Goekjian, P. G. Synthesis of Cglucoside endo-glycals from C-glucosyl vinyl sulfones. Synthesis 2006, 2006, 1499−1503. (579) Corbet, M.; Bourdon, B.; Gueyrard, D.; Goekjian, P. G. A Julia olefination approach to the synthesis of functionalized enol ethers and their transformation into carbohydrate-derived spiroketals. Tetrahedron Lett. 2008, 49, 750−754. (580) Waschke, D.; Thimm, J.; Thiem, J. Highly efficient synthesis of ketoheptose. Org. Lett. 2011, 13, 3628−3631. (581) Zhong, W.; Moya, C.; Jacobs, R. S.; Little, R. D. Synthesis and an evaluation of the bioactivity of the C-glycoside of pseudopterosin A methyl ether. J. Org. Chem. 2008, 73, 7011−7016. (582) Koch, S.; Schollmeyer, D.; Löwe, H.; Kunz, H. C-Glycosyl amino acids through hydroboration−cross-coupling of exo-glycals and their application in automated solid-phase synthesis. Chem. - Eur. J. 2013, 19, 7020−7041. (583) Rosenberg, H. J.; Riley, A. M.; Correa, V.; Taylor, C. W.; Potter, B. V. L C-Glycoside based mimics of D-myo-inositol 1,4,5-trisphosphate. Carbohydr. Res. 2000, 329, 7−16. (584) Woodward, H.; Smith, N.; Gallagher, T. exo-Glycals: intermediates in the synthesis of 1,1-disubstituted C-glycosides. Synlett 2010, 2010, 869−872. (585) Caravano, A.; Baillieul, D.; Ansiaux, C.; Pan, W.; Kovensky, J.; Sinay, P.; Vincent, S. P. Synthesis of galactosides locked in a 1,4B boat conformation and functionalized at the anomeric position. Tetrahedron 2007, 63, 2070−2077. (586) Schmidt, R. R.; Hoffmann, M. C-Glycosides from O-glycosyl trichloroacetimidates. Tetrahedron Lett. 1982, 23, 409−412. (587) Li, Y.; Wei, G.; Yu, B. Aryl C-glycosylation of phenols with glycosyl trifluoroacetimidates. Carbohydr. Res. 2006, 341, 2717−2722. (588) Hung, S.-C.; Wong, C.-H. Samarium diiodide mediated coupling of glycosyl phosphates with carbon radical or anion acceptors-synthesis of C-glycosides. Angew. Chem., Int. Ed. Engl. 1996, 35, 2671−2674.

(589) Stolz, F.; Blume, A.; Hinderlich, S.; Reutter, W.; Schmidt, R. R. C-Glycosidic UDP-GlcNAc analogues as inhibitors of UDP-GlcNAc 2epimerase. Eur. J. Org. Chem. 2004, 2004, 3304−3312. (590) Tram, K.; MacIntosh, W.; Yan, H. Synthesis of glycosyl dipyrromethanes. Tetrahedron Lett. 2009, 50, 2278−2280. (591) Adero, P. O.; Furukawa, T.; Huang, M.; Mukherjee, D.; Retailleau, P.; Bohe, L.; Crich, D. Cation clock reactions for the determination of relative reaction kinetics in glycosylation reactions: applications to gluco- and mannopyranosyl sulfoxide and trichloroacetimidate type donors. J. Am. Chem. Soc. 2015, 137, 10336−10345. (592) Huang, M.; Retailleau, P.; Bohe, L.; Crich, D. Cation clock permits distinction between the mechanisms of α- and β-O- and β-Cglycosylation in the mannopyranose series: evidence for the existence of a mannopyranosyl oxocarbenium ion. J. Am. Chem. Soc. 2012, 134, 14746−14749. (593) Shie, J.-J.; Chen, C.-A.; Lin, C.-C.; Ku, A. F.; Cheng, T.-J. R.; Fang, J. M.; Wong, C.-H. Regioselective synthesis of di-C-glycosylflavones possessing anti-inflammation activities. Org. Biomol. Chem. 2010, 8, 4451−4462. (594) Wiebe, C.; Schlemmer, C.; Weck, S.; Opatz, T. Sweet (hetero)aromatics: glycosylated templates for the construction of saccharide mimetics. Chem. Commun. 2011, 47, 9212−9214. (595) Herzner, H.; Palmacci, E. R.; Seeberger, P. H. Short total synthesis of 8,10-di-O-methylbergenin. Org. Lett. 2002, 4, 2965−2967. (596) Weck, S.; Opatz, T. β-Selective C-mannosylation of electronrich phenols. Synthesis 2010, 2010, 2393−2398. (597) Furuta, T.; Kimura, T.; Kondo, S.; Mihara, H.; Wakimoto, T.; Nukaya, H.; Tsuji, K.; Tanaka, K. Concise total synthesis of flavone Cglycoside having potent anti-inflammatory activity. Tetrahedron 2004, 60, 9375−9379. (598) Plante, O. J.; Palmacci, E. R.; Andrade, R. B.; Seeberger, P. H. Oligosaccharide synthesis with glycosyl phosphate and dithiophosphate triesters as glycosylating agents. J. Am. Chem. Soc. 2001, 123, 9545− 9554. (599) Palmacci, E. R.; Seeberger, P. H. Synthesis of C-aryl and C-alkyl glycosides using glycosyl phosphates. Org. Lett. 2001, 3, 1547−1550. (600) Hashimoto, Y.; Tanikawa, S.; Saito, R.; Sasaki, K. βStereoselective mannosylation using 2,6-lactones. J. Am. Chem. Soc. 2016, 138, 14840−14843. (601) Noel, A.; Delpech, B.; Crich, D. Stereoselective, electrophilic αC-sialidation. Org. Lett. 2012, 14, 1342−1345. (602) Singh, G.; Vankayalapati, H. Efficient stereocontrolled synthesis of C-glycosides using glycosyl donors substituted by propane 1,3-diyl phosphate as the leaving group. Tetrahedron: Asymmetry 2001, 12, 1727−1735. (603) Palmacci, E. R.; Plante, O. J.; Seeberger, P. H. Oligosaccharide synthesis in solution and on solid support with glycosyl phosphates. Eur. J. Org. Chem. 2002, 2002, 595−606. (604) Hosomi, A.; Sakata, Y.; Sakurai, H. Highly stereoselective Callylation of glycopyranosides with allylsilanes catalyzed by silyl triflate or iodosilane. Tetrahedron Lett. 1984, 25, 2383−2386. (605) Sandbhor, M.; Bhasin, M.; Williams, D. T.; Hsieh, M.; Wu, S.-H.; Zou, W. Synthesis of iminoalditol analogues of galactofuranosides and their activities against glycosidases. Carbohydr. Res. 2008, 343, 2878− 2886. (606) Zhu, C.-J.; Yi, H.; Chen, G.-R.; Xie, J. Synthesis of novel photolabile glycosides from methyl 4,6-O-(o-nitro)benzylidene-α-Dglycopyranosides. Tetrahedron 2008, 64, 10687−10693. (607) Rainier, J. D.; Allwein, S. P.; Cox, J. M. C-Glycosides to fused polycyclic ethers. A formal synthesis of (±)-hemibrevetoxin B. J. Org. Chem. 2001, 66, 1380−1386. (608) Wu, A.-T.; Yi, T.; Shao, H.; Wu, S.-H.; Zou, W. Stereoselective synthesis of dioxabicycles from 1-C-allyl-2-O-benzyl-glycosides − An intramolecular cyclization between 2-O-benzyl oxygen and the allyl double bond. Can. J. Chem. 2006, 84, 597−602. (609) Roberts, S. W.; Rainier, J. D. Synthesis of an A-E gambieric acid subunit with use of a C-glycoside centered strategy. Org. Lett. 2007, 9, 2227−2230. 12352


Chemical Reviews

Review

2-C-branched glycals: formal total synthesis of (−)-brevisamide. Eur. J. Org. Chem. 2014, 2014, 8085−8093. (635) Godage, H. Y.; Chambers, D. J.; Evans, G. R.; Fairbanks, A. J. Stereoselective synthesis of C-glycosides from carboxylic acids: the tandem Tebbe−Claisen approach. Org. Biomol. Chem. 2003, 1, 3772− 3786. (636) Sridhar, P. R.; Sudharani, C. Stereoselective synthesis of C-2methylene and C-2-methyl-C-glycosides by Claisen rearrangement of 2vinyloxymethyl glycals. RSC Adv. 2012, 2, 8596−8598. (637) Chambers, D. J.; Evans, G. R.; Fairbanks, A. J. Synthesis of Cglycosyl amino acids: scope and limitations of the tandem Tebbe/ Claisen approach. Tetrahedron: Asymmetry 2005, 16, 45−55. (638) Godage, H. Y.; Fairbanks, A. J. Stereoselective synthesis of Cglycosides via Tebbe methylenation and Claisen rearrangement. Tetrahedron Lett. 2000, 41, 7589−7593. (639) Godage, H. Y.; Fairbanks, A. J. Synthesis of α-C-glycosides via tandem Tebbe methylenation and Claisen rearrangement. Tetrahedron Lett. 2003, 44, 3631−3635. (640) Chambers, D. J.; Evans, G. R.; Fairbanks, A. J. An approach to the synthesis of α-(1−6)-C-disaccharides by tandem Tebbe methylenation and Claisen rearrangement. Tetrahedron 2005, 61, 7184−7192. (641) Wallace, G. A.; Scott, R. W.; Heathcock, C. H. Synthesis of the C29-C44 portion of spongistatin 1 (altohyrtin A). J. Org. Chem. 2000, 65, 4145−4152. (642) Colombo, L.; di Giacomo, M.; Ciceri, P. Practical stereoselective synthesis of α-D-C-mannosyl-(R)-alanine. Tetrahedron 2002, 58, 9381− 9386. (643) Hirai, G.; Watanabe, T.; Yamaguchi, K.; Miyagi, T.; Sodeoka, M. Stereocontrolled and convergent entry to CF2-sialosides: synthesis of CF2-linked ganglioside GM4. J. Am. Chem. Soc. 2007, 129, 15420− 15421. (644) Sodeoka, M.; Hirai, G.; Watanabe, T.; Miyagi, T. A strategy for constructing C-sialosides based on Ireland−Claisen rearrangement and its application for synthesis of CF2-linked ganglioside GM4 analog. Pure Appl. Chem. 2009, 81, 205−215. (645) Pasetto, P.; Franck, R. W. Synthesis of both possible isomers of the northwest quadrant of Altromycin B. J. Org. Chem. 2003, 68, 8042− 8060. (646) Yang, G.; Franck, R. W.; Bittman, R.; Samadder, P.; Arthur, G. Synthesis and growth inhibitory properties of glucosamine-derived glycerolipids. Org. Lett. 2001, 3, 197−200. (647) Paterson, D. E.; Griffin, F. K.; Alcaraz, M.-L.; Taylor, R. J. K. A Ramberg−Bäcklund approach to the synthesis of C-glycosides, C-linked disaccharides, and C-glycosyl amino acids. Eur. J. Org. Chem. 2002, 2002, 1323−1336. (648) Taylor, R. J. K.; McAllister, G. D.; Franck, R. W. The Ramberg− Bäcklund reaction for the synthesis of C-glycosides, C-linkeddisaccharides and related compounds. Carbohydr. Res. 2006, 341, 1298−1311. (649) Ohnishi, Y.; Ichikawa, Y. Stereoselective synthesis of a Cglycoside analogue of N-Fmoc-serine β-N-acetylglucosaminide by Ramberg−Bäcklund rearrangement. Bioorg. Med. Chem. Lett. 2002, 12, 997−999. (650) Pasetto, P.; Chen, X.; Drain, C. M.; Franck, R. W. Synthesis of hydrolytically stable porphyrin C- and S-glycoconjugates in high yields. Chem. Commun. 2001, 81−82. (651) Tomooka, K.; Yamamoto, H.; Nakai, T. Stereoselective synthesis of highly functionalized C-glycosides based on acetal [1,2] and [1,4] Wittig rearrangements. Angew. Chem., Int. Ed. 2000, 39, 4500− 4502. (652) Dixon, D. J.; Ley, S. V.; Tate, E. W. Diastereoselective oxygen to carbon rearrangements of anomerically linked enol ethers and the total synthesis of (+)-(S,S)-(cis-6-methyltetrahydropyran-2-yl)acetic acid, a component of civet. J. Chem. Soc., Perkin Trans. 1 2000, 2385−2394. (653) Buffet, M. F.; Dixon, D. J.; Edwards, G. L.; Ley, S. V.; Tate, E. W. Oxygen to carbon rearrangements of anomerically linked alkenols from tetrahydropyran derivatives: an investigation of the reaction mechanism via a double isotopic labelling crossover study. J. Chem. Soc., Perkin Trans. 1 2000, 1815−1827.

(610) Walter, A.; Westermann, B. Facile synthesis of building blocks for C-glycosidic neoglycoconjugates. Synlett 2000, 2000, 1682−1684. (611) Duchek, J.; Huang, M.-H.; Vasella, A. Towards stable di-carba analogues of guanofosfocins. Tetrahedron Lett. 2011, 52, 2940−2942. (612) Girard, C.; Miramon, M.-L.; de Solminihac, T.; Herscovici, J. Synthesis of 3-C-(6-O-acetyl-2,3,4-tri-O-benzyl-α-D-mannopyranosyl)1-propene: a caveat. Carbohydr. Res. 2002, 337, 1769−1774. (613) Yi, T.; Wu, S.-H.; Zou, W. Synthesis of C-5-thioglycopyranosides and their sulfonium derivatives from 1-C-(2′-oxoalkyl)-5-S-acetylglycofuranosides. Carbohydr. Res. 2005, 340, 235−244. (614) Mari, S.; Canada, F. J.; Jimenez-Barbero, J.; Bernardi, A.; Marcou, G.; Motto, I.; Velter, I.; Nicotra, F.; La Ferla, B. Synthesis and conformational analysis of galactose-derived bicyclic scaffolds. Eur. J. Org. Chem. 2006, 2006, 2925−2933. (615) Beignet, J.; Tiernan, J.; Woo, C. H.; Kariuki, B. M.; Cox, L. R. Stereoselective synthesis of allyl-C-mannosyl compounds: use of a temporary silicon connection in intramolecular allylation strategies with allylsilanes. J. Org. Chem. 2004, 69, 6341−6356. (616) Saleh, T.; Rousseau, G. Preparation and reactions of 2-allyl-5deoxymannose derivatives. Tetrahedron 2002, 58, 2891−2897. (617) Jarikote, D. V.; O’Reilly, C.; Murphy, P. V. Ultrasound-assisted synthesis of C-glycosides. Tetrahedron Lett. 2010, 51, 6776−6778. (618) Wipf, P.; Pierce, J. G. Expedient synthesis of the α-C-glycoside analogue of the immunostimulant galactosylceramide (KRN7000). Org. Lett. 2006, 8, 3375−3378. (619) Boto, A.; Hernandez, D.; Hernandez, R.; Alvarez, E. Coupling radical and ionic processes: an unusual rearrangement affords sugar and C-glycoside derivatives. Eur. J. Org. Chem. 2009, 2009, 3853−3857. (620) Löpfe, M.; Siegel, J. S. Diastereoselective synthesis of 2′,3′dideoxy-β-C-glucopyranosides as intermediates for the synthesis of 2′,3′-dideoxy-β-D-glucopyranosyl-C-nucleosides. Nucleosides, Nucleotides Nucleic Acids 2007, 26, 1029−1035. (621) Brimble, M. A.; Davey, R. M.; McLeod, M. D. Synthesis of azido analogues of medermycin. Synlett 2002, 1318−1322. (622) Brimble, M. A.; Davey, R. M.; McLeod, M. D.; Murphy, M. Synthesis of 3-azido-2,3,6-trideoxy-β-D-arabino-hexopyranosyl pyranonaphthoquinone analogues of medermycin. Org. Biomol. Chem. 2003, 1, 1690−1700. (623) Hainke, S.; Arndt, S.; Seitz, O. Concise synthesis of aryl-Cnucleosides by Friedel−Crafts alkylation. Org. Biomol. Chem. 2005, 3, 4233−4238. (624) Wu, K.; Wang, M.; Yao, Q.; Zhang, A. Synthesis study toward mayamycin. Chin. J. Chem. 2013, 31, 93−99. (625) Barta, J.; Slavetinska, L.; Klepetarova, B.; Hocek, M. Modular synthesis of 5-substituted furan-2-yl C-2′-deoxyribonucleosides and biaryl covalent base-pair analogues. Eur. J. Org. Chem. 2010, 2010, 5432−5443. (626) Caneque, T.; Gomes, F.; Mai, T. T.; Maestri, G.; Malacria, M.; Rodriguez, R. Synthesis of marmycin A and investigation into its cellular activity. Nat. Chem. 2015, 7, 744−751. (627) Caneque, T.; Gomes, F.; Mai, T. T.; Blanchard, F.; Retailleau, P.; Gallard, J.-F.; Maestri, G.; Malacria, M.; Rodriguez, R. A synthetic study towards the marmycins and analogues. Synthesis 2017, 49, 587−592. (628) Tulshian, D. B.; Fraser-Reid, B. Routes to C-glycopyranosides via sigmatropic rearrangements. J. Org. Chem. 1984, 49, 518−522. (629) Werschkun, B.; Thiem, J. Claisen rearrangements in carbohydrate chemistry. Top. Curr. Chem. 2001, 215, 293−325. (630) Taylor, R. J. K. Recent developments in Ramberg−Bäcklund and episulfone chemistry. Chem. Commun. 1999, 217−227. (631) Griffin, F. K.; Murphy, P. V.; Paterson, D. E.; Taylor, R. J. K. A Ramberg−Bäcklund approach to exo-glycals. Tetrahedron Lett. 1998, 39, 8179−8182. (632) Belica, P. S.; Franck, R. W. Benzylic C-glycosides via the Ramberg−Bäcklund reaction. Tetrahedron Lett. 1998, 39, 8225−8228. (633) Grindley, T. B.; Wickramage, C. A novel approach to the synthesis of C-glycosyl compounds: the Wittig rearrangement. J. Carbohydr. Chem. 1988, 7, 661−685. (634) Sudharani, C.; Venukumar, P.; Sridhar, P. R. Stereoselective synthesis of C-2-methylene and C-2-methyl α- and β-C-glycosides from 12353


Chemical Reviews

Review

sustainable oxidation reactions. Beilstein J. Org. Chem. 2015, 11, 280− 287. (675) Gruttadauria, M.; Aprile, C.; Lo Meo, P.; Riela, S.; Noto, R. Diastereoselective synthesis of substituted 2-phenyltetrahydropyrans as useful precursors of aryl C-glycosides via selenoetherification. Heterocycles 2004, 63, 681−690. (676) Qian, Y.; Feng, J.; Parvez, M.; Ling, C.-C. Unexpected anomeric selectivity of a 1-C-arylglycal donor in Kdo glycoside synthesis. J. Org. Chem. 2012, 77, 96−107. (677) Liu, C.-F.; Xiong, D.-C.; Ye, X.-S. "Ring opening−ring closure” strategy for the synthesis of aryl-C-glycosides. J. Org. Chem. 2014, 79, 4676−4686. (678) Hartung, J.; Schmidt, P. Vanadium(V)-catalyzed stereoselective synthesis of functionalized disubstituted tetrahydrofurans. Synlett 2000, 2000, 367−370. (679) Hartung, J.; Drees, S.; Greb, M.; Schmidt, P.; Svoboda, I.; Fuess, H.; Murso, A.; Stalke, D. (Schiff-base)vanadium(V) complex-catalyzed oxidations of substituted bis(homoallylic) alcohols − stereoselective synthesis of functionalized tetrahydrofurans. Eur. J. Org. Chem. 2003, 2003, 2388−2408. (680) Hartung, J.; Greb, M. Transition metal-catalyzed oxidations of bishomoallylic alcohols. J. Organomet. Chem. 2002, 661, 67−84. (681) Sharma, G. V. M; Chander, S.; Krishna, P. R. Pd(II)-mediated synthesis of 2-deoxy- and rare-C-glycosides. Tetrahedron: Asymmetry 2001, 12, 539−544. (682) Moral, J. A.; Moon, S.-J.; Rodriguez-Torres, S.; Minehan, T. G. A sequential indium-mediated aldehyde allylation/palladium-catalyzed cross-coupling reaction in the synthesis of 2-deoxy-β-C-aryl glycosides. Org. Lett. 2009, 11, 3734−3737. (683) Wolfe, J. P.; Hay, M. B. Recent advances in the stereoselective synthesis of tetrahydrofurans. Tetrahedron 2007, 63, 261−290. (684) Acetti, D.; Brenna, E.; Gatti, F. G. Oxygenated stereotriads with definite absolute configuration by lipase-mediated kinetic resolution: de novo synthesis of imino sugars and 6-deoxy-C-glycosides. Eur. J. Org. Chem. 2010, 2010, 4468−4475. (685) Acetti, D.; Brenna, E.; Fuganti, C.; Gatti, F. G.; Malpezzi, L.; Serra, S. Synthesis of L- and D-4,6-dideoxyhexoses and 4,6-dideoxy-Cphenylglycosides from enzyme-generated products. Eur. J. Org. Chem. 2008, 2008, 5125−5134. (686) Fernandez de la Pradilla, R. F.; Manzano, P.; Montero, C.; Priego, J.; Martinez-Ripoll, M.; Martinez-Cruz, L. A. Nucleophilic epoxidation of α′-hydroxy dienyl sulfoxides. J. Org. Chem. 2003, 68, 7755−7767. (687) Ravarino, E.; Jana, S. K.; Fröhlich, R.; Holl, R. Stereocontrolled synthesis of four diastereomeric C-aryl manno- and talofuranosides. Carbohydr. Res. 2012, 361, 162−169. (688) Yan, L.; Dai, G.-F.; Yang, J.-L.; Liu, F.-W.; Liu, H.-M. Synthesis of furanosyl α-C-glycosides derived from 4-chloro-4-deoxy-α-D-galactose and their cytotoxic activities. Bioorg. Med. Chem. Lett. 2007, 17, 3454− 3457. (689) Patel, P.; Ramana, C. V. Total synthesis of (−)-isatisine A. J. Org. Chem. 2012, 77, 10509−10515. (690) Sharma, G. V. M; Raman Kumar, K.; Sreenivas, P.; Radha Krishna, P.; Chorghade, M. S. Catalytic FeCl3- or Yb(OTf)3-mediated synthesis of substituted tetrahydrofurans and C-aryl glycosides from 1,4diols. Tetrahedron: Asymmetry 2002, 13, 687−690. (691) Takase, M.; Morikawa, T.; Abe, H.; Inouye, M. Stereoselective synthesis of alkynyl C-2-deoxy-β-D-ribofuranosides via intramolecular nicholas reaction: a versatile building block for nonnatural Cnucleosides. Org. Lett. 2003, 5, 625−628. (692) Wohland, M.; Maier, M. E. 2,6-Disubstituted tetrahydropyrans by domino Meyer−Schuster rearrangement−hetero-Michael addition of 6-alkyne-1,5-diols. Synlett 2011, 2011, 1523−1526. (693) Radha Krishna, P.; Lavanya, B.; Sharma, G. V. M Stereoselective synthesis of C-phenyl D- and L-glycero heptopyranosides. Tetrahedron: Asymmetry 2003, 14, 419−427. (694) Izquierdo, I.; Plaza, M. T.; Robles, R.; Mota, A. J. 4-Octulose derivatives, prepared from l-sorbose, as key intermediates in the

(654) Buffet, M. F.; Dixon, D. J.; Ley, S. V.; Reynolds, D. J.; Storer, R. I. Anomeric oxygen to carbon rearrangements of alkynyl tributylstannane derivatives of furanyl (γ)- and pyranyl (δ)-lactols. Org. Biomol. Chem. 2004, 2, 1145−1154. (655) Dixon, D. J.; Ley, S. V.; Reynolds, D. J.; Chorghade, M. S. A short and efficient stereoselective synthesis of the potent 5-lipoxygenase inhibitor CMI-977. Synth. Commun. 2000, 30, 1955−1961. (656) Maziarz, E.; Furman, B. Acid catalyzed rearrangement of vinyl and ketene acetals. Tetrahedron 2014, 70, 1651−1658. (657) Pougny, J.-R.; Nassr, M. A. M.; Sinay, P. Mercuricyclisation in carbohydrate chemistry: a highly stereoselective route to α-D-Cglucopyranosyl derivatives. J. Chem. Soc., Chem. Commun. 1981, 375− 376. (658) Danishefsky, S. J.; Pearson, W. H.; Harvey, D. F.; Maring, C. J.; Springer, J. P. Chelation-controlled facially selective cyclocondensation reactions of chiral alkoxy aldehydes: syntheses of a mouse androgen and of a carbon-linked disaccharide. J. Am. Chem. Soc. 1985, 107, 1256− 1268. (659) Harvey, J. E.; Hewitt, R. J.; Moore, P. W.; Somarathne, K. K. Reactions of 1,2-cyclopropyl carbohydrates. Pure Appl. Chem. 2014, 86, 1377−1399. (660) Aucagne, V.; Tatibouët, A.; Rollin, P. Thermodynamics versus kinetics in hetero-Michael cyclizations: a highly stereoselective approach to access both epimers of a C-D-mannopyranoside. Tetrahedron Lett. 2008, 49, 4750−4753. (661) Wen, X.; Hultin, P. G. Concise and stereocontrolled syntheses of phosphonate C-glycoside analogues of β-D-ManNAc and β-D-GlcNAc 1O-phosphates. Tetrahedron Lett. 2004, 45, 1773−1775. (662) Vakalopoulos, A.; Hoffmann, H. M. R. Versatile 8oxabicyclo[3.2.1]oct-6-en-3-one: stereoselective methodology for generating C-glycosides, δ-valerolactones, and polyacetate segments. Org. Lett. 2001, 3, 177−180. (663) Redon, S.; Wierzbicki, M.; Prunet, J. A new oxa-Michael reaction and a gold-catalysed cyclisation en route to C-glycosides. Tetrahedron Lett. 2013, 54, 2089−2092. (664) Harvey, J. E.; Raw, S. A.; Taylor, R. J. K. A versatile and stereocontrolled route to pyranose and furanose C-glycosides. Org. Lett. 2004, 6, 2611−2614. (665) Yakushiji, F.; Maddaluno, J.; Yoshida, M.; Shishido, K. Diastereoselective construction of substituted tetrahydropyrans using an intramolecular oxy-Michael strategy. Tetrahedron Lett. 2009, 50, 1504−1506. (666) Toumieux, S.; Compain, P.; Martin, O. R. Intramolecular metalcatalyzed amination of pseudo-anomeric C−H bonds. Tetrahedron Lett. 2005, 46, 4731−4735. (667) Nolen, E. G.; Ezeh, V. C.; Feeney, M. J. Highly stereoselective synthesis of C-vinyl pyranosides via a Pd0-mediated cycloetherification of 1-acetoxy-2,3-dideoxy-oct-2-enitols. Carbohydr. Res. 2014, 396, 43− 47. (668) Notz, W.; Hartel, C.; Waldscheck, B.; Schmidt, R. R. De novo synthesis of a methylene-bridged Neu5Ac-α-(2,3)-Gal C-disaccharide. J. Org. Chem. 2001, 66, 4250−4260. (669) Khodair, A. I.; Schmidt, R. R. Synthesis of C-glycosyl compounds of N-acetylneuraminic acid from D-gluconolactone. Carbohydr. Res. 2002, 337, 1967−1978. (670) Marcotte, S.; D’Hooge, F.; Ramadas, S.; Feasson, C.; Pannecoucke, X.; Quirion, J.-C. Synthesis of new α- and β-gemdifluoromethylene C-glycosides in the galactose and glucose series. Tetrahedron Lett. 2001, 42, 5879−5882. (671) Brimble, M. A.; Pavia, G. S.; Stevenson, R. J. A facile synthesis of aryldihydropyrans using a Sonogashira−selenoetherification strategy. Tetrahedron Lett. 2002, 43, 1735−1738. (672) Xu, G.; Moeller, K. D. Anodic coupling reactions and the synthesis of C-glycosides. Org. Lett. 2010, 12, 2590−2593. (673) Smith, J. A.; Moeller, K. D. Oxidative cyclizations, the synthesis of aryl-substituted C-glycosides, and the role of the second electron transfer step. Org. Lett. 2013, 15, 5818−5821. (674) Nguyen, B. H.; Perkins, R. J.; Smith, J. A.; Moeller, K. D. Photovoltaic-driven organic electrosynthesis and efforts toward more 12354


Chemical Reviews

Review

stereoselective Ssynthesis of C-glycoside and polyhydroxyindolizidine analogues. Eur. J. Org. Chem. 2000, 2000, 2071−2078. (695) Sengoku, T.; Arimoto, H.; Uemura, D. Synthetic approach to kendomycin: preparation of the C-glycosidic core. Chem. Commun. 2004, 1220−1221. (696) Sarabia, F.; Chammaa, S.; Lopez Herrera, F. J. Synthesis of 2deoxy-α-DAH based on diazo chemistry by insertion reactions of 2diazo-3-deoxy-D-arabino-heptulosonate derivatives mediated by rhodium(II). Tetrahedron 2001, 57, 10271−10279. (697) Harding, M.; Nelson, A. A general, two-directional synthesis of C-(1→6)-linked disaccharide mimetics: synthesis from non-carbohydrate based starting materials. Chem. Commun. 2001, 695−696. (698) Harding, M.; Hodgson, R.; Majid, T.; McDowall, K. J.; Nelson, A. A stereodivergent, two-directional synthesis of stereoisomeric Clinked disaccharide mimetics. Org. Biomol. Chem. 2003, 1, 338−349. (699) Hay, M. B.; Hardin, A. R.; Wolfe, J. P. Palladium-catalyzed synthesis of tetrahydrofurans from γ-hydroxy terminal alkenes: scope, limitations, and stereoselectivity. J. Org. Chem. 2005, 70, 3099−3107. (700) Yadav, J. S.; Krishnam Raju, A.; Sunitha, V. Highly stereoselective synthesis of C-(alkynyl)-pseudoglycals from δ-hydroxy-α,βunsaturated aldehydes. Tetrahedron Lett. 2006, 47, 5269−5272. (701) Hans, S.; Altiti, A.; Mootoo, D. R. Synthesis of the C-glycoside of α-D-mannose-(1→6)-D-myo-inositol. Org. Biomol. Chem. 2013, 11, 6952−6959. (702) Kumaran, G.; Mootoo, D. R. Synthesis of KDO and analogues from a novel mannose-derived precursor. Tetrahedron Lett. 2001, 42, 3783−3785. (703) Denton, R. W.; Mootoo, D. R. Synthesis of the C-glycoside of methyl α-D-altropyranosyl-(1→4)-α-D-glucopyranoside. J. Carbohydr. Chem. 2003, 22, 671−683. (704) Augustin, L. A.; Fantini, J.; Mootoo, D. R. C-Glycoside analogues of β-galactosylceramide with a simple ceramide substitute: synthesis and binding to HIV-1 gp120. Bioorg. Med. Chem. 2006, 14, 1182−1188. (705) Hans, S. K.; Camara, F.; Altiti, A.; Martin-Montalvo, A.; Brautigan, D. L.; Heimark, D.; Larner, J.; Grindrod, S.; Brown, M. L.; Mootoo, D. R. Synthesis of C-glycoside analogues of β-galactosamine(1→4)-3-O-methyl-dchiro-inositol and assay as activator of protein phosphatases PDHP and PP2Cα. Bioorg. Med. Chem. 2010, 18, 1103− 1110. (706) Cheng, X.; Khan, N.; Mootoo, D. R. Synthesis of the C-glycoside analogue of a novel sialyl Lewis X mimetic. J. Org. Chem. 2000, 65, 2544−2547. (707) Tony, K. A.; Denton, R. W.; Dilhas, A.; Jimenez-Barbero, J.; Mootoo, D. R. Synthesis of β-C-galacto-pyranosides with fluorine on the pseudoanomeric substituent. Org. Lett. 2007, 9, 1441−1444. (708) Postema, M. H. D.; Piper, J. L.; Betts, R. L.; Valeriote, F. A.; Pietraszkewicz, H. RCM-based synthesis of a variety of β-C-glycosides and their in vitro anti-solid tumor activity. J. Org. Chem. 2005, 70, 829− 836. (709) Postema, M. H. D.; Piper, J. L.; Betts, R. L. Synthesis of stable carbohydrate mimetics as potential glycotherapeutics. Synlett 2005, 1345−1358. (710) Liu, L.; Postema, M. H. D. Unified approach to differentially linked β-C-disaccharides by ring-closing metathesis. J. Am. Chem. Soc. 2001, 123, 8602−8603. (711) Postema, M. H. D.; Calimente, D.; Liu, L.; Behrmann, T. L. An olefin metathesis route for the preparation of (1→6)-linked Cdisaccharide glycals. A convergent and flexible approach to C-saccharide synthesis. J. Org. Chem. 2000, 65, 6061−6068. (712) Postema, M. H. D.; Piper, J. L.; Liu, L.; Shen, J.; Faust, M.; Andreana, P. Synthesis and partial biological evaluation of a small library of differentially-linked β-C-disaccharides. J. Org. Chem. 2003, 68, 4748− 4754. (713) Piper, J. L.; Postema, M. H. D. First Synthesis of a branched β-Ctetrasaccharide using a triple ring closing metathesis cyclization. J. Org. Chem. 2004, 69, 7395−7398. (714) Postema, M. H. D.; Piper, J. L. Synthesis of some biologically relevant β-C-glycoconjugates. Org. Lett. 2003, 5, 1721−1723.

(715) Chaulagain, M. R.; Postema, M. H. D.; Valeriote, F.; Pietraszkewicz, H. Synthesis and anti-tumor activity of β-C-glycoside analogs of the immunostimulant KRN7000. Tetrahedron Lett. 2004, 45, 7791−7794. (716) Schmidt, B.; Wildemann, H. A synthesis of densely functionalized 2,3-dihydropyrans using ring-closing metathesis and base-induced rearrangements of dihydropyran oxides. Eur. J. Org. Chem. 2000, 2000, 3145−3163. (717) Schmidt, B. A de novo synthesis of 2,6-dideoxy-C-aryl glycosides based on ring closing metathesis and diastereoselective epoxide cleavage/anomerization reactions. Org. Lett. 2000, 2, 791−794. (718) Evans, P. A.; Lawler, M. J. Regio- and diastereoselective rhodium-catalyzed allylic substitution with acyclic α-alkoxy-substituted copper(I) enolates: stereodivergent approach to 2,3,6-trisubstituted dihydropyrans. J. Am. Chem. Soc. 2004, 126, 8642−8643. (719) Mondal, D.; Schweizer, F. Alkylation reactions using a galactosebased β-keto ester enolate and conversion into β-C-galactosides. Synlett 2008, 2008, 2475−2478. (720) Vijayasaradhi, S.; Aidhen, I. S. Umpolung strategy for the synthesis of 2-deoxy-C-aryl glycosides: a serendipitous, efficient route for C-furanoside analogues. Org. Lett. 2002, 4, 1739−1742. (721) Evans, P. A.; Cui, J.; Gharpure, S. J. Stereoselective construction of cis-2,6-disubstituted tetrahydropyrans via the reductive etherification of δ-trialkylsilyloxy substituted ketones: total synthesis of (−)-centrolobine. Org. Lett. 2003, 5, 3883−3885. (722) Evans, P. A.; Cui, J.; Gharpure, S. J.; Hinkle, R. J. Stereoselective construction of cyclic ethers using a tandem two-component etherification: elucidation of the role of bismuth tribromide. J. Am. Chem. Soc. 2003, 125, 11456−11457. (723) Guillarme, S.; Ple, K.; Haudrechy, A. Selective synthesis of α-C(alkynyl)-galactosides by an efficient tandem reaction. J. Org. Chem. 2006, 71, 1015−1017. (724) Karche, N. P.; Pierry, C.; Poulain, F.; Oulyadi, H.; Leclerc, E.; Pannecoucke, X.; Quirion, J.-C. Synthesis of β-CF2-D-mannopyranosides and β-CF2-D-galactopyranosides by Reformatsky addition onto 5ketohexoses. Synlett 2007, 2007, 123−126. (725) Leclerc, E.; Pannecoucke, X. Synthetic efforts towards the synthesis of fluorinated C-glycosidic analogues of α-galactosylceramides. C. R. Chim. 2012, 15, 57−67. (726) Kandziora, M.; Mucha, E.; Zucker, S. P.; Reissig, H.-U. Syntheses of mono- and divalent C-aminoglycosides using 1,2-oxazine chemistry and olefin metathesis. Synlett 2015, 26, 367−374. (727) Kandziora, M.; Reissig, H.-U. Synthesis of rigid p-terphenyllinked carbohydrate mimetics. Beilstein J. Org. Chem. 2014, 10, 1749− 1758. (728) Patil, R. S.; Ahire, K. M.; Ramana, C. V. Stereospecific synthesis of C-arabinofuranosides and carba-disaccharide analogues of Motif C of cell wall AG complex of Mtb. Tetrahedron Lett. 2012, 53, 6347−6350. (729) Potopnyk, M. A.; Cmoch, P.; Cieplak, M.; Gajewska, A.; Jarosz, S. The synthesis of higher carbon sugars: a study on the rearrangement of higher sugar allylic alcohols. Tetrahedron: Asymmetry 2011, 22, 780− 786. (730) Bahnck, K. B.; Rychnovsky, S. D. Formal synthesis of (−)-kendomycin featuring a Prins-cyclization to construct the macrocycle. J. Am. Chem. Soc. 2008, 130, 13177−13181. (731) Maingot, L.; Vu, N. Q.; Collet, S.; Guingant, A.; Martel, A.; Dujardin, G. [4 + 2]/HyBRedOx approach to C-naphthyl glycosides: failure in the projuglone series and reinvestigation of the HyBRedOx sequence. Eur. J. Org. Chem. 2009, 2009, 412−422. (732) Stepanek, P.; Vich, O.; Werner, L.; Kniezo, L.; Dvorakova, H.; Vojtisek, P. Stereoselective preparation of precursors of α-C-(1→3)disaccharides. Collect. Czech. Chem. Commun. 2005, 70, 1411−1428. (733) Gong, J.; Bonfand, E.; Brown, E.; Dujardin, G.; Michelet, V.; Genet, J.-P. Remarkable stereocontrol in the synthesis of 1,2,3,5tetrasubstituted tetrahydropyrans via an asymmetric heterocycloaddition of a ketone-derived enol ether. Tetrahedron Lett. 2003, 44, 2141− 2144. 12355


Chemical Reviews

Review

conversion of D-fructose into 2,2,5-trisubstituted tetrahydrofurans. Tetrahedron 2002, 58, 3629−3637. (755) Hernandez-Garcia, L.; Quintero, L.; Höpfl, H.; Sosa, M.; SartilloPiscil, F. Inverse stereoselectivity in the nucleophilic attack on fivemembered ring oxocarbenium ions. Application to the total synthesis of 7-epi-(+)-goniofufurone. Tetrahedron 2009, 65, 139−144. (756) Sanchez-Eleuterio, A.; Quintero, L.; Sartillo-Piscil, F. High 1,3trans stereoselectivity in nucleophilic substitution at the anomeric position and β-fragmentation of the primary alkoxyl radical in 3-amino3-deoxy-ribofuranose derivatives: application to the synthesis of 2-epi(−)-jaspine B. J. Org. Chem. 2011, 76, 5466−5471. (757) Chen, X.; Wang, Q.; Yu, B. Gold(I)-catalyzed C-glycosylation of glycosyl ortho-alkynylbenzoates: the role of the moisture sequestered by molecular sieves. Chem. Commun. 2016, 52, 12183−12186. (758) Zhu, F.; Rourke, M. J.; Yang, T.; Rodriguez, J.; Walczak, M. A. Highly stereospecific cross-coupling reactions of anomeric stannanes for the synthesis of C-aryl glycosides. J. Am. Chem. Soc. 2016, 138, 12049− 12052. (759) Wenger, W.; Vasella, A. Glycosylidene carbenes part 29). Insertion into B−C and Al−C bonds: glycosylborinates, -boranes, and -alanes. Helv. Chim. Acta 2000, 83, 1542−1560. (760) Boultadakis-Arapinis, M.; Prost, E.; Gandon, V.; Lemoine, P.; Turcaud, S.; Micouin, L.; Lecourt, T. Carbene-mediated functionalization of the anomeric C−H bond of carbohydrates: scope and limitations. Chem. - Eur. J. 2013, 19, 6052−6066. (761) Boultadakis-Arapinis, M.; Lemoine, P.; Turcaud, S.; Micouin, L.; Lecourt, T. Rh(II) carbene-promoted activation of the anomeric C-H bond of carbohydrates: a stereospecific entry toward α- and βketopyranosides. J. Am. Chem. Soc. 2010, 132, 15477−15479. (762) Wardrop, D. J.; Zhang, W.; Fritz, J. Stereospecific entry to [4.5]spiroketal glycosides using alkylidenecarbene C−H insertion. Org. Lett. 2002, 4, 489−492. (763) Frihed, T. G.; Bols, M.; Pedersen, C. M. C−H functionalization on carbohydrates. Eur. J. Org. Chem. 2016, 2016, 2740−2756. (764) DeShong, P.; Soli, E. D.; Slough, G. A.; Sidler, D. R.; Elango, V.; Rybczynski, P. J.; Vosejpka, L. J. S.; Lessen, T. A.; Le, T. X.; Anderson, G. B.; von Philipsborn, W.; Vö hler, M.; Rentsch, D.; Zerbe, O. Glycosylmanganese pentacarbonyl complexes: an organomanganesebased approach to the synthesis of C-glycosyl derivatives. J. Organomet. Chem. 2000, 593−594, 49−62. (765) Jahjah, R.; Gassama, A.; Bulach, V.; Suzuki, C.; Abe, M.; Hoffmann, N.; Martinez, A.; Nuzillard, J.-M. Stereoselective tripletsensitised radical reactions of furanone derivatives. Chem. - Eur. J. 2010, 16, 3341−3354. (766) Brunckova, J.; Crich, D. Intramolecular hydrogen atom abstraction: the β-oxygen effect in the Norrish type II photoreaction. Tetrahedron 1995, 51, 11945−11952. (767) Hoffmann, H. M. R.; Dunkel, R.; Mentzel, M.; Reuter, H.; Stark, C. B. W. The total synthesis of C-glycosides with completely resolved seven-carbon backbone polyol stereochemistry: stereochemical correlations and access to L-configured and other rare carbohydrates. Chem. Eur. J. 2001, 7, 4771−4789. (768) Hartung, I. V.; Hoffmann, H. M. R. 8-Oxabicyclo[3.2.1]oct-6en-3-ones: application to the asymmetric synthesis of polyoxygenated building blocks. Angew. Chem., Int. Ed. 2004, 43, 1934−1949. (769) Carrel, F.; Vogel, P. Total synthesis of a protected form of 2,6anhydro-5-azido-3,5-dideoxy-2-C-hydroxymethyl-L-allo-heptose; a potential precursor of analogs of C-glycosides of neuraminic acid. Tetrahedron: Asymmetry 2000, 11, 4661−4680.

(734) Kommana, P.; Chung, S. W.; Donaldson, W. A. Synthetic studies directed toward amphidinol 2: elucidation of the relative configuration of the C1−C10 fragment. Tetrahedron Lett. 2008, 49, 6209−6211. (735) Himanen, J. A.; Pihko, P. M. Synthesis of trisaccharides by hetero-Diels−Alder welding of two monosaccharide units. Eur. J. Org. Chem. 2012, 2012, 3765−3780. (736) Wan, Q.; Lubineau, A.; Guillot, R.; Scherrmann, M.-C. Synthesis of C-disaccharides via a hetero-Diels−Alder reaction and further stereocontrolled transformations. Carbohydr. Res. 2008, 343, 1754− 1765. (737) Pachamuthu, K.; Schmidt, R. R. Diels−Alder reaction of 2-nitro glycals: a new route to the synthesis of benzopyrans. Synlett 2003, 2003, 1355−1357. (738) Oh, J.; Lee, C. R.; Chun, K. H. A short synthesis of bicyclic sugar pyrimidine nucleosides from C-glycosides. Tetrahedron Lett. 2001, 42, 4879−4881. (739) Sanhueza, C. A.; Mayato, C.; Machin, R. P.; Padron, J. M.; Dorta, R. L.; Vazquez, J. T. Cytotoxic effects of C-glycosides in HOS and HeLa cell lines. Bioorg. Med. Chem. Lett. 2007, 17, 3676−3681. (740) Oh, J.; Lee, C.-R.; Chun, K. H. A one-pot convenient procedure for the synthesis of C-glycoside via cycloaddition of dichloroketene to glycal and dechlorination of the cycloadduct. Synth. Commun. 2002, 32, 2349−2353. (741) Moore, P. W.; Schuster, J. K.; Hewitt, R. J.; Stone, M. R. L.; Teesdale-Spittle, P. H.; Harvey, J. E. Divergent synthesis of 2-Cbranched pyranosides and oxepines from 1,2-gem-dibromocyclopropyl carbohydrates. Tetrahedron 2014, 70, 7032−7043. (742) Gremyachinskiy, D. E.; Samoshin, V. V.; Gross, P. H. Total synthesis of aminomethyl-C-dideoxyglycopyranosides and their quinamides. Tetrahedron Lett. 2003, 44, 6587−6590. (743) Rajasekaran, P.; Mallikharjunarao, Y.; Vankar, Y. D. Synthesis of 1C-aryl/alkyl 2C-branched sugar-fused isochroman derivatives by sequential Prins and Friedel−Crafts cyclizations on a Perlin aldehyde derived substrate. Synlett 2017, 28, 1346−1352. (744) Redpath, P.; Ness, K. A.; Rousseau, J.; Macdonald, S. J. F.; Migaud, M. E. Facile access to new C-glycosides and C-glycoside scaffolds incorporating functionalised aromatic moieties. Carbohydr. Res. 2015, 402, 25−34. (745) Lowe, J. T.; Panek, J. S. Stereocontrolled [4 + 2]-annulation accessing dihydropyrans: synthesis of the C1a-C10 fragment of kendomycin. Org. Lett. 2005, 7, 1529−1532. (746) Lee, Y. J.; Baek, J. Y.; Lee, B.-Y.; Kang, S. S.; Park, H.-S.; Jeon, H. B.; Kim, K. S. 2′-Carboxybenzyl glycosides: glycosyl donors for Cglycosylation and conversion into other glycosyl donors. Carbohydr. Res. 2006, 341, 1708−1716. (747) Rousseau, C.; Martin, O. R. Stereodirected synthesis of aryl α-Cglycosides from 2-O-arylsilyl-glucopyranosides. Org. Lett. 2003, 5, 3763−3766. (748) Kudelsk, W. Synthesis of C-glycosides from S-glycosyl phosphorothioates. Z. Naturforsch. B 2002, 57, 243−247. (749) Berry, C. R.; Rameshkumar, C.; Tracey, M. R.; Wei, L.-L.; Hsung, R. P. A Lewis acid mediated stereoselective removal of an anomeric urea substituent. Synlett 2003, 791−796. (750) Rameshkumar, C.; Hsung, R. P. Pyranyl heterocycles from inverse electron demand hetero [4 + 2] cycloaddition reactions of chiral allenamides as a new chiral template for constructing C-glycoside substrates. Synlett 2003, 2003, 1241−1246. (751) Henschke, J. P.; Wu, P.-Y.; Lin, C.-W.; Chen, S.-F.; Chiang, P. C.; Hsiao, C.-N. β-Selective C-arylation of silyl protected 1,6-anhydroglucose with arylalanes: the synthesis of SGLT2 inhibitors. J. Org. Chem. 2015, 80, 2295−2309. (752) Hager, D.; Paulitz, C.; Tiebes, J.; Mayer, P.; Trauner, D. Total synthesis of herbicidin C and aureonuclemycin: impasses and new avenues. J. Org. Chem. 2013, 78, 10784−10801. (753) Friestad, G. K.; Lee, H. J. Trans-2,5-disubstituted tetrahydrofurans via addition of carbon nucleophiles to the strained bicyclic acetal 2,7dioxabicyclo[2.2.1]heptane. Org. Lett. 2009, 11, 3958−3961. (754) Goursaud, F.; Peyrane, F.; Veyrieres, A. New synthesis of 2,6anhydro-β-D-fructofuranoses, pivotal [2.2.1] bicyclic acetals for the 12356


Recent Advances in the Chemical Synthesis of C-Glycosides

Recommend Documents