Chiral Monophosphorus Ligands for Asymmetric Catalytic Reactions

Review pubs.acs.org/acscatalysis

Chiral Monophosphorus Ligands for Asymmetric Catalytic Reactions Wenzhen Fu and Wenjun Tang* 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: Chiral monophosphorus ligands are playing an important role for the recent advances in asymmetric catalysis. This review summarizes the latest progress in various asymmetric catalytic reactions with the employment of chiral monophosphorus ligands including asymmetric allylic substitution, asymmetric dearomative arylation, asymmetric Heck reaction, asymmetric cross-coupling, asymmetric C−H bond functionalization, asymmetric coupling of π systems, asymmetric addition, asymmetric hydrogenation, and asymmetric organocatalytic reactions. The new reactivity, selectivity, and reaction mechanism enabled by these chiral monophosphorus ligands are discussed.

KEYWORDS: chiral monophosphorus ligands, asymmetric allylic substitution, asymmetric dearomative arylation, asymmetric cross-coupling, asymmetric C−H bond functionalization, asymmetric addition, asymmetric hydrogenation, asymmetric organocatalysis

1. INTRODUCTION

such as 1,1′-binaphthyls, BINOLs, TADDOLs, spiro structures, and others, have been more developed and explored (Scheme 2). There have been several reviews on applications of chiral monophosphorus ligands.4d,k,7 To avoid redundancy, this review covers the progress achieved in the past decade by using chiral monophosphorus ligands, and the chemistry related to P,N-type and P,olefin-type ligands will not be discussed. Advances in both transition-metal-catalyzed asymmetric reactions and organocatalysis enabled by chiral monophosphorus ligands will be discussed with particular emphasis on reactivity, selectivity, and mechanisms.

One of the most challenging tasks in current organic synthesis is to develop efficient methods of accessing enantiomerically pure compounds from readily available starting materials. Among various synthetic methods, asymmetric catalysis is most attractive. The development of efficient chiral catalysts/ligands has played an important role in the field of asymmetric catalysis.1 In particular, significant progress has been made in the development and application of chiral bidentate ligands in asymmetric catalysis.2 This is mainly due to the relatively well-defined catalyst structure associated with chiral bidentate ligands leading to excellent enantiomeric differentiation.3 In contrast, the chiral monodentate ligands were neglected and underdeveloped. Their applications were less described. Only recently, their uniqueness and advantages were explored and shown in various catalytic reactions thanks to the development of several excellent chiral monophosphorus ligands.4 Historically, the monophosphorus ligands were among the earliest to be explored in asymmetric catalysis. In the early 1970s, Knowles5 reported the Rh-catalyzed asymmetric hydrogenation of dehydroamino acids, and up to 88% ee was achieved by using a P-chiral monophosphorus ligand CAMP. Morrison6 developed NMDPP, and it provided a 61% ee in Rh-catalyzed hydrogenation of (E)-β-methylcinnamic acid. These early examples signified the advent of chiral monophosphorus ligands, and this decade has witnessed the rapid development of the field. The chiral monophosphorus ligands can be arbitrarily classified into two categories, P-chiral ligands and backbone-chiral ligands. The P-chiral ligands are limited due to their relative synthetic difficulties (Scheme 1). The backbone-chiral ligands, which are equipped with some well-known chiral frameworks © 2016 American Chemical Society

2. ALLYLIC SUBSTITUTION Transition-metal-catalyzed asymmetric allylic substitution8 has attracted considerable attention owing to its versatile synthetic utilities and mechanistic interests. The substitution on a π-allylic metal intermediate can lead to various issues including reactivity, regioselectivity, diasteroselectivity, and enantioselectvity. Ligand design and substrate selection are the keys to solve these issues. The high activity observed with chiral monophosphoramide ligands has enabled tremendous progress in the field with the development of several interesting and efficient reactions. 2.1. Asymmetric Dearomative Allylation. Aromatic compounds are common chemical feedstocks readily available from petroleum chemistry. Their activation and utilization in organic synthesis have gained much interest. The catalytic asymmetric dearomatization (CADA) reaction of aromatic compounds has become one of the most interesting transformations to produce chiral molecules in a very efficient manner. The chiral monophosphoramidite Received: April 6, 2016 Revised: June 3, 2016 Published: June 9, 2016 4814

DOI: 10.1021/acscatal.6b01001 ACS Catal. 2016, 6, 4814−4858

Review

ACS Catalysis Scheme 1. Representative P-Chiral Monophosphorus Ligands

Scheme 2. Representative Chiral Monophosphorus Ligands with Backbone Chirality

In 2010, You and co-workers10 reported a highly enantioselective Ir-catalyzed intramolecular C-3 allylic alkylation of indoles

ligands have enabled a number of efficient asymmetric dearomative allylations.9 4815


Review

ACS Catalysis with monophosphoramidite (R,Ra)-L29 as the ligand to form a series of spiroindolenine derivatives in excellent yields with up to 99/1 dr and 97% ee. A 2-substituted indolyl allyl carbonate was applicable to provide product 3 with a moderate dr. The formation of spiroindolenine 3 as the six-membered cyclic product at the C-3 position was favorable over the seven-membered cyclic product at the C-2 position (Scheme 3).

Scheme 5. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation of Pyrroles

Scheme 3. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation of Indoles

revealed that the nucleophilic attack of the indole ring at the C-3 position was favorable. A subsequent acid-catalyzed migration proceeded through a three-center two-electron pathway to form the observed product with the retention of the stereochemistry (Scheme 6). Interestingly, the migration group switched under the basic condition. You and co-workers14 reported an Ir-catalyzed intramolecular asymmetric allylic dearomatization/migration/aromatization reaction of indoles with chiral monophosphoramidite (Ra)-L31 as the ligand and products 12 were isolated in good to excellent yields with up to 99% ee’s (Scheme 7). Besides electron-rich arenes, electron-deficient arenes were also suitable substrates. In 2014, You and co-workers15 achieved the direct asymmetric dearomative allylation of pyridines and pyrazines without preactivation. The acidic Ha was in situ deprotonated, forming an electron-rich intermediate. With chiral monophosphoramidite (S,S,Sa)-L30 and (R,Ra)-L29 as ligands, chiral 2,3-dihydroindolizine and 6,7-dihydropyrrolo[1,2-α]pyrazine derivatives were obtained in good to excellent yields with high enantioselectivities under mild reaction conditions (Scheme 8). For the intramolecular asymmetric dearomative allylation of aromatic compounds, branched allylic products were produced preferentially because of the formation of the 5/6-membered rings. Control of the regioselectivity in an intermolecular reaction is much challenging. Using chiral monophosphoramidite (S,S,Sa)-L30 as the ligand, You and co-workers16 reported an Ir-catalyzed intermolecular regio- and enantioselective dearomative allylation of 2-hydroxypyridine with a catalytic amount of base. The desired chiral N-allylation products 21 were formed in good to excellent yields with up to 99% ee. Studies showed that other reaction pathways such as O-allylation/rearrangement and rapid reversed reaction of the O-allylation product were unlikely to be involved (Scheme 9). Substitution on the pyrrole ring took place either at C-2 or C-3 position when different reaction conditions were applied.14,17 Additionally, the (π-allyl)Ir complex C1 was isolated and its X-ray crystal structure revealed the occurrence of a phenyl C(sp2)−H bond activation18 (Scheme 10). The You group19 also reported an Ir-catalyzed intermolecular diastereo- and enantioselective allylic alkylation of 3-substituted indoles followed by a intramolecular cyclization and the desired chiral product 32 was obtained in a moderate to excellent yield with up to >20/1 dr and up to 99% ee. The chiral monophosphoramidite ligand (R,Ra)L29 proved to be crucial for the high regio-, diastereo-, and enantioselectivities (Scheme 11).

A year later, You and co-workers11 expanded the Ir-catalyzed intramolecular dearomative allylations to phenol substrates. With (S,S,Sa)-L30 as the ligand, the reaction formed the substituted 5/6-membered cyclic spirocyclohexadienone derivatives 5 with up to 97% ee and moderate to excellent yields (Scheme 4). Scheme 4. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation of Phenols

Ir-catalyzed intramolecular asymmetric dearomative allylation of pyrroles was also accomplished by You and co-workers12 using similar reaction conditions. The spiro-2H-pyrrole derivatives with 6-membered aza-rings were generated in good yields with up to >99/1 dr and 96% ee’s. However, only a trace amount of the corresponding product was observed when a carbon-tethered substrate was employed (Scheme 5). In 2012, the same group also reported the five-membered cyclic spiroindolenines by Ir-catalyzed asymmetric intramolecular dearomative allylation of indoles with chiral monophoporamidite (S,S,Sa)-L14 as the ligand.13 A series of 2,3,4,9tetrahydro-1H-carbazoles were formed in good yields and up to 97% ee by using a catalytic amount of acid. DFT calculation 4816


Review

ACS Catalysis Scheme 6. Ir-Catalyzed Intramolecular Allylic Dearomatization/Migration of Indoles

followed by hydrolysis, leading to the formation of 34.20 The employment of an aromatic group in compound 33 was thought to stabilize the iminium cation of the intermediate T9 and help enhancing the yield of 34 (Scheme 12). To understand the mechanism of Ir-catalyzed asymmetric dearomative allylation of quinone 35, You and co-workers21 carried out some experiments to differentiate the reaction pathways between path a and path b. The results indicated that path b was more plausible, although path a could not be completely ruled out (Scheme 13). For the substrate 37 bearing a phosphate leaving group, the dearomatized product 36 was obtained in 67% yield and 42% ee under standard conditions. The results seemed to support the existence of path b, because the base in the reaction system was not strong enough to deprotonate Ha in the substrate (Scheme 14a). In addition, the quinolinium intermediate T13/T14 in path b was indirectly proved by the isolation of dearomatization/hydrogenation products 39 and 41 under standard conditions (Scheme 14b,c). These results indicated that the deprotonation of Ha might occur after the N-attack process.

Scheme 7. Ir-Catalyzed Intramolecular Allylic Dearomatization/Migration/Aromatization of Indoles

The spiroindolenines obtained by Ir-catalyzed intramolecular asymmetric dearomative allylation of 2,3-disubstituted indoles decomposed on silica gel to form chiral tryptamine derivatives. An intermediate T9 was formed by a retro-Mannich reaction

Scheme 8. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation of Pyridines and Pyrazines

4817


Review

ACS Catalysis Scheme 9. Ir-Catalyzed Intermolecular Asymmetric Dearomative Allylation of 2-Hydroxypyridines

Scheme 10. Ir-Catalyzed Intramolecular Asymmetric Allylic Dearomatization/Migration/Aromatization Reaction of Pyrroles

Scheme 11. Ir-Catalyzed Intermolecular Diastereo- and Enantioselective Dearomative Allylation of 3-Substituted Indoles Followed by Cyclization

Scheme 12. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation of 2,3-Disubstituted Indoles Followed by Retro-Mannich/Hydrolysis

Using chiral monophosphoramidite L14 as the ligand, Trost and co-workers22 developed an intermolecular Pd-catalyzed dearomative trimethylenemethane (TMM) [3 + 2] cycloaddition of simple nitroarene substrates with a moderate enantioselectivity (Scheme 15). Recently, You and co-workers23 reported that the asymmetric synthesis of indole-annulated medium-sized-ring compounds through an iridium-catalyzed intramolecular allylic dearomatization/retro-Mannich/hydrolysis cascade reaction using chiral monophosphoramite L30 as ligand. The medium-sized-rings were obtained in good yields and excellent ee’s. The proposed allylic dearomatization process was supported by isolating 48, the reducing product of the intermediate T15 (Scheme 16). 2.2. Asymmetric Allylic Substitution with Carbon Nucleophiles. Besides the aromatic π systems, various soft

carbon nucleophiles are applicable for allylic substitution. The development of chiral monophosphorus ligands has enabled significant processes in this area. In 1996, Zhang and co-workers24 designed a chiral monophosphorus ligand L33 with a rigid bicyclic [2.2.1] ring. Excellent enantioselectivities were achieved in the palladium-catalyzed asymmetric allylic alkylations with dimethyl malonate as the nucelophile (Scheme 17). 4818


Review

ACS Catalysis Scheme 13. Mechanism of Asymmetric Dearomative Allylation of Quinone

Scheme 14. Supporting Experiments

In 1997, Hayashi and co-workers25 reported a Pd-catalyzed alkylations of 1-phenylallyl acetate (52) with dimethyl malonate using (Ra)-MeO-MOP (L13) as the ligand, and the branched product 54 was obtained in good regioselectivity and enantioselectivity. Furthermore, the chiral monophosphorus ligand L13 played a key role for the high branched selectivity. The steric bulkiness of the MOP ligand only allowed a single ligand to coordinate to the metal center and dimethyl malonate attacked preferentially the C-1 carbon to give the branched isomer due to a trans effect (Scheme 18). Iridium catalysts complexed with chiral monophosphoramidite ligands are very effective in controlling the regioselectivity of allylic substitution to form branched allylic isomers due to

Scheme 15. Pd-Catalyzed Dearomative TMM Cycloaddition

4819


Review

ACS Catalysis

Scheme 16. Ir-Catalyzed Intramolecular Asymmetric Dearomative Allylation Followed by Retro-Mannich/Hydrolysis To Synthesize Indole-Annulated Medium-Sized-Ring Compounds

Scheme 17. Pd-Catalyzed Asymmetric Allylic Alkylation Reported by Zhang

Scheme 19. Ir-Catalyzed Asymmetric Allylic Alkylation with TMS Enolates and Enamines as Nucleophiles

Scheme 18. Pd-Catalyzed Asymmetric Allylic Alkylation Reported by Hayashi

Scheme 20. Ir-Catalyzed Asymmetric Allylic Alkylation with Trimethylsilyloxyfurans

the electronic effect. Hartwig and co-workers reported the asymmetric Ir-catalyzed intermolecular allylic alkylation with ketone enolates26 (Scheme 19a) and enamines27 (Scheme 19b) in excellent yields, branched/linear selectivities, and enantioselectivities. The isolated iridium complex C2 was applicable as the catalyst for allylic alkylation. The enamine nucleophiles provided better yields and enantioselectivities than TMS enolates for aliphatic ketone derivatives. With trimethylsiloxyfurans as nucleophiles and complex C3 as the catalyst precursor, the Hartwig group28 realized the Ir-catalyzed asymmetric allylic substitution to form the branched product 64 with two contiguous chiral centers in moderate yields and excellent ee’s. The byproduct 65 was formed by a subsequent Cope rearrangement. The additive ZnF2 was believed to activate the reaction by releasing the acetate anion, which further activated the trimethylsilyloxyfuran substrate (Scheme 20).

The Hartwig group29 successfully expanded this methodology by employing various silyl enolates derived from a range of ketones (Table 1). With various prochiral carbon nucleophiles and proper choices of the counterions,30 cations,31 and bases,32 the metallacyclic iridium phosphoramidite complexes enabled the Ir-catalyzed 4820


Review

ACS Catalysis Table 1. Ir-Catalyzed Asymmetric Allylic Substitution with Silyl Enolates Reported by Hartwig

allylic alkylation with α-substituted benzyl nitrile was developed (Scheme 22b).37 2.3. Asymmetric Allylic Substitution with Heteroatom Nucleophiles. Transition-metal-catalyzed asymmetric allylic substitution with nitrogen, oxygen, and sulfur nucleophiles was one of most important methods to form carbon−heteroatom bonds with stereogenic centers. The Ir-catalyzed asymmetric allylic substitution was most effective by using chiral monophosphoramidites as ligands with a broad substrate scope. In 2002, Hartwig and co-workers38 reported the first regio- and enantioselective allylic amination of achiral allylic esters catalyzed by an irdium-monophosphoramidite complex in high yields (Scheme 23). The catalysts of iridium and chiral monophosphoramidite ligands were effective in asymmetric allylic aminations,38,39 etherifications,40 and sulfonations41 of achiral allylic esters and alcohols. The results were summarized in Table 3. Intramolecular allylic aminations and etherifications catalyzed by palladium42/iridium43 catalysts complexed with chiral monophosphoramidites were also achieved. In 2011, Feringa and co-workers43b reported the Ir-catalyzed intramolecular allylic amidation to synthesize chiral nitrogen-containing heterocycles such as tetrahydroisoquinolines in excellent yields and enantioselectivities (Scheme 24a). An Ir-catalyzed intramolecular allylic substitution attacked by an amide oxygen atom43a was

allylic alkylations to form a series of products with two contiguous chiral centers in excellent regio-, diastereo-, and enantioselecitivities (Table 2). Copper-catalyzed asymmetric allylic alkylation of di/trisubstituted allylic substrates with organometallic reagents has become a powerful alternative to the aforementioned Ir catalysis. In 2012, Feringa and co-workers33 reported the Cu-catalyzed allylic alkylation of di/trisubstituted allylic bromides and chlorides with primary/secondary alkyl organolithium reagents as the nucleophiles. Moderate to good b/l selectivities and enantioselectivities were achieved by using several chiral monophosphoramidite ligands (Scheme 21a). The allylic alkylation of disubstituted allylic bromides with simple allyl Grignard reagents also provided moderate to good b/l selectivities and enantioselectivities by using (S,S,Ra)-L14 as the ligand34 (Scheme 21b). Most (Z)-trisubstituted allyl bromides35 were also suitable substrates, except for the ortho-substituted aryl (Z)-allyl bromides which were unreactive possibly due to steric hindrance (Scheme 21c). By using TADDOL-derived monophosphoramidite ligands, the palladium-catalyzed asymmetric allylic alkylations of cyclic substrates with dialkylzinc reagents were also developed in good to excellent diastereoselectivities and yields, and moderate to good enantioselectivities (Scheme 22a).36 With a chiral monophosphite ligand (Ra)-L16, a highly enantioselective rhodium-catalyzed 4821


Review

ACS Catalysis Table 2. Ir-Catalyzed Asymmetric Allylic Substitution with Prochiral Nucleophiles

3. ASYMMETRIC DEAROMATIVE ARYLATION Transition-metal-catalyzed asymmetric intramolecular dearomative arylation9,48 is one of the most efficient methods to construct polycyclic compounds bearing chiral quaternary centers. However, only a few examples of intramolecular dearomative arylation were reported mainly by Buchwald,49 Bedford,50 You,10−17,19−21,51 Trost,22 and Tang.52 Their asymmetric versions were even rare. This was in contrast to the rapid development of asymmetric allylic dearomatization where a number of efficient transformations were developed mainly by You.10−17,19−21 In 2012, You and co-workers51a reported the intramolecular Pd-catalyzed dearomative arylation of 3-substituted indoles to form a series of spiroindolenines bearing a quaternary center at the C-3 position. Although the enantioselectivity of the reaction was moderate, the successful formation of product 93a demonstrated that chiral monophosphorus ligands were potentially effective for such cyclizations (Scheme 26). An intramolecular Pd-catalyzed asymmetric dearomative arylation of 5-hydroxylindolines was reported in a moderate yield and promising enantioselectivity51b with a TADDOLderived chiral monophosphoramidite (S,S,R,R)-L21 as the ligand (Scheme 27).

also accomplished to form a 6-membered cyclic product (Scheme 24b). Scheidt and co-workers42a reported a palladiumcatalyzed intramolecular allylic etherification with a TADDOLderived chiral monophosphoramidite (S,S)-L40 as the ligand, forming a series of 2-aryl-chromenes in good yields and enantioselectivities. The involvement of an achiral intermediate trans-o-quinone methide (o-QM) was proposed (Scheme 24c). 2.4. Mechanistic Consideration of Asymmetric Allylic Substitution. The mechanistic studies of catalytic asymmetric allylic substitution led to the discovery of some activated catalysts,39a,44 the development of several chiral monophosphoramidite ligands,45 and the resting state of the catalysts.29c,46 These progresses were reviewed by Hartwig8a in 2010. Studies on allylic amination showed that the enantiomeric branched allylic amines can coordinate with a metallacyclic iridium catalyst with various binding constants.46 These data indicated that the metallacyclic iridium catalyst should be selective to react with one enantiomer of a racemic branched allylic ester to form the product with high enantiomeric excess. In 2010, Hartwig and co-workers47 developed efficient methods for Ir-catalyzed kinetic asymmetric allylic substitution of racemic aliphatic and aromatic allylic benzoates with good to excellent enantioselectivities (Scheme 25). 4822


Review

ACS Catalysis Scheme 21. Cu-Catalyzed Asymmetric Allylic Alkylation with Organometallic Reagents

Scheme 22. Pd/Rh-Catalyzed Asymmetric Allylic Alkylation

phenols to construct a series of chiral tricyclic phenanthrenone derivatives bearing all-carbon quaternary centers in excellent enantioselectivities (Scheme 28a). A stereochemical model was proposed to rationalize this catalytic transformation. The stereochemistry was determined during the reductive elimination step. The 2,5-diphenylpyrrole moisty of (S)-L7 blocked the backside of the complex and the bulky tert-butyl group dictated the orientation of the substrate. The two major conformers T17A and T17B was believed to exist when substrate 96a coordinated to the Pd/(S)-L7 complex. Conformer T17B seemed to be more strained than conformer T17A (Scheme 28b). The method was successfully applied to a concise synthesis of the antimicrobial diterpene totaradiol and triptoquinone H53 (Scheme 28c).

Scheme 23. Ir-Catalyzed Asymmetric Allylic Amination of Allylic Esters

Excellent enantioselectivities were achieved by Tang and coworkers52 on asymmetric dearomative arylation of phenol. Using a P-chiral biaryl monophosphorus ligand (S)-L7, they developed an enantioselective Pd-catalyzed dearomative cyclization of substituted

4. ASYMMETRIC HECK REACTION The asymmetric Heck reaction has become one of the most important carbon−carbon bond-forming reactions and has 4823


Review

ACS Catalysis Table 3. Ir-Catalyzed Asymmetric Allylic Aminations, Etherifications, and Sulfonations

allylic sub

Nu

ligand

additive

results

ref

63a

BnNH2

(R,R,Ra)-L14

-

38

63a

BnNH2

C2

-

83a

BnNH2

(R)-L37

Nb(OEt)5

63a 63a

CF3CONHK LiNBoc2

(R)-L38 (R)-L38

-

63a

BocNH2

C3

-

63a

PhONa

(R,R,Ra)-L14

-

63a

PhSO2Na

C4

-

98/2 b/l 84%, 95% ee 98/2 b/l 81%, 95% ee 96/4 b/l 72%, 93% ee 68%, 94% ee 93/7 b/l 82%, 93% ee 96/4 b/l 85%, 99% ee 97/3 b/l 76%, 84% ee 97/3 b/l 95%, 91% ee

39a 39d 39e 39e 39f 40a 41a

Scheme 24. Intramolecular Asymmetric Allylic Substitution with N-, and O-Nucleophiles

been successfully applied for construction of chiral tertiary or quaternary carbon centers with excellent enantioselectivity. Its mechanism, catalyst selection, scope, regio- and enantioselectivities, and applications were reviewed.54 A variety of chiral bidentate ligands were developed to affect the asymmetric Heck reaction, and chiral BINAP was most employed. In contrast, examples of the asymmetric Heck reaction affected by chiral monophosphorus ligands were limited. In 2002, Feringa and co-workers55 reported a Pd-catalyzed asymmetric intramolecular Heck reaction of cyclohexadienone with a TADDOL-derived

chiral monophosphoramidite ligand in up to 96% ee (Scheme 29a). Study of the leaving group at the aryl moiety showed that the iodide substrate was more reactive than bromide and triflate substrates. A ligand/Pd ratio of 2/1 was necessary for a best enantioselectivity. Studies indicated that the intramolecular Heck reaction was likely to proceed with neutral palladium species through a syn-insertion/epimerization sequence56 (Scheme 29b). An asymmetric intramolecular Heck reaction was used to synthesize a chromium π-complex with a planar chirality. Uemura and co-workers57 developed an asymmetric Heck reaction of a 4824


Review

ACS Catalysis

5. ASYMMETRIC CROSS-COUPLING REACTION The enantioselective carbon−carbon bond-forming reaction is one of the most important transformations in organic chemistry. In particular, transition-metal-catalyzed asymmetric crosscoupling reactions59 have increasingly played a major role in constructing chiral molecules in organic synthesis. Reactivity and selectivity remain the challenging issues in the field of crosscoupling. The key to solve these problems is rational design of new chiral ligands and catalysts. Recently, chiral monophosphorus ligands have taken an increasingly major role for the new development. Herein, we summarize the recent advances in asymmetric cross-coupling reaction with chiral monophosphorus ligands. 5.1. Asymmetric C(sp2)−C(sp2) Cross-Coupling Reaction. The transition-metal-catalyzed asymmetric C(sp2)−C(sp2) cross-coupling reaction is one of most efficient and ideal methods for constructing biaryl skeletons with axial chirality, which exist in numerous natural products and drugs. In 1988, Hayashi et al.60 reported an efficient asymmetric nickel-catalyzed cross-coupling to form chiral 1,1′-binaphthyls in up to 95% ee. The chiral monophosphorus ligand (Sc,Rp)-PPFOMe (L26) was found to be more effective than diphosphine ligands (Scheme 32a). By using an electron-rich monophosphorus ligand (Sp)-L43 with only planner chirality, a Pd-catalyzed Suzuki−Miyaura crosscoupling was reported to give the same product with a moderate ee61 (Scheme 32b). Asymmetric Suzuki−Miyaura cross-coupling was also applied to establish quaternary stereocenters or planner chiral arenemetal complexes by desymmetrization. In 2004, Wills and co-workers62 reported a Pd-catalyzed enantioselective Suzuki− Miyaura cross-coupling with a chiral monophosphorus ligand (Sa)-MeO-MOP (L13) to form product 110 with a quaternary stereocenter in up to 86% ee. Both para- and meta-substituted arylboronic acids were suitable with good enantioselectivities (Scheme 33a). With a chiral monophosphoramidite (R,R,Sa)L14 as the ligand, the prochiral chromium complex 111 was successfully desymmetrized by a Suzuki−Miyaura crosscoupling.63 An array of aryl-, vinyl-, and alkylboronic acids were applicable to give coupling products with good to excellent ee’s (Scheme 33b). Modification of chiral monophosphorus ligands can increase the efficiency of asymmetric Suzuki−Miyaura cross-coupling and allow the reaction to proceed at very low catalyst loadings. Introduction of a well-organized array of aromatic rings in the structure of the phosphonate ligand (Sa)-L44 enhanced its activity for asymmetric Suzuki−Miyaura cross-coupling of aryl chlorides with arylboronic acids. The biaryl product was obtained in 75% yield and 76% ee at 0.1 mol % Pd loading64 (Scheme 34a). A chiral monophosphate ligand L45 derived from a deoxycholic acid backbone was applied in asymmetric Suzuki−Miyaura crosscoupling to provide the biaryl product 116a at 1 mol % Pd loading with a Pd:ligand ratio of 1:165 (Scheme 34b). Considerable efforts have been taken to expand the substrate scope of Pd-catalyzed asymmetric Suzuki−Miyaura cross-coupling. A range of functionalized biaryl compounds were prepared in high yields and excellent enantioselectivities with the development of chiral monophosphorus ligands. Functional groups such as phosphonate,66 carbonyl benzooxazolidinone,66b phosphine oxides,67 and formyl moieties67,68 were successfully introduced and compatible (Scheme 35a). Weak interactions such as π−π interaction and H−metal interaction between the functional groups and the other coupling partner or the metal center are important for

Scheme 25. Ir-Catalyzed Kinetic Asymmetric Allylic Substitution of Racemic Allyl Benzoates

Scheme 26. Pd-Catalyzed Asymmetric Dearomative Arylation of 3-Substituted Indoles

Scheme 27. Pd-Catalyzed Asymmetric Dearomative Arylation of 5-Hydroxylindoline

prochiral (arene)chromium complex to form the corresponding bicyclic chromium complex in up to 73% ee with chiral monophosphoramidite ligand (Sa)-L15 (MonoPhos) as the ligand (Scheme 30). An enantiomerically enriched chiral 3,3-disubstituted piperidones was synthesized through an asymmetric intramolecular Heck reaction of carbamoyl chlorides from a well-designed substrate, and the product was further transformed to an indole alkaloid (−)-epieburnamonine58 (Scheme 31). The chiral monophosphoramidite ligand (R,R,Ra)-L14 showed better enantioselective control than bidentate ligands employed, albeit with 43% ee. 4825


Review

ACS Catalysis Scheme 28. Pd-Catalyzed Asymmetric Dearomative Arylation of Substituted Phenols

Scheme 29. Asymmetric Intramolecular Heck Reaction of a Cyclohexadienone

chiral biaryl natural products. Tang and co-workers69 reported an asymmetric cross-coupling reaction with an ortho-oxygen functionality in excellent yields and enantioselectivities using a chiral monophosphorus ligand (R)-L49. The presence of a polarπ interaction between the highly polarized BOP group (bis(s-oxo-3oxazolidinyl)phosphinyl) and the extended π system of

achieving excellent enantioselectivities (Scheme 35b). The chiral biaryl products were easily derivatized to form compounds with various functionalities without loss of enantiomeric purities. Although asymmetric Suzuki−Miyaura cross-couplings have shown great efficiency for construction of chiral biaryls, it was only recently that this was applied in efficient total synthesis of 4826


Review

ACS Catalysis

Scheme 33. Desymmetrization by Suzuki−Miyaura CrossCoupling

Scheme 30. Asymmetric Heck Reaction of an (Arene) Chromium Complex

Scheme 31. Intramolecular Asymmetric Heck Reaction of Carbamoyl Chlorides

π system of the other coupling partner. By using chiral monophosphorus ligand (S)-L9, a series of chiral biaryl triflates were formed in moderate to excellent yields and enantioselectivities (Scheme 37). 5.2. Asymmetric C(sp2)−C(sp3) Cross-Coupling. Transition-metal-catalyzed asymmetric cross-couplings with sp3 carbon represents another useful carbon−carbon bond forming transformation in organic synthesis to construct carbon stereocenters. In 2001, Buchwald and co-workers71 reported a Pd-catalyzed asymmetric cross-coupling of α-alkyl-α′-protected cyclopentanones with aryl bromides by using a chiral monophosphorus ligand (S)-L50. The cross-coupling products with quaternary stereocenters were provided in good yields and good to excellent ee’s (Scheme 38a). In 2009, Buchwald and co-workers72 expanded the substrates to oxindoles with a chiral monophosphorus ligand (S)-iPr2MOP (L51) to give product 126a in a promising yield and ee (Scheme 38b). In order to avoid racemization and/or double arylation sideproducts, the enantioselective α-arylations of carbonyl compounds were limited to the formation of quaternary centers.71,73 In 2011, Zhou and co-workers74 achieved the first α-arylation of esters to form chiral tertiary carbon centers in high enantioselectivities by using silyl ketene acetals as substrates and LiOAc as the activator. The (R)-H8−BINOL-derived chiral monophosphorus ligand (R)-L52 was efficient for this reaction. The structure of the silyl ketene acetals exerted a large influence on the efficiency of the coupling and the use of bulky (E)-O-TMS substrates proved to be most effective (Scheme 39). A Ni-catalyzed enantioselective Negishi cross-coupling reaction of 4-methoxypyridinium salts with a chiral monophosphoramidite ligand L53 was reported by Doyle and co-workers.75 After optimization of the nickel precursors, ligands, substrates, and activators, the Ni-catalyzed asymmetric Negishi crosscoupling proceeded successfully to give coupling products 134 with good to excellent yields and enantioselectivities (Scheme 40a). A racemic metal complex C5 with PPh3 as the ligand was isolated, and its structure was confirmed by single X-ray diffraction (Scheme 40b). A Ni(II) allyl intermediate, analogous to a Ni(II) complex formed by oxidative addition of a Ni(0) species into the CN π bond of the pyridinium salt, was proposed as the key intermediate (Scheme 40c).

Scheme 32. Asymmetric Cross-Coupling for the Synthesis of 1,1′-Binaphthyls

the arylboronic acid partner was proposed to play a role for achieving the excellent enantioselectivities. The method was successfully applied in efficient enantioselective synthesis of chiral biaryl natural products korupensamine A, B, and their heterodimer michellamine B (Scheme 36). Efficient asymmetric Suzuki−Miyaura coupling was also achieved on substrates with ortho-triflate functionality.70 The polar triflate group, acting similarly as the aforementioned OBOP group, was believed to provide a noncovalent interaction with the 4827


Review

ACS Catalysis Scheme 34. Asymmetric Suzuki−Miyaura Cross-Coupling with Modified Chiral Monophosphorus Ligands

Scheme 35. Asymmetric Suzuki−Miyaura Cross-Couplings with Various Functional Groups

Doyle and co-workers76 also reported a Ni-catalyzed asymmetric Suzuki−Miyaura cross-coupling of quinolinium ions with a TADDOL-derived chiral monophosphorus ligand L54 to give the arylation products in moderate to good yields and enantioselectivities (Scheme 41). Oxidative addition of Ni(0) into the quinolinium ion (generated from boronate-assisted ionization of the starting material) formed the key intermediate of the catalytic cycle. The nucleophilic α-amino anions were also successfully employed in the Pd-catalyzed cross-coupling to synthesize chiral amines. Buchwald and co-workers77 achieved the Pd-catalyzed asymmetric arylation of α-amino anions with a chiral monophosphorus ligand (R)-L55. The arylation products of 9-aminofluorene-derived imines were easily converted to chiral tertiary amine derivatives (Scheme 42). Chiral monophosphorus ligands can provide better stereoselectivities than chiral diphosphines in some reactions. Morken

and co-workers78 reported a Pd-catalyzed asymmetric coupling between achiral geminal bis(boronates) and aryl halides with a TADDOL-derived chiral monophosphoramidite ligand. The catalytic reaction showed a broad substrate scope to form the corresponding coupling products in moderate to good yields and excellent enantioselectivities (Scheme 43a). Preliminary studies indicated that the transmetalation step was stereospecific. In a related study, Hall and co-workers79 reported the desymmetric coupling with aryl bromides with a similar chiral monophosphoramidite ligand in better yields and enantioselectivities (Scheme 43b). The base NaOH was proposed to activate the di(boronates) by hydrolyzing the boronate prior to the transmetalation step (Scheme 43c). Allylboronic acids can also be employed for asymmetric Suzuki−Miyaura cross-coupling. In 2014, Morken and coworkers80 achieved an intramolecular cross-coupling of aryl chlorides with allyl boronates using a TADDOL-derived chiral 4828


Review

ACS Catalysis

Scheme 36. Asymmetric Suzuki−Miyaura Cross-Coupling with ortho-OBOP Functionality and Applications in Synthesis

Scheme 39. Asymmetric α-Arylation of Esters Reported by Zhou

Scheme 37. Asymmetric Suzuki−Miyaura Cross-Coupling with ortho-Triflate Functionality

6. ASYMMETRIC C−H BOND FUNCTIONALIZATION C−H bond functionalization has received much attention recently because of its atom- and step-economical process. The transition-metal-catalyzed asymmetric C−H bond functionalization remains a very challenging area. Thanks to the development of chiral monophosphorus ligands some interesting transformations have been realized. 6.1. Asymmetric C(sp3)−H Bond Functionalization. The C(sp3)−H bond functionalization is challenging and attractive because of the difficulty in activating the C(sp3)−H inert bonds. Thanks to the development of chiral monophosphorus ligands, progress on transition-metal-catalyzed asymmetric C(sp3)−H bond functionalization has flourished in recent years. In 2012, Cramer and co-workers81 developed a class of novel chiral biaryl monophosphorus ligands by combining the Buchwald-type backbone and the electron-rich phospholane moiety, which were successfully applied in the Pd-catalyzed asymmetric C(sp3)−H bond functionalization of unactivated methyl and methylene bonds. The intramolecular C(sp3)−H arylation with Sagephos ((R,R)-L28) as the ligand led to formation of the corresponding indoline derivatives in moderate to good yields and excellent enantioselectivities (Scheme 45a). The carboxylic acid additive was believed to participate in the transmetalation step in a cooperative manner, which was critically important for the catalyst performance and the enantioselectivity. The employment of the ligand (S,S)-L59 further expanded its substrate scope, allowing aryl bromides instead of aryl triflates as the substrates (Scheme 45b).

Scheme 38. Asymmetric Cross-Coupling of Oxindoles with an Aryl Bromide

monophophoramidite ligand (R,R)-L58 to form the carbocyclic products in moderate ee’s (Scheme 44). 4829


Review

ACS Catalysis Scheme 40. Ni-Catalyzed Enantioselective Negishi Cross-Coupling Reaction Reported by Doyle

Scheme 41. Ni-Catalyzed Asymmetric Suzuki−Miyaura Cross-Coupling of Quinolinium Ions

Scheme 43. Desymmetric Coupling of Geminal Bis(boronates)

Scheme 42. Asymmetric Arylation of 9-AminofluoreneDerived Imines

cyclopropanes are limited. In 2012, Cramer and co-workers82 reported a Pd-catalyzed direct C(sp3)−H arylation of unbranched cyclopropylmethyl anilines using a TADDOL-derived chiral monophosphoramidte ligand (R,R)-L60, providing an efficient method of constructing the tetrahydroquinoline scaffold in excellent enantioselectivities (Scheme 46). The cyclopropyl ring was opened under hydrogenation conditions to provide a chiral seven-membered cyclic structure. Other substituted cyclopropanes with different linkers were also transformed under similar reaction conditions to give enantiomerically enriched C(sp3)−H arylation products83 (Scheme 47). The readily available α-haloacetamides were also employed for the Pd-catalyzed intramolecular asymmetric C(sp3)−H functionalization, giving a series of chiral β-lactams84 in excellent ee’s

Although cyclopropanes have become increasingly useful in many fields, efficient methods for the synthesis of chiral-substituted 4830


Review

ACS Catalysis

Scheme 47. Pd-Catalyzed Direct C(sp3)−H Arylation of Substituted Cyclopropanes

Scheme 44. Intramolecular Coupling of Arylchlorides with Allyl Boronates

chloroacetamides to form chiral γ-lactams with azabicyclo[3.1.0]hexane scaffolds in good to excellent yields and enantioselectivities (Scheme 49). In addition, the cyclopropyl ring of the product was opened under hydrogenation conditions to form stereospecifically a chiral β,γ-disubstituted-γ-lactam. 6.2. Asymmetric C(sp2)−H Bond Functionalization. The direct functionalization of C(sp2)−H bonds is a highly active research field because of its high efficiency in accessing various biological active products from readily available starting materials. Recent development of chiral monophosphorus ligands enabled the fast growth of its asymmetric version. In 2009, Cramer and co-workers86 reported a room-temperature intramolecular direct arylation of vinyl triflates 166 to form bicyclic compounds 167 in excellent enantioselectivities using a TADDOL-derived chiral monophosphoramidite ligand (R,R)-L63 (Scheme 50). Further studies disclosed a Pd-catalyzed intramolecular asymmetric arylation of aryl bromide 168 via a rare eight-membered palladacycle intermediate. The TADDOL-derived chiral monophosphoramidite ligand (R,R)-L42 was applied to provide dibenzazepinones possessing a quaternary stereocenter in excellent enantioselectivities. Heteroarene substrates were also suitable. An exclusive C(sp2)−H activation over the competing C(sp3)−H one was observed, which would otherwise provide five- or six-membered cyclic products (Scheme 51a).87 Under similar conditions, an array of quinolin-2(1H)-ones equipped with planar chiral ferrocene moieties were formed in good yields and excellent enantioselectivities by using a chiral monophosphoramidite (R,R)-L64 as the ligand (Scheme 51b).88 Asymmetric C(sp2)−H functionalization was employed to synthesize biaryl compounds with P-stereogenic centers, which were of great interest in the fields of agrochemicals, materials, and chiral ligands design. Duan89 and Liu90 independently reported the Pd-catalyzed intramolecular C−H arylation with TADDOL-derived chiral monophosphoramidite ligands to form the P-stereogenic phosphinic amides in good yields and excellent enantioselectivities (Scheme 52). Tang and co-workers91 reported the Pd-catalyzed intramolecular C−H arylation to form P-chiral biaryl phosphonates with a bulky chiral biaryl monophosphorus ligand L8 in moderate to good yields and enantioselectivities (Scheme 53). Notably, the aryloxy substituents of the phosphonate products could be displaced stereospecifically by various alkyl lithium or Grignard reagents sequentially. Transition-metal-catalyzed asymmetric allylic substitution generally employs substrates with a leaving group at the allylic position. Catalytic direct allylic substitution of allylic C−H bonds is one of more attracting methods in terms of atom- and step-economy. In 2013, Trost and co-workers92 developed a novel chiral monophosphoramidite ligand L65 and applied it in the Pd-catalyzed asymmetric alkylation of allylic C−H bonds.

Scheme 45. Asymmetric C(sp3)−H Bond Functionalization of Inactive Methyl and Methylene C−H Bonds

Scheme 46. Pd-Catalyzed Direct C(sp3)−H Arylation of Unbranched Cyclopropylmethyl Anilines

(Scheme 48a). A TADDOL-derived chiral monophosphoramidite ligand (R,R)-L61 was employed to provide a best catalytic activity and enantioselectivity, and adamantyl carboxylic acid was used as a cocatalyst engaging in the enantiomerically determining concerted metalation−deprotonation (CMD) step. Under optimized conditions, the undesired SN2 pathway was effectively inhibited, which would otherwise lead to the ester side-product as well as the racemic background reaction (Scheme 48b). With a bulky TADDOL-derived chiral monophosphonite ligand (R,R)-L62, Cramer and co-workers85 disclosed a Pd-catalyzed enantioselective C(sp3)−H functionalization of readily accessible 4831


Review

ACS Catalysis Scheme 48. Pd-Catalyzed Asymmetric Synthesis of Chiral β-Lactams

Scheme 49. Pd-Catalyzed Asymmetric Synthesis of Chiral γLactams

Scheme 51. Pd-Catalyzed Intramolecular Cyclization via Asymmetric C(sp2)−H Arylation

Scheme 50. Pd-Catalyzed Asymmetric Direct Arylation of Vinyl Triflates

Scheme 52. Pd-Catalyzed Intramolecular C−H Arylation To Form the P-Stereogenic Compounds

Reaction of allylarene with 1,3-diketones 174 as pronucleophiles provided the corresponding coupling products bearing a chiral quaternary carbon center in good yields and excellent enantioselectivities (Scheme 54a). In 2015, Gong and co-workers42b expanded this catalytic reaction to the intramolecular aryloxylation of allylic C−H bonds under similar conditions. A series of enantiomerically enriched chromans were efficiently synthesized, and studies indicated that the allylic C−H cleavage was the ratelimiting step (Scheme 54b). from simple starting materials. Chiral monophosphorus ligands are playing increasingly important roles for the recent progress in the field. 7.1. Nickel-Catalyzed Asymmetric Coupling of π-Systems. Nickel(0) species coordinated with a monophosphorus ligand are capable of activating π bonds and forming cyclometalated nickel complexes, which can interact with another σ/π bond to form multiple bonds in a single reaction.

7. ASYMMETRIC COUPLING OF π-SYSTEMS The metal-catalyzed coupling of two or more π systems (alkenes, alkynes, allenes, aldehydes, aldimines, ketones, dienes, etc.) often forms multiple bonds in one pot with great atom economy and efficiency and thus has attracted much attention. The metalcatalyzed asymmetric coupling of two π systems was most studied, providing chiral molecules with considerable complexity 4832


Review

ACS Catalysis

Ni-catalyzed alkylative coupling of unsymmetrical aryl-substituted alkynes, aromatic aldehydes, and ZnMe2, providing an efficient approach to a variety of chiral allylic alcohols with tetrasubstituted olefin moiety in high yields, enantioselectivities, and regioselectivities (Scheme 56a). An efficient chiral nickel catalyst for both aromatic and aliphatic aldehydes was recently disclosed by Tang and co-workers97 using a P-chiral monophosphorus ligand BI-DIME. With ZnMe2 as the alkylative reagent, the Ni-catalyzed alkylative coupling of unsymmetrical aryl-substituted alkynes and aliphatic/aromatic aldehydes was developed to provide a series of chiral tetrasubstituted olefinic allylic alcohols in high yields and good to excellent enantioselectivities (Scheme 56b). A heterobimetallic compound silylborane was also employed for the diene/aldehyde coupling. Saito and co-workers98 reported a three-component Ni-catalyzed coupling of 1,3-dienes, aldehydes, and PhMe2SiB(pin) to give chiral allylsilane derivatives in moderate to good yields and excellent enantioselectivities, with the employment of a bulky chiral monophosphoramidite ligand (Ra)-L69 (Scheme 57). The Ni-catalyzed asymmetric reductive/alkylative coupling of alkynes and aldimines was also successfully developed. Jamison and co-workers99 reported the alkylative coupling reaction of alkynes and aldimines with Et3B as the alkylative reagent using a P-chiral ferrocenyl monophosphorus ligand L3 to form the corresponding coupling products in moderate to good yields with good enantio- and regioselectivities (Scheme 58a). The TBSOCH2CH2−protected allylic amines were deprotected easily to form primary allylic amines. Zhou and co-workers99 developed a Ni-catalyzed reductive coupling of alkynes and aldimines with Et2Zn as the reductant using a chiral spiro monophosphorus ligand L70 (Scheme 58b). Both catalytic reactions

Scheme 53. Pd-Catalyzed Intramolecular C−H Arylation To Form the P-Stereogenic Phosphonates

The Ni-catalyzed coupling of π systems was reviewed.93 However, limited progress was achieved on highly enantioselective Ni-catalyzed coupling. The Ni-catalyzed asymmetric reductive/alkylative coupling reaction of alkynes and aldehydes was well-studied. Different chiral monophosphorus ligands were employed to control the regio- and enantioselectivities. In 2003, Jamison and co-workers94 reported the first highly regio- and enantioselective nickelcatalyzed reductive coupling of unsymmetrical aryl-substituted alkynes and aliphatic aldehydes with a chiral monophosphorus ligand (+)-NMDPP to form a series of allylic alcohols in good to excellent yields and enantioselectivities (Scheme 55a). The Ni-catalyzed reductive coupling of 1,3-enynes 183 and aromatic aldehydes with a P-chiral ferrocenyl monophosphorus ligand (R)-L3 was also reported to provide the conjugated dienols in high regioselectivities and modest enantioselectivities (Scheme 55b).95 By employing a chiral spiro monophosphoramidite ligand (Ra)L68, Zhou and co-workers96 realized a highly enantioselective

Scheme 54. Pd-Catalyzed Asymmetric Functionalization of Allylic C−H Bonds

Scheme 55. Ni-Catalyzed Asymmetric Reductive Coupling of Alkynes and Aldehydes

4833


Review

ACS Catalysis Scheme 56. Ni-Catalyzed Asymmetric Alkylative Coupling of Alkynes and Aldehydes

(Scheme 59b). Mechanistic studies suggested that the active catalyst was formed in situ with a Ni/ligand ratio of 1/1. 7.2. Gold-Catalyzed Asymmetric Coupling of π-Systems. Gold catalysts have played a unique role in homogeneous catalysis due to their high activity in activating π systems. However, the main drawback of a dicoordinated Au(I) complex is its linear geometry, which sets the active reaction site at the opposite side of the chiral ligand. The ligand is thus required to possess an extended chiral pocket in order to achieve an excellent enantioselectivity. Several highly enantioselective Au-catalyzed coupling of π bonds were developed thanks to the development of several efficient chiral monophosphorus ligands.102 In 2009, Mascareñas and co-workers103 developed the Aucatalyzed [4 + 2] cycloadditions of allenedienes. By using a chiral monophosphoramidite-based gold catalyst L71-AuCl, the 6,6trans-fused bicyclic product 204a was prepared in a good yield and excellent enantioselectivity (Scheme 60a). Experimental results as well as DFT calculations suggested that a [4 + 3] cycloaddition pathway was preferred followed by a ring contraction (Scheme 60b). Toste and co-workers104 also reported a similar cycloaddition using another chiral monophosphoramidite ligand L72, and good to excellent enantioselecitities were achieved. By using a bulky chiral monophosphite ligand L73, an Au-catalyzed [4 + 2] cycloaddition of multisubstituted allenedienes was developed to provide cycloaddition products in good to excellent yields and enantioselectivities (Scheme 60c). Using a bulky chiral monophosphoramidite ligand L74, Toste and co-workers105 reported the Au-catalyzed asymmetric cycloaddition/alkoxylation of allenes in moderate to good yields and excellent enantioselectivities (Scheme 61a). Aliphatic alcohols and water were used as nucleophiles. By employing

Scheme 57. Ni-Catalyzed Three-Component Coupling with a Silylborane as the Reagent

were not efficient for imines derived from aliphatic aldehydes (in moderate yields and enantioselectivities). Due to the lower activity of the ketones, the asymmetric coupling of alkynes and ketones was rarely reported. Jamison and co-workers100 reported an intermolecular Ni-catalyzed reductive coupling of 1,3-enynes and aromatic ketones with Et3B as the reductant using L3 as the ligand, providing the conjugated dienols in moderate to good yields with moderate enantioselectivities (Scheme 59a). The regioselectivity of the reaction was well-controlled, dictated by the coordination of the olefin moiety of the 1,3-enynes to the nickel catalyst. A highly enantioselective Ni-catalyzed intramolecular reductive coupling of alkynones was first developed by Tang and co-workers.101 When a bulky chiral biaryl monophosphorus ligand AntPhos/BI-DIME was employed, a variety of tertiary allylic alcohols bearing tetrahydrofuran/pyran rings were prepared in excellent yields and enantioselectivities

Scheme 58. Ni-Catalyzed Reductive/Alkylative Coupling of Alkynes and Aldimines

4834


Review

ACS Catalysis

(Scheme 62a). The introduction of a methyl substituent at the internal position of allenes afforded the bicyclic products with a quaternary carbon stereocenter (Scheme 62b). Chiral cyclic/acyclic TADDOL-derived monophosphoramidites were also efficient ligands for the Au-catalyzed asymmetric cyclizations. Fürstner and co-workers107 found that the [2 + 2] cycloaddition of alkenes and allenes catalyzed by a Au-monophosphoramidite complex proceeded in good to excellent yields and enantioselectivities. The bulky chiral acyclic TADDOLderived monophophoramidite L75 was even more effective (Scheme 63). The X-ray structures of the Au-monophosphoramidites complexes revealed that the three phenyl groups of the ligands were all important for the stereocontrol. The chiral TADDOL-derived monophosphoramidite ligands were also effective in the [4 + 2] cycloaddition, cycloisomerization of enynes, hydroarylation of allenes, and hydroamination/hydroalkoxylation of allenes.108 An Au-catalyzed asymmetric intermolecular [2 + 2] cycloaddition of sulfonylallenamines and vinylarenes was realized with a chiral monophosphoramidite ligand L76.109 The cyclobutane derivatives were prepared in moderate to good yields and up to 92% ee (Scheme 64). An interesting ligand with a helicene skeleton was designed for the asymmetric Au-catalyzed cycloaddition. Marinetti and co-workers110 developed the chiral monophosphorus ligand HelPHOS (L11), which was applied in the Au-catalyzed cycloisomerization of enynes with good enantioselectivities and acceptable yields (Scheme 65). Zhang and co-workers111 reported an Au-catalyzed asymmetric alkyne oxidation/cyclopropanation to form a series of bicyclo[3.1.0]hexan-2-ones containing three contiguous stereocenters in good to excellent yields with excellent enantioselectivities. A bulky chiral BINOL-derived monophosphoramidite

Scheme 59. Ni-Catalyzed Reductive Coupling of Alkynes and Ketones

the chiral spiro monophosphoramidite ligand L41, the intramolecular [2 + 2] cycloaddition of allenes and alkenes was also achieved, albeit with a limited substrate scope (Scheme 61b). Using the same chiral monophosphoramidite-based gold catalyst L71-AuCl, Mascareñas and co-workers106 achieved the intramolecular [4 + 3] cycloaddition of allenedienes by changing the terminal substituents of allenes from dialkyl groups to monosubstituted and hydrogen groups. The corresponding bicycles were prepared in good to excellent yields and enantioselectivities

Scheme 60. Au-Catalyzed Asymmetric [4 + 2] Cycloaddition of Allenedienes

4835


Review

ACS Catalysis Scheme 61. Au-Catalyzed Asymmetric Cycloaddition/Alkoxylation of Allenes

the most studied. The rhodium-catalyzed asymmetric Pauson− Khand reaction of 1,6-enynes using a chiral monophosphoramidite ligand SIPHOS instead of bidentate ligands was reported by Zhou and co-workers.113 The corresponding products were formed in moderate yields with good enantioselectivities (Scheme 68). Enantioselective rhodium-catalyzed [2 + 2+2]/[4 + 2+2] cycloadditions of isocyanates/carbodiimides bearing terminal alkenes/1,3-dienes with aromatic terminal alkynes,114 aliphatic terminal alkynes,114c,115 or internal alkynes116 (Figure 1) were first developed by Rovis and co-worker with chiral TADDOL/ biphenol-derived monophosphoramidite ligands, which was well-reviewed117 in 2009. Mechanistic studies118 indicated that the elimination/reinsertion of CO was involved in the cycloaddition. In 2011, Rovis and co-workers119 reported the Rh-catalyzed [4 + 2] cycloaddition of α,β-unsaturated imines and isocyanates. By using a monophosphoramidite L78 as the ligand, a series of pyrimidinones were obtained in good yields and excellent enantioselectivities (Scheme 69). In order to control the elimination/reinsertion of CO in the catalytic cycloaddition, a chiral TADDOL-derived monophosphoramidite ligand CKphos L83 was developed. X-ray diffraction, NMR analysis, and DFT caculations120 revealed a shortened Rh−P bond and coordination of one C6F5 to the rhodium center via a weak Lewis acidic, Z-type interaction. Excellent chemoselectivities and enantioselectivities121 were achieved with CKphos as the ligand (Scheme 70). The Rh/monophosphoramidite complex was also used as a Lewis acid to catalyze an intramolecular cyclization of 4-iminocrotonates. A bulky chiral monophosphoramidite ligand TIPS-Guiphos L84 was developed and applied to the enantioselective cyclization, providing a convenient access to 5-alkyoxy3-pyrrolin-2-ones (240) in good yields and excellent enantioselectivities. A possible catalytic cycle was proposed122 (Scheme 71). Silicon-stereogenic dibenzosiloles and germanium-stereogenic dibenzogermoles were prepared by Rh-catalyzed asymmetric

Scheme 62. Au-Catalyzed Asymmetric [4 + 3] Cycloaddition of Allenedienes

ligand L77 was used. Preliminary mechanistic studies suggested that a β-gold vinyloxyquinolinium intermidediate was involved (Scheme 66). An Au-catalyzed asymmetric intermolecular [3 + 2] annulation of 2-(1-alkynyl)-2-alken-1-ones (225) and N-allenamides 226 was reported by Zhang and co-workers.112 The bulky chiral BINOL-derived monophosphoramidite ligand L71 was employed to form 3,4-ring-fused furans in good yields and excellent enantioselectivities (Scheme 67). 7.3. Rhodium-Catalyzed Asymmetric Coupling of π-Systems. Cycloadditions with rhodium catalysts are among Scheme 63. Au-Catalyzed Asymmetric [2 + 2] Cycloaddition

4836


Review

ACS Catalysis Scheme 64. Au-Catalyzed Asymmetric Intermolecular [2 + 2] Cycloaddition

Scheme 65. Au-Catalyzed Cycloisomerization of Enynes with HelPHOS

Scheme 67. Au-Catalyzed Asymmetric Intermolecular [3 + 2] Annulation

[2 + 2+2] cycloaddition of triynes with internal alkynes. High yields and enantioselectivities were achieved by employing an axially chiral monophosphorus ligand L85123 (Scheme 72a). When isocyanates instead of internal alkynes were employed as substrates, silicon-stereogenic silicon-bridged arylpyridinones were obtained in good yields and enantioselectivities124 (Scheme 72b). On the basis of the results from controlled experiments and kinetic studies, a catalytic cycle was proposed. Cyclometalation of alkyne on the benzene ring of 241a and CN of 244 with cationic Rh(I) species gave a five-membered rhodacyle containing a Rh− N bond to establish the regiochemistry in the product formation. A subsequent enantioselective intramolecular insertion of one of the alkynes on silicon into the Rh−C bond gave a sevenmembered rhodacycle. Reductive elimination provided the product and regenerated the Rh(I) species (Scheme 72c).

Scheme 68. Rh-Catalyzed Asymmetric Pauson−Khand Reaction of 1,6-Enynes

8. ASYMMETRIC ADDITION 8.1. Asymmetric Conjugate Addition. Transition-metalcatalyzed conjugate addition of a carbon-nucleophile to an activated double bond remains one of most important carbon−carbon Scheme 66. Au-Catalyzed Asymmetric Alkyne Oxidation/Cyclopropanation

4837


Review

ACS Catalysis

Figure 1. Chiral monophosphoramidite ligands used in Rh-catalyzed cycloadditions.

Scheme 69. Rh-Catalyzed Asymmetric [4 + 2] Cycloaddition

Scheme 71. Rh-Catalyzed Asymmetric Cyclization of 4-Iminocrotonates

Scheme 70. Rh-Catalyzed Cycloadditions with CKphos as the Ligand

in 2010 by Alexakis (Scheme 73). This section will focus on the recent development in the field. Alexakis and co-workers128 developed an olefinic aluminum reagent MeAl(CHCHR), which were easily prepared from readily available terminal alkynes. The nucleophilic reagents were successfully employed in the Cu-catalyzed asymmetric addition to cyclohexenones with moderate to good yields and up to 98% ee (Scheme 74). Conjugate imines are excellent Michael acceptors with dialkylzinc as the nucleophilic reagents. The corresponding products are easily transformed into ketones, enamines, and amines, which are ubiquitously present in natural products and functional molecules. In 2005, Carretero and co-workers129 reported an 1,4addition of Me2Zn to N-sulfonyl imines derived from chalcones. Up to 80% ee was achieved by using a Cu/BINOL-monophosphoramidite catalyst in the case of N-2-pyridylsulfonyl imines (Scheme 75a). Palacios and co-workers130 expanded the asymmetric conjugate addition of acyclic N-aryl α-iminoesters with Et2Zn as the nucleophile using a Cu/TADDOL-based monophosphoramidite catalyst, and up to 88% ee was achieved (Scheme 75b). Zezschwitz and co-workers131 developed a Cu-catalyzed asymmetric conjugate addition of Et2Zn to the cyclic/acyclic N-tosyl imines using a monophosphoramidite ligand L14 with up to 96% ee (Scheme 75c). The use of alkylzirconium reagents in the Cu-catalyzed asymmetric addition allowed the conjugate addition to introduce a variety of alkyl nucleophiles. With a chiral BINOL-derived monophosphoramidite ligand, Fletcher and co-workers developed the Cu-catalyzed asymmetric conjugate addition of alkylzirconium reagents to α,β-unsaturated lactones,132 acyclic keotnes,133 and cyclic ketones134 in moderate to good yields and good to excellent

bond-forming methods. Chiral bidentate ligands have played a major role in the development of its asymmetric version. In the past decade, more and more chiral monophosphorus ligands were employed for the asymmetric conjugate addition. Among these chiral monophosphorus ligands, the chiral monophosphoramidites ligands are most effective. The pioneering work from the Feringa group described the Cu-catalyzed asymmetric conjugate addition of organozinc to cyclic or acyclic disubstituted enones by using BINOL-derived chiral monophosphoramidites ligands with high enantioselectivities and was reviewed in 2000.4b The Fillion group125 developed a Cu-catalyzed asymmetric addition of organozinc reagents to the acyclic tetrasubstituted vinyl carboxylates with chiral monophosphoramidites ligands to form products with quaternary stereocenters. The Alexakis group126 reported the conjugated addition of organoaluminum reagents to the trisubstituted enones using a class of monophosphoramidites ligands SimplePhos to form addition products with tertiary stereocenters. The above progresses were well-reviewed127 4838


Review

ACS Catalysis Scheme 72. Rh-Catalyzed Asymmetric [2 + 2+2] Cycloaddition of Triynes

Scheme 73. Cu-Catalyzed Asymmetric Conjugate Addition to Enones

For the unsymmetrical dialkylidene ketones,136 the nickel/L62 catalyst provided better performance. Good yields and high regio- and enantioselectivities were achieved. However, the substrates were limited to the aryl-substituted dialkylidene ketones (Scheme 76b). For less sterically hindered methylidene ketones substrates, a chiral monophosphoramidite ligand L89137 was suitable for both aryl- and alkyl-substituted methylidene ketones, and the corresponding products were obtained in excellent regioselectivities and enantioselectivities (Scheme 76c). Mechanistic studies suggested that the reaction proceeded via a Lewis acid-induced oxidative addition of the metal to the less-hindered alkylidene enone, followed by a transmetalation and a 3,3′reductive elimination process136 (Scheme 76d). In 2011, Hu and co-workers138 developed a sequential aldol condensation of aldehydes with methyl ketones followed by a Rh-catalyzed conjugate addition of arylboronic acids. Its asymmetric version was realized by using a chiral spiro monophosphorus ligand L90 to provide the desired products in good yields and excellent enantioselectivities (Scheme 77). This protocol simplified the syntheses of α,β-unsaturated ketones and also expanded the utilities of asymmetric addition. By combining cost-effective copper catalysts and air-stable organoboron reagents, Zhou and co-workers139 realized the asymmetric conjugate addition of organoboron reagents to acyclic enones. With the arylboroxines as the nucleophile and a

Scheme 74. Cu-Catalyzed Asymmetric Addition with ClMeAl(CHCHR) Reagents

enantioselectivities (Figure 2). The alkylzirconium reagents were generated in situ from alkenes and the Schwartz reagent Cp2ZrHCl. Organoboron reagents are a class of air-stable, nontoxic, and operationally friendly reagents with increasing applications in organic chemistry. In 2006, Morken and co-workers135 reported the Pd-catalyzed asymmetric conjugate addition of allylboronic acid to a symmetrical dialkylidene ketone with a TADDOLderived monophosphoramidite ligand L58 (Scheme 76a). 4839


Review

ACS Catalysis Scheme 75. Cu-Catalyzed Asymmetric Conjugate Addition of Dialkylzinc to Conjugate Imines

Scheme 77. Sequential Aldol Condensation of Aldehydes with Methyl Ketones Followed by Rh-Catalyzed Conjugate Addition of Arylboronic Acids

Design of new chiral ligands continues to be of importance in developing new efficient catalytic reactions and expanding the substrate scope. Iuliano and co-workers140 introduced a biphenol-based monophosphite ligand (Sa)--L45 with an deoxycholic acid backbone, and high enantioselectivities were achieved when it was applied in the Rh-catalyzed asymmetric conjugate additions of arylboronic acids to cyclic enones140a and nitroalkenes140c (Scheme 79a). Kim and co-workers141 reported the development of a novel chiral monophosphoramidite ligand (R)-L25, which was used as an effective ligand in the Rhcatalyzed asymmetric conjugate addition of arylboronic acids to α,β-unsaturated imino esters (Scheme 79b).

Figure 2. Cu-catalyzed asymmetric conjugate addition of alkylzirconium reagents.

chiral spiro monophosphoramidite L91 as the ligand, the reaction proceeded smoothly to afford the addition products in good yields and excellent enantioselectivities (Scheme 78a). DFT calculations as well as experimental results suggested that a rare 1,4-insertion pathway was involved and a six-membered transition state led to the formation of an O-bound copper enolate (Scheme 78b).

Scheme 76. Asymmetric Addition of AllylBpin to Dialkylidene Ketones

4840


Review

ACS Catalysis Scheme 78. Cu-Catalyzed Asymmetric Conjugate Addition of Arylboroxines to Acyclic Enones

Scheme 80. Rh-Catalyzed Asymmetric Arylation of Imines

transition metals such as Rh,149 Ni,150 Ru,151 and Cu152 were studied for the transformation. In 2006, Zhou and co-workers149a reported the Rh-catalyzed asymmetric addition of arylboronic acids to aldehydes using a chiral spiro monophosphite ligand L96, affording diarylmethanols in excellent yields and good enantioselectivities (Scheme 82a). Hu and co-workers149b developed a Rh-catalyzed arylation of aldehydes followed by an in situ lactone formation process to give 3-substituted phthalides in good yields and high enantioselectivities (Scheme 82b). In 2009, Morken and co-workers150 reported the Ni-catalyzed asymmetric addition of allylic boronate to dienals with a chiral TADDOL-derived monophosphite ligand L62. The 1,2-addition of aldehydes was supposed to undergo an unsaturated π-allyl intermediate followed by 3,3′-reductive elimination with a remarkable inversion of an olefin geometry (Scheme 83). Tang and co-workers151 developed a Ru-catalyzed asymmetric addition of arylboronic acids to aldehydes with a bulky chiral biaryl monophosphorus ligand L4. A series of diarylmethanols were formed in excellent yields and enantioselectivities. An active Ru complex C6 was isolated and the structure was confirmed by X-ray crystallography. One phenoxy group of the ligand served as a coordinating aryl group within the complex (Scheme 84). In 2015, Meek and co-workers152 achieved a Cu-catalyzed addition of alkylboronates to aldehydes with MonoPhos (Ra)L15 as the chiral ligand, providing the 1,2-diols after oxidation of boronates in moderate to good yields and excellent enantioselectivities with up to >99/1 diastereoselectivities (Scheme 85). The transition-metal-catalyzed asymmetric addition of carbon, nitrogen, oxygen-nucleophiles to inter- or intramolecular alkenes

8.2. Asymmetric 1,2-Addition. The transition-metalcatalyzed asymmetric addition of organometallic reagents to imines, ketones, aldehydes, and alkenes represents an attractive research field in organic synthesis.142 Early progress in this field mainly employed chiral bidentate ligands. Hayashi’s pioneering work143 demonstrated chiral monophosphorus ligands could also lead to high activity as well as good enantioselectivity. Today, significant progress has been achieved with the use of various chiral monophosphorus ligands. The Rh-catalyzed asymmetric arylation of arylimines with organometallic reagents attracted much attention. In 2000, Hayashi and co-workers143 developed a highly enantioselective arylation of imines with organostannane reagents using a chiral monophosphorus ligand L92. Using a chiral BINOL-derived monophosphoramidite ligand L93, Feringa and co-workers144 reported a Rh-catalyzed arylation of imines with arylboronic acids, and up to 95% ee was achieved. Comparably good results were also achieved by Zhou and co-workers145 with a chiral spiro monophosphite ligand (Sa)-ShiP L23 (Scheme 80). Besides arylation of imines, the Rh-catalyzed asymmetric addition of arylboronic acids to activated ketones was efficiently realized by the Hayashi,146 Feringa,147 and Zhou148 groups with various chiral monophosphorus ligands (Scheme 81). Aldehydes are more difficult substrates than imines and activated ketones for achieving high enantioselectivities. Various

Scheme 79. Rh-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids

4841


Review

ACS Catalysis Scheme 81. Rh-Catalyzed Asymmetric Arylation of Activated Ketones

Scheme 82. Rh-Catalyzed Asymmetric Addition of Arylboronic Acids to Aldehydes

Scheme 84. Ru-Catalyzed Asymmetric Addition of Arylboronic Acids to Aldehydes

Scheme 85. Cu-Catalyzed Asymmetric Addition of Alkylboronates to Aldehydes

Scheme 83. Ni-Catalyzed Asymmetric Addition of Allyl Boronates to Dienals

Scheme 86. Ni-Catalyzed Asymmetric Addition of Terminal Alkynes to 1,3-Dienes

was one of the most important methods to construct structures with carbon stereocenters. In 2010, Suginome and co-workers153 reported a Ni-catalyzed asymmetric addition of terminal alkynes containing an α-siloxy-sec-alkyl group to 1,3-dienes with a chiral TADDOL-derived monophosphoramidite ligand L97, providing hydroalkynylation products in good enantioselectivities (up to 93% ee) (Scheme 86). The use of cis dienes was crucial for achieving high enantioselectivities and activities. In 2013, Tang and co-workers154 reported an Ir-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with amines by using a chiral bulkyl biaryl monophosphorus ligand

L98, providing a series of chiral substituted dihydronaphthalenes in high yields and excellent enantioselectivities (up to 99% ee). 4842


Review

ACS Catalysis Luo and co-workers155 further expanded the asymmetric ringopening reaction with a Rh−BI-DIME catalyst, and products were obtained in excellent enantioselectivities (Scheme 87). The intramolecular addition of heteronucleophiles to alkenes was an efficient way to construct heterocycles. However, asymmetric versions of these reactions with chiral monophosphorus

ligands were limited. In 2010, Buchwald and co-workers156 reported a Rh-catalyzed asymmetric intramolecular hydroamination of alkenes with chiral ligand L99 and the cyclic amines were obtained in good enantioselectivities (up to 91% ee) (Scheme 88a). In 2012, Wolfe and co-workers157 achieved a Pd-catalyzed carboamination of alkenes with a chiral spiro monophosphoramidite Siphos-PE (L100). Mono- or disubstituted terminal alkenes were applicable for the reaction, providing cyclic products with good enantioselectivities (up to 95% ee) (Scheme 88b). An asymmetric Pd-catalyzed carboalkyloxylation158 of alkenes was realized with a chiral TADDOL-derived monophosphite ligand L101. The gem disubstituted groups of alcohols at C-1 position were required for high enantioselectivities (Scheme 88c). With a bulky chiral biaryl monophosphorus ligand L102, a Pd-catalyzed enantioselective alkene aryloxyarylation was developed by Tang and co-workers.159 A series of 1,4-benzodioxanes, 1,4-benzooxazines, and chromans containing quaternary stereocenters were prepared in high enantioselectivities and good yields (Scheme 88d). 8.3. Asymmetric Diboration. By using chiral monophosphorus ligands, transition-metal-catalyzed enantioselective diboration of allenes,160 1,3-dienes,161 and simple alkenes162 offer access to various chiral boronates that can be readily transformed

Scheme 87. Asymmetric Ring Opening of Oxabenzonorbornadienes with Amines

Scheme 88. Intramolecular Asymmetric Addition of Heteronucleophiles to Alkenes

Scheme 89. Pd-Catalyzed Asymmetric Diboration of Allenes

4843


Review

ACS Catalysis Scheme 90. Pt-Catalyzed Asymmetric Diboration of 1,3-Dienes

Scheme 91. Pt-Catalyzed Asymmetric Diboration of Simple Terminal Alkenes

Scheme 92. Pt-Catalyzed Asymmetric Diboration of Vinyl Boronates

Scheme 93. Pd-Catalyzed Asymmetric Silaboration of Terminal Allenes

Scheme 94. Rh-Catalyzed Asymmetric Hydroboration of Arylenamides

to other functional groups. In 2004, Morken and co-workers160a reported a Pd-catalyzed asymmetric diboration of monosubstituted allenes with a chiral TADDOL-derived monophosphoramidite ligand L42 in good yields and high enantioselectivities. The in situ generated chiral allyl vinyl boronates were stereospecifically transformed into various chiral products through allylation,160a,b hydroboration/cross-coupling,160c and α-aminoallylation160d (Scheme 89). By employing different chiral monophosphorus ligands, Morken and co-workers161 expanded the substrate scope of diboration to 1,3-dienes. Both acyclic161a,b and cyclic161c 1,3dienes could be transformed with chiral monophosphorus ligands L103, L104, L10 in high enantioselectivities (Scheme 90). The chiral cis-iBu-OxaPhos showed a remarkable effect of 4844


Review

ACS Catalysis

Scheme 95. Rh-Catalyzed Asymmetric Hydrogenation of Enamides/Enamines with Various Chiral Monophosphorus Ligands

chemo- and regio-selective. For conjugate 1,3-trans-dienes and trisubstituted alkenes, the terminal alkene was selectively transformed. The synthetic utilities of chiral boronates were demonstrated by various transformations such as oxidation,162a allylation addition to aldehydes,162b and cross-coupling with

ligand-accelerated catalysis and a Pt loading as low as 0.02 mol % was operational. With a Pt/monophosphorus ligand catalyst, an asymmetric diboration of simple terminal alkenes was developed by Morken and co-workers.162a−d,f The transformation was highly 4845


Review

ACS Catalysis

Scheme 96. Rh-Catalyzed Asymmetric Hydrogenation of Enamides by Combining Two Different Monophosphorus Ligands

Scheme 97. Self-Supported Heterogeneous Catalysts for Asymmetric Hydrogenation

Scheme 98. Switchable Catalyst for Rh-Catalyzed Hydrogenation

4846


Review

ACS Catalysis aryl/vinyl halides.162d,f Mechanistic studies162c suggested that this reaction occurred by a stereochemistry-determining olefin insertion into the Pt−B bond, furnishing an internal C−Pt bond (Scheme 91).

In 2014, Morken and co-workers162e expanded the diboration of simple terminal alkenes to vinyl boronates using a chiral monophosphorus ligand L106. A series of 1,1,2-triboronates were obtained in good yields and enantioselectivities. The deborylative alkylation of 1,1,2-triboronates underwent easily under basic conditions through an anionic intermediate without loss of enantiomeric excess (Scheme 92). Other than diboration, metal-catalyzed asymmetric silaboration and hydroboration of alkenes with chiral monophosphorus ligands were also developed. In 2006, Suginome and coworkers163 reported a Pd-catalyzed asymmetric silaboration of monosubstituted terminal allenes using a chiral monophosphorus ligand L107. This asymmetric reaction was highly chemoselective, providing β-borylallylsilanes in high enantioselectivities (Scheme 93). In 2015, Tang and co-workers164 developed a Rh-catalyzed asymmetric hydroboration of α-arylenamides with a bulky chiral

Scheme 99. Ir-Catalyzed Asymmetric Hydrogenation of Enamides

Scheme 100. Asymmetric Hydrogenation of Alkenes, Ketones, and Imines

4847


Review

ACS Catalysis

catalyst (Scheme 97a). In 2010, Ding and co-workers168c developed a heteroditopic ligand that contained a 2,2′:6′,2″terpyridine unit and Feringa’s MonoPhos at its ends, which selectively coordinated with Fe(II) and Rh(I) ions for the programmed assembly of a class of chiral bimetallic self-supported catalysts. This heterogeneous catalyst C10 was found to be highly efficient, enantioselective, and reusable in the asymmetric hydrogenation of enamides (Scheme 97b). In 2015, Fan and co-workers169 developed a chiral monophosphoramidite ligand modified by an aza-crown ether. The catalytic activity of its rhodium complex could be switched between the ON and OFF state through Na+-triggered modulation using host−guest interactions. In the ON state, 100% conversion and excellent enantioselectivities were obtained in the asymmetric hydrogenation of enamides (Scheme 98). In 2007, de Vries and co-workers170 reported the Ir-catalyzed enantioselective hydrogenation of enamides with a single bulky chiral monophosphoramidite ligand L127 coordinated to the metal. It was believed that the bulky monophosphoramidite ligand prevented the dimerization of the catalyst, therefore showing high activities (Scheme 99). 9.2. Asymmetric Hydrogenation of Conjugate Alkenes, Aromatic Ketones, and Imines. Chiral monophosphorus ligands were employed in the Rh-catalyzed asymmetric hydrogenation of conjugate alkenes,166a−c,171 Ru-catalyzed asymmetric hydrogenation of aromatic ketones,172 and Ir-catalyzed asymmetric hydrogenation of imines173 with high activities and good enantioselective control, which were summarized in Scheme 100. Combinational chemistry was applied in the Rh-catalyzed asymmetric hydrogenation of conjugate alkenes. Mixing of one chiral monophosphorus ligand and another chiral/achiral monophosphorus ligand enabled a quick approach to access a variety of different ligand screening. Some interesting results were obtained in the Rh-catalyzed asymmetric hydrogenation174 and attracted further mechanistic study.174c In 2005, Feringa and co-workers174a reported the Rh-catalyzed asymmetric hydrogenation of disubstituted acrylic acids by mixing of a chiral monophosphoramidite ligand L120 and an achiral monophosphorus ligand, which gave a dramatic increase in conversion and in enantioselectivity compared to the corresponding homocomplexes (Scheme 101a). A single hydrogen-bonded

biaryl monophosphorus ligand BI-DIME. A series of chiral α-amino tertiary boronates were formed in good yields and excellent enantioselectivities. Mechanistic studies indicated that the N−H was crucial for the high activities of hydroboration (Scheme 94).

9. ASYMMETRIC HYDROGENATION Asymmetric hydrogenation remains one of most efficient and greenest methods in reducing prochiral alkenes, ketones, and imines into the corresponding chiral products. The key element for a highly enantioselective hydrogenation process is the proper choice of a metal and a ligand. A variety of chiral ligands were designed and successfully employed in the asymmetric hydrogenation process.3a−d,4d−j,165 Although bidentate ligands remain dominant in applications, the chiral monophosphorus ligands have shown high activities and enantioselectivities in many cases.4e,f,h,i This section will summarize the recent remarkable progress using chiral monophosphorus ligands. 9.1. Asymmetric Hydrogenation of Enamines/ Enamides. The results of Rh-catalyzed asymmetric hydrogenation of enamines and enamides since 2000 are summarized in Scheme 95.166 A variety of chiral monophosphorus ligands were developed, and good to excellent enantioselectivities were obtained. In addition, some promising results were also achieved through combinatorial chemistry,167 self-supported heterogeneous catalysts,168 switchable catalysts,169 and iridium catalysts.170 In 2003, Reetz and co-workers167a reported a Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid ester 346a by combining two different monophosphorus ligands. The heterocombinations showed better performance than homocombinations in some cases (Scheme 96a). Feringa and co-workers167b also reported similar results in hydrogenation of β-dehydroamino acid ester 9−356a (Scheme 96b). Ding and co-workers168a demonstrated a self-supported strategy in forming an enantioselective heterogeneous catalyst through assembly of a bridged monophosphoramidite ligand with Rh(I) ion for asymmetric hydrogenation of enamides, affording a variety of hydrogenation products in high yields and excellent enatioselectivities even after seven runs. The heterogeneous catalyst was easily recycled and provided better enantioselective control than the corresponding homogeneous

Scheme 101. Mixing of a Chiral Monophosphoramidite Ligand with an Achiral Monophosphorus Ligand

4848


Review

ACS Catalysis supramolecular ligand174b was developed by mixing the chiral monophosphoramidite ligand LEUPhos and an urea-phosphine L134, which was suggested by DFT calculation and applied in the Rh-catalyzed asymmetric hydrogenation to form Roche ester (3-hydroxy-2-methylpropionate) in excellent ee (Scheme 101b). In 2007, Reetz and co-workers175 employed a mixture of the chiral monophosphorus acid diester L136 and PPh3 in Ir-catalyzed asymmetric hydrogenation of ketimines, providing the hydrogenation products in high enantioselectivities, which outperformed the homocombinations. The chiral phosphorus acid diester was believed to tautomerize to structure A in its active catalyst (Scheme 102). In 2012, Ding and co-workers174c demonstrated that the chiral phosphorus acid diester L137 could be used as an efficient ligand in Rh-catalyzed hydrogenation of the α-substituted

ethenylphosphonic acids. Studies suggested that the chiral monophosphoramidite ligand L27 was likely to undergo hydrolysis under acidic conditions to generate the phosphine oxide L137, which proved to be the real efficient ligand for this transformation. The rhodium complex of L137 was prepared and isolated, and its structure was confirmed by X-ray crystallographic analysis. Two ligands of L137 were found to coordinate with the rhodium metal center through the phosphorus atoms in this complex, which provided excellent reactivities (catalytic loading as low as 0.01 mol %) and enantioselectivities in asymmetric hydrogenation (Scheme 103a). Using a similar catalyst system with a secondary phosphine oxide L138 as the chiral ligand, Ding and co-workers174f reported the Rh-catalyzed asymmetric hydrogenation of α-arylacrylic acids in high yields and enatioslectivities (Scheme 103b). By combining the chiral secondary phosphine oxide and an achiral monophosphorus ligand, Ding and co-workers174d,e developed the Rh-catalyzed asymmetric hydrogenation of substituted acrylic acids in high enantioselectivities (Scheme 104). The design of new chiral ligands is always one of the most important directions in asymmetric hydrogenation. In 2009, Reetz and co-workers176 reported a novel helical triskelion monophosphorus ligand L12 and applied it in the Rh-catalyzed asymmetric hydrogenation of homoallylic alcohols, providing chiral alcohols in high enantioselectivities (Scheme 105).

Scheme 102. Ir-Catalyzed Asymmetric Hydrogenation of Ketimines

10. CHIRAL MONOPHOSPHORUS LIGANDS FOR ORGANOCATALYSIS During the past decade, the application of chiral tertiary phosphorus ligands as enantioselective nucleophilic catalysts has grown rapidly,177 which has become one of most attractive methods in constructing multiple carbon−carbon, carbon− heteroatom bonds with good enantioselective control. This section summarized the use of chiral monophosphorus ligands as enantioselective nucleophilic catalysts in asymmetric formal [m+n] cycloaddition and asymmetric addition to allenes, alkynes, and enones. The chiral monophosphorus ligands applied in this area were summarized in Figure 3. Scheme 103. Rh-Catalyzed Asymmetric Hydrogenation with Secondary Phosphine Oxides

4849


Review

ACS Catalysis 10.1. Asymmetric [m+n] Cycloaddition. Lu’s pioneering work177j has demonstrated that the tertiary monophosphorus ligands can act as organocatalysts to promote the formal [3 + 2] cycloaddition of allenoates and alkenes. In 1997, Zhang and coworkers178 reported the first asymmetric [3 + 2] cycloaddition of allenoates and electron-deficient olefins catalyzed by a chiral monophosphorus ligand L148 (Scheme 106a). Since then, this research area has expanded rapidly with the development of

some highly active chiral monophosphorus ligands. Their applications in the formal [3 + 2],178,179 [4 + 2],180 [4 + 1],181 and [3 + 3]182 cycloadditions were summarized in Scheme 106, Scheme 108, Scheme 110, and Scheme 112 respectively. For asymmetric [3 + 2] cycloaddition, electron-deficient terminal allenes or disubstituted internal allenes were employed as the three-carbon coupling partners and electron-deficient olefins as the two-carbon coupling partners. A variety of substituted cyclopentenes were prepared in good yields and enantioselectivities. Besides the widely used chiral binaphthyl and spiro ligands, some novel chiral monophosphorus ligands possessing interesting skeletons were developed including the FerroPHAE ligands developed by Marinetti and co-workers179b−d and L2 developed by Kwon and co-workers.179g Besides the intermolecular [3 + 2] cycloaddition, an intramolecular [3 + 2] cycloaddition of allenoates and olefins was developed by Fu and co-workers179h in 2015 with the use of chiral monophosphorus ligand L141. A series of bicyclic products were obtained in high yields and excellent enantioselectivities (Scheme 106j). Experimental results suggested the ring formation occurred via a concerted fashion. A plausible mechanism179f−i for this asymmetric [3 + 2] cycloaddition of allenoates and olefins was proposed as follows: (i) the cyclioaddition commenced with the formation of a zwitterionic intermediate between the allenoate and ligand; (ii) the intermediate acted as a 1,3-dipole and underwent a concerted [3 + 2] cycloaddition with olefin to give a phosphorus ylide, followed by the H shift and elimination, providing the substituted cyclopentenes; (iii) two regio-isomers were obtained due to the different 1,3-dipole, which generally favored the formation of intermediate T46 (Scheme 107). By using a disubstituted terminal allenoates with an acidic hydrogen atom at the substituent such as substrates 417a and 417b, the formal [4 + 2] cycloaddition proceeded smoothly with substituted imines. Fu180a and Sasai180b independently reported enantioselective formal [4 + 2] cycloaddition catalyzed by chiral monophosphorus ligands L18 and L24, respectively, to form chiral heterocycles in good yields and enantioselectivities (Scheme 108). A similar activation model was proposed and one major regio-isomer was favored (addition of 4 Å MS increased the regioselective ratio by Sasai) (Scheme 109). Asymmetric [3 + 2] and [4 + 2] reaction catalyzed by chiral monophosphorus ligands suffered from the formation of regioisomeric side-products. In order to avoid this complication, the

Scheme 104. Rh-Catalyzed Asymmetric Hydrogenation of Substituted Acrylic Acids

Scheme 105. Rh-Catalyzed Asymmetric Hydrogenation of Homoallylic Alcohols

Figure 3. Chiral monophosphorus ligands used for asymmetric organocatalysis. 4850


Review

ACS Catalysis Scheme 106. Asymmetric [3 + 2] Cycloaddition Catalyzed by Chiral Monophosphorus Ligands

cyclopentenes.181a Chiral dihydropyrroles181b were also formed with primary amines as the nucleophiles (Scheme 110). Mechanistic studies suggested that the activation model was through a diene ylide intermediate (Scheme 111).

enantioselective [4 + 1] annulation was developed by using disubstituted terminal allenoates bearing a good leaving group as the substrate. Fu and co-workers reported an asymmetric [4 + 1] cycloaddition of a procarbon nucleophile to provide substituted 4851


Review

ACS Catalysis Scheme 107. Plausible Mechanism of [3 + 2] Cycloaddition

Scheme 108. Chiral Monophosphorus Ligands Catalyzed Asymmetric [4 + 2] Cycloaddition


The pioneering work from Kwon182a and Lu182b demonstrated that phosphorus ligands catalyzed [3 + 3] cycloaddition was also a powerful tool to synthesis six-membered-rings. However, until 2015, Guo and co-workers182f reported the first chiral monophosphorus ligand-catalyzed enantioselective [3 + 3] cycloaddition of MBH carbonates with C,N-cyclic azomethine imines to give a class of dinitrogen-fused heterocycles in good yields with excellent ee’s (Scheme 112).

10.2. Asymmetric Addition to Alkynes, Allenes. Monophosphorus ligands do not only promote the annulations of allenoates and olefins but also act as catalysts in promoting addition of nucleophiles to alkynes and allenoates. The pioneering

Scheme 109. Plausible Mechanism of [4 + 2] Cycloaddition

4852


Review

ACS Catalysis work of Trost and co-workers183 described a dppp-catalyzed cyclization of hydroxyl-2-alkynoates to form oxygenated heterocycles. An asymmetric intermolecular addition of prochiral carbon nucleophiles to alkynoates was developed by Zhang and co-workers184 by using a chiral monophosphorus ligand L148. The highly enantioselective version was reported by Fu and co-workers185 using SITCP L24 as the chiral ligand, which led to

the formations of heterocycles in good yields and enantioselectivities (Scheme 113). Mechanistically, this reaction could be expanded to the allenoates substrates. Possible isomerization side-products could be detected if the substrates possessed a δ hydrogen186 (Scheme 114). The substrate scope was expanded rapidly, with the applicability of a variety of C186,187-, S188-, N189-, and O185,190-nucleophiles developed by Fu and Sasai (summarized in Scheme 115). In 2015, Sasai and co-workers190 developed a highly stereoselective chiral monophosphorus ligand-catalyzed oxy-Michael/Rauhut− Currier reaction, providing a series of highly functionalized tetrahydrobenzofuranones bearing chiral quaternary stereogenic centers in up to 96% ee. 10.3. Asymmetric Morita−Baylis−Hillman Reactions. The Morita−Baylis−Hillman reaction has become one of the most useful methods to construct C−C bonds, and the asymmetric version was also expanded rapidly. The bifunctional catalysts were recently designed for MBH/aza-MBH reactions. A Lewis base and a Brønsted acid were crafted onto one chiral backbone to act cooperatively in the MBH reaction cycle.177k−m However, the chiral monophosphorus ligands were found useful for MBH/aza-MBH reactions with only few examples.191 In 2013, Štěpnička and co-workers191c reported the asymmetric aza-MBH reaction of methyl vinyl ketone and aldimine 441a in 94% ee with a moderate yield (due to the poor chemoselectivity) by using a chiral monophosphorus ligand L148 as the ligand (Scheme 116a). By using a P-chiral monophosphorus ligand L149, Sasai and co-workers expanded the substrates to ketimines, providing the products with quaternary stereocenters in good to excellent yields and ee’s (Scheme 116b).

Scheme 111. Plausible Mechanism of [4 + 1] Cycloaddition


■

CONCLUSIONS AND OUTLOOK It is without any doubt that the chiral monophosphorus ligands have played a significant role for the recent advances in various asymmetric catalytic transformations such as asymmetric allylic substitution, asymmetric dearomative arylation, asymmetric Heck reaction, asymmetric cross-coupling, asymmetric C−H bond functionalization, asymmetric coupling of π systems, asymmetric addition, asymmetric hydrogenation, organocatalytic reaction, and many others. Significant progress has been achieved thanks to the development of the extremely versatile chiral monophosphoramidite ligands that have shown numerous applications in various asymmetric catalytic reactions. Encouragingly, the P-chiral monophosphorus ligands have also shown increasingly more applications, adding a different category in the repertoire of efficient chiral monophosphorus ligands. Further explorations of new chiral monophosphorus ligands are destined

Scheme 113. Intramolecular Asymmetric Addition of Alkynoates

Scheme 114. Mechanism of γ-Addition to Alkynoates/Allenoates Catalyzed by Monophosphorus Ligands

4853


Review

ACS Catalysis Scheme 115. Asymmetric Addition to Allenoates Catalyzed by Chiral Monophosphorus Ligands

■

Scheme 116. Chiral-Monophosphorus-Ligand-Catalyzed Asymmetric aza-MBH Reactions

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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REFERENCES

(1) (a) Noyori, R. Asymmetric catalysis in organic synthesis; Wiley: New York, 1993;. (b) Collins, A. N.; Gary, Sheldrake; Crosby, J. Chirality in industry: II: Developments in the commercial manufacture and applications of optically active compounds; Wiley: Chichester, 1997. (2) Kamer, P. C. J.; Leeuwen, P. W. N. M. V. Phosphorus(III) ligands in homogeneous catalysis: Design and synthesis; Wiley: Chichester, 2012. (3) (a) Knowles, W. S. Angew. Chem., Int. Ed. 2002, 41, 1998−2007. (b) Knowles, W. S. Adv. Synth. Catal. 2003, 345, 3−13. (c) Tang, W.; Zhang, X. Chem. Rev. 2003, 103, 3029−3069. (d) Zhang, W.; Chi, Y.; Zhang, X. Acc. Chem. Res. 2007, 40, 1278−1290. (e) Diéguez, M.; Pàmies, O. Acc. Chem. Res. 2010, 43, 312−322. (4) (a) Guerrero Rios, I.; Rosas-Hernandez, A.; Martin, E. Molecules 2011, 16, 970. (b) Feringa, B. L. Acc. Chem. Res. 2000, 33, 346−353. (c) Pedroni, J.; Cramer, N. Chem. Commun. (Cambridge, U. K.) 2015, 51, 17647−17657. (d) Liu, G.; Xu, G.; Luo, R.; Tang, W. Synlett 2013, 24, 2465−2471. (e) Komarov, I. V.; Borner, A. Angew. Chem., Int. Ed. 2001, 40, 1197−1200. (f) Jerphagnon, T.; Renaud, J.-L.; Bruneau, C. Tetrahedron: Asymmetry 2004, 15, 2101−2111. (g) Xie, J.-H.; Zhu, S.F.; Fu, Y.; Hu, A.-G.; Zhou, Q.-L. Pure Appl. Chem. 2005, 77, 2121− 2132. (h) Minnaard, A. J.; Feringa, B. L.; Lefort, L.; de Vries, J. G. Acc. Chem. Res. 2007, 40, 1267−1277. (i) Eberhardt, L.; Armspach, D.; Harrowfield, J.; Matt, D. Chem. Soc. Rev. 2008, 37, 839−864. (j) Hu, X.P.; Wang, D.-S.; Yu, C.-B.; Zhou, Y.-G.; Zheng, Z. Top. Organomet. Chem. 2011, 36, 313−354. (k) Teichert, J. F.; Feringa, B. L. Angew. Chem., Int. Ed. 2010, 49, 2486−2528. (5) Knowles, W. S.; Sabacky, M. J.; Vineyard, B. D. J. Chem. Soc., Chem. Commun. 1972, 10−11. (6) Morrison, J. D.; Burnett, R. E.; Aguiar, A. M.; Morrow, C. J.; Phillips, C. J. Am. Chem. Soc. 1971, 93, 1301−1303. (7) (a) van Leeuwen, P. W. N. M.; Kamer, P. C. J.; Claver, C.; Pàmies, O.; Diéguez, M. Chem. Rev. 2011, 111, 2077−2118. (b) Gladiali, S.; Alberico, E.; Junge, K.; Beller, M. Chem. Soc. Rev. 2011, 40, 3744−3763.

to provide new reactivity, selectivity, and mechanism in asymmetric catalysis with the emergence of many practical and efficient asymmetric chemical processes. Despite the current progress in asymmetric catalysis, many asymmetric catalytic reactions are still far from ideal and not applicable for green synthesis. For many currently known transformations, there remain numerous unsolved problems including narrow substrate scope, high catalyst loading, low selectivity and reactivity et al. Numerous interesting transformations are yet to be discovered or at the budding stage of exploration. It is therefore of importance to continue the design and exploration of chiral monophosphorus ligands with various structural features. Such practice should continue for a long period of time in the area of asymmetric catalysis. 4854


Review

ACS Catalysis (c) Hayashi, T. Acc. Chem. Res. 2000, 33, 354−362. (d) Lagasse, F.; Kagan, H. B. Chem. Pharm. Bull. 2000, 48, 315−324. (e) Hayashi, T. Yuki Gosei Kagaku Kyokaishi 1994, 52, 900−911. (8) (a) Hartwig, J. F.; Stanley, L. M. Acc. Chem. Res. 2010, 43, 1461− 1475. (b) Tosatti, P.; Nelson, A.; Marsden, S. P. Org. Biomol. Chem. 2012, 10, 3147−3163. (9) Zhuo, C.-X.; Zheng, C.; You, S.-L. Acc. Chem. Res. 2014, 47, 2558− 2573. (10) Wu, Q.-F.; He, H.; Liu, W.-B.; You, S.-L. J. Am. Chem. Soc. 2010, 132, 11418−11419. (11) Wu, Q.-F.; Liu, W.-B.; Zhuo, C.-X.; Rong, Z.-Q.; Ye, K.-Y.; You, S.-L. Angew. Chem., Int. Ed. 2011, 50, 4455−4458. (12) Zhuo, C.-X.; Liu, W.-B.; Wu, Q.-F.; You, S.-L. Chem. Sci. 2012, 3, 205−208. (13) Wu, Q. F.; Zheng, C.; You, S. L. Angew. Chem., Int. Ed. 2012, 51, 1680−1683. (14) Zhuo, C.-X.; Wu, Q.-F.; Zhao, Q.; Xu, Q.-L.; You, S.-L. J. Am. Chem. Soc. 2013, 135, 8169−8172. (15) Yang, Z.-P.; Wu, Q.-F.; You, S.-L. Angew. Chem., Int. Ed. 2014, 53, 6986−6989. (16) Zhang, X.; Yang, Z. P.; Huang, L.; You, S. L. Angew. Chem., Int. Ed. 2015, 54, 1873−1876. (17) Zhuo, C.-X.; Cheng, Q.; Liu, W.-B.; Zhao, Q.; You, S.-L. Angew. Chem., Int. Ed. 2015, 54, 8475−8479. (18) Liu, W. B.; Zheng, C.; Zhuo, C. X.; Dai, L. X.; You, S. L. J. Am. Chem. Soc. 2012, 134, 4812−4821. (19) Zhang, X.; Liu, W.-B.; Tu, H.-F.; You, S.-L. Chem. Sci. 2015, 6, 4525−4529. (20) Zhuo, C. X.; Zhou, Y.; Cheng, Q.; Huang, L.; You, S. L. Angew. Chem., Int. Ed. 2015, 54, 14146−14149. (21) Yang, Z. P.; Wu, Q. F.; Shao, W.; You, S. L. J. Am. Chem. Soc. 2015, 137, 15899−15906. (22) Trost, B. M.; Ehmke, V.; O’Keefe, B. M.; Bringley, D. A. J. Am. Chem. Soc. 2014, 136, 8213−8216. (23) Huang, L.; Dai, L.-X.; You, S.-L. J. Am. Chem. Soc. 2016, 138, 5793−5796. (24) Chen, Z.; Jiang, Q.; Zhu, G.; Xiao, D.; Cao, P.; Guo, C.; Zhang, X. J. Org. Chem. 1997, 62, 4521−4523. (25) Hayashi, T.; Kawatsura, M.; Uozumi, Y. Chem. Commun. 1997, 561−562. (26) Graening, T.; Hartwig, J. F. J. Am. Chem. Soc. 2005, 127, 17192− 17193. (27) Weix, D. J.; Hartwig, J. F. J. Am. Chem. Soc. 2007, 129, 7720−7721. (28) Chen, W.; Hartwig, J. F. J. Am. Chem. Soc. 2012, 134, 15249− 15252. (29) (a) Chen, M.; Hartwig, J. F. Angew. Chem., Int. Ed. 2014, 53, 8691−8695. (b) Chen, M.; Hartwig, J. F. Angew. Chem., Int. Ed. 2014, 53, 12172−12176. (c) Chen, M.; Hartwig, J. F. J. Am. Chem. Soc. 2015, 137, 13972−13979. (30) Chen, W.; Hartwig, J. F. J. Am. Chem. Soc. 2013, 135, 2068−2071. (31) Chen, W.; Hartwig, J. F. J. Am. Chem. Soc. 2014, 136, 377−382. (32) (a) Liu, W. B.; Reeves, C. M.; Stoltz, B. M. J. Am. Chem. Soc. 2013, 135, 17298−17301. (b) Liu, W. B.; Reeves, C. M.; Virgil, S. C.; Stoltz, B. M. J. Am. Chem. Soc. 2013, 135, 10626−10629. (c) Chen, W.; Chen, M.; Hartwig, J. F. J. Am. Chem. Soc. 2014, 136, 15825−15828. (33) Fañanás-Mastral, M.; Pérez, M.; Bos, P. H.; Rudolph, A.; Harutyunyan, S. R.; Feringa, B. L. Angew. Chem., Int. Ed. 2012, 51, 1922−1925. (34) Hornillos, V.; Pérez, M.; Fañanás-Mastral, M.; Feringa, B. L. J. Am. Chem. Soc. 2013, 135, 2140−2143. (35) Fañanás-Mastral, M.; Vitale, R.; Pérez, M.; Feringa, B. L. Chem. Eur. J. 2015, 21, 4209−4212. (36) Misale, A.; Niyomchon, S.; Luparia, M.; Maulide, N. Angew. Chem., Int. Ed. 2014, 53, 7068−7073. (37) Turnbull, B. W.; Evans, P. A. J. Am. Chem. Soc. 2015, 137, 6156− 6159. (38) Ohmura, T.; Hartwig, J. F. J. Am. Chem. Soc. 2002, 124, 15164− 15165.

(39) (a) Kiener, C. A.; Shu, C.; Incarvito, C.; Hartwig, J. F. J. Am. Chem. Soc. 2003, 125, 14272−14273. (b) Leitner, A.; Shu, C.; Hartwig, J. F. Org. Lett. 2005, 7, 1093−1096. (c) Shekhar, S.; Trantow, B.; Leitner, A.; Hartwig, J. F. J. Am. Chem. Soc. 2006, 128, 11770−11771. (d) Yamashita, Y.; Gopalarathnam, A.; Hartwig, J. F. J. Am. Chem. Soc. 2007, 129, 7508− 7509. (e) Pouy, M. J.; Leitner, A.; Weix, D. J.; Ueno, S.; Hartwig, J. F. Org. Lett. 2007, 9, 3949−3952. (f) Weix, D. J.; Marković, D.; Ueda, M.; Hartwig, J. F. Org. Lett. 2009, 11, 2944−2947. (g) Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc. 2009, 131, 8971−8983. (h) Pouy, M. J.; Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc. 2009, 131, 11312−11313. (i) Stanley, L. M.; Hartwig, J. F. Angew. Chem., Int. Ed. 2009, 48, 7841− 7844. (j) Banerjee, D.; Junge, K.; Beller, M. Angew. Chem., Int. Ed. 2014, 53, 13049−13053. (k) Grange, R. L.; Clizbe, E. A.; Counsell, E. J.; Evans, P. A. Chem. Sci. 2015, 6, 777−781. (40) (a) López, F.; Ohmura, T.; Hartwig, J. F. J. Am. Chem. Soc. 2003, 125, 3426−3427. (b) Shu, C.; Hartwig, J. F. Angew. Chem., Int. Ed. 2004, 43, 4794−4797. (c) Lyothier, I.; Defieber, C.; Carreira, E. M. Angew. Chem., Int. Ed. 2006, 45, 6204−6207. (41) (a) Ueda, M.; Hartwig, J. F. Org. Lett. 2010, 12, 92−94. (b) Liu, W.; Zhao, X. M.; Zhang, H. B.; Zhang, L.; Zhao, M. Z. Chem. - Eur. J. 2014, 20, 16873−16876. (42) (a) Zeng, B. S.; Yu, X.; Siu, P. W.; Scheidt, K. A. Chem. Sci. 2014, 5, 2277−2281. (b) Wang, P. S.; Liu, P.; Zhai, Y. J.; Lin, H. C.; Han, Z. Y.; Gong, L. Z. J. Am. Chem. Soc. 2015, 137, 12732−12735. (43) (a) Zhao, D.; Fañanás-Mastral, M.; Chang, M.-C.; Otten, E.; Feringa, B. L. Chem. Sci. 2014, 5, 4216−4220. (b) Teichert, J. F.; Fañanás-Mastral, M.; Feringa, B. L. Angew. Chem., Int. Ed. 2011, 50, 688−691. (44) Madrahimov, S. T.; Markovic, D.; Hartwig, J. F. J. Am. Chem. Soc. 2009, 131, 7228−7229. (45) (a) Leitner, A.; Shu, C.; Hartwig, J. F. Proc. Natl. Acad. Sci. U. S. A. 2004, 101, 5830−5833. (b) Leitner, A.; Shekhar, S.; Pouy, M. J.; Hartwig, J. F. J. Am. Chem. Soc. 2005, 127, 15506−15514. (46) Marković, D.; Hartwig, J. F. J. Am. Chem. Soc. 2007, 129, 11680− 11681. (47) Stanley, L. M.; Bai, C.; Ueda, M.; Hartwig, J. F. J. Am. Chem. Soc. 2010, 132, 8918−8920. (48) (a) Zhuo, C.-X.; Zhang, W.; You, S.-L. Angew. Chem., Int. Ed. 2012, 51, 12662−12686. (b) Roche, S. P.; Youte Tendoung, J.-J.; Treguier, B. Tetrahedron 2015, 71, 3549−3591. (c) Wu, W.-T.; Zhang, L.; You, S.-L. Chem. Soc. Rev. 2016, 45, 1570−1580. (49) (a) Rousseaux, S.; García-Fortanet, J.; Del Aguila Sanchez, M. A.; Buchwald, S. L. J. Am. Chem. Soc. 2011, 133, 9282−9285. (b) GarcíaFortanet, J.; Kessler, F.; Buchwald, S. L. J. Am. Chem. Soc. 2009, 131, 6676−6677. (50) (a) Bedford, R. B.; Butts, C. P.; Haddow, M. F.; Osborne, R.; Sankey, R. F. Chem. Commun. 2009, 4832−4834. (b) Bedford, R. B.; Fey, N.; Haddow, M. F.; Sankey, R. F. Chem. Commun. 2011, 47, 3649− 3651. (51) (a) Wu, K.-J.; Dai, L.-X.; You, S.-L. Org. Lett. 2012, 14, 3772− 3775. (b) Xu, R.-Q.; Gu, Q.; Wu, W.-T.; Zhao, Z.-A.; You, S.-L. J. Am. Chem. Soc. 2014, 136, 15469−15472. (52) Du, K.; Guo, P.; Chen, Y.; Cao, Z.; Wang, Z.; Tang, W. Angew. Chem., Int. Ed. 2015, 54, 3033−3037. (53) Cao, Z.; Du, K.; Liu, J.; Tang, W. Tetrahedron 2016, 72, 1782− 1786. (54) (a) Dounay, A. B.; Overman, L. E. Chem. Rev. 2003, 103, 2945− 2963. (b) Shibasaki, M.; Vogl, E. M.; Ohshima, T. Adv. Synth. Catal. 2004, 346, 1533−1552. (c) McCartney, D.; Guiry, P. J. Chem. Soc. Rev. 2011, 40, 5122−5150. (55) Imbos, R.; Minnaard, A. J.; Feringa, B. L. J. Am. Chem. Soc. 2002, 124, 184−185. (56) Imbos, R.; Minnaard, A. J.; Feringa, B. L. Dalton Trans. 2003, 2017−2023. (57) Kamikawa, K.; Harada, K.; Uemura, M. Tetrahedron: Asymmetry 2005, 16, 1419−1423. (58) Yasui, Y.; Takeda, H.; Takemoto, Y. Chem. Pharm. Bull. 2008, 56, 1567−1574. 4855


Review

ACS Catalysis (59) Cherney, A. H.; Kadunce, N. T.; Reisman, S. E. Chem. Rev. 2015, 115, 9587−9652. (60) Hayashi, T.; Hayashizaki, K.; Kiyoi, T.; Ito, Y. J. Am. Chem. Soc. 1988, 110, 8153−8156. (61) Jensen, J. F.; Johannsen, M. Org. Lett. 2003, 5, 3025−3028. (62) Willis, M. C.; Powell, L. H.; Claverie, C. K.; Watson, S. J. Angew. Chem., Int. Ed. 2004, 43, 1249−1251. (63) Urbaneja, X.; Mercier, A.; Besnard, C.; Kuendig, E. P. Chem. Commun. 2011, 47, 3739−3741. (64) Kamei, T.; Sato, A. H.; Iwasawa, T. Tetrahedron Lett. 2011, 52, 2638−2641. (65) Jumde, V. R.; Iuliano, A. Tetrahedron: Asymmetry 2011, 22, 2151− 2155. (66) (a) Wang, S.; Li, J.; Miao, T.; Wu, W.; Li, Q.; Zhuang, Y.; Zhou, Z.; Qiu, L. Org. Lett. 2012, 14, 1966−1969. (b) Tang, W.; Patel, N. D.; Xu, G.; Xu, X.; Savoie, J.; Ma, S.; Hao, M.-H.; Keshipeddy, S.; Capacci, A. G.; Wei, X.; Zhang, Y.; Gao, J. J.; Li, W.; Rodriguez, S.; Lu, B. Z.; Yee, N. K.; Senanayake, C. H. Org. Lett. 2012, 14, 2258−2261. (67) Zhou, Y.; Zhang, X.; Liang, H.; Cao, Z.; Zhao, X.; He, Y.; Wang, S.; Pang, J.; Zhou, Z.; Ke, Z.; Qiu, L. ACS Catal. 2014, 4, 1390−1397. (68) Zhou, Y.; Wang, S.; Wu, W.; Li, Q.; He, Y.; Zhuang, Y.; Li, L.; Pang, J.; Zhou, Z.; Qiu, L. Org. Lett. 2013, 15, 5508−5511. (69) Xu, G.; Fu, W.; Liu, G.; Senanayake, C. H.; Tang, W. J. Am. Chem. Soc. 2014, 136, 570−573. (70) Yang, X.; Xu, G.; Tang, W. Tetrahedron 2016, DOI: 10.1016/ j.tet.2015.12.051. (71) Hamada, T.; Chieffi, A.; Åhman, J.; Buchwald, S. L. J. Am. Chem. Soc. 2002, 124, 1261−1268. (72) Taylor, A. M.; Altman, R. A.; Buchwald, S. L. J. Am. Chem. Soc. 2009, 131, 9900−9901. (73) (a) Åhman, J.; Wolfe, J. P.; Troutman, M. V.; Palucki, M.; Buchwald, S. L. J. Am. Chem. Soc. 1998, 120, 1918−1919. (b) Lee, S.; Hartwig, J. F. J. Org. Chem. 2001, 66, 3402−3415. (c) Chen, G.; Kwong, F. Y.; Chan, H. O.; Yu, W.-Y.; Chan, A. S. C. Chem. Commun. 2006, 1413−1415. (d) Xie, X.; Chen, Y.; Ma, D. J. Am. Chem. Soc. 2006, 128, 16050−16051. (e) García-Fortanet, J.; Buchwald, S. L. Angew. Chem., Int. Ed. 2008, 47, 8108−8111. (f) Liao, X.; Weng, Z.; Hartwig, J. F. J. Am. Chem. Soc. 2008, 130, 195−200. (g) Taylor, A. M.; Altman, R. A.; Buchwald, S. L. J. Am. Chem. Soc. 2009, 131, 9900−9901. (74) Huang, Z.; Liu, Z.; Zhou, J. J. Am. Chem. Soc. 2011, 133, 15882− 15885. (75) Chau, S. T.; Lutz, J. P.; Wu, K.; Doyle, A. G. Angew. Chem., Int. Ed. 2013, 52, 9153−9156. (76) Shields, J. D.; Ahneman, D. T.; Graham, T. J. A.; Doyle, A. G. Org. Lett. 2014, 16, 142−145. (77) Zhu, Y.; Buchwald, S. L. J. Am. Chem. Soc. 2014, 136, 4500−4503. (78) Sun, C.; Potter, B.; Morken, J. P. J. Am. Chem. Soc. 2014, 136, 6534−6537. (79) Sun, H. Y.; Kubota, K.; Hall, D. G. Chem. - Eur. J. 2015, 21, 19186−19194. (80) Schuster, C. H.; Coombs, J. R.; Kasun, Z. A.; Morken, J. P. Org. Lett. 2014, 16, 4420−4423. (81) Saget, T.; Lemouzy, S. J.; Cramer, N. Angew. Chem., Int. Ed. 2012, 51, 2238−2242. (82) Saget, T.; Cramer, N. Angew. Chem., Int. Ed. 2012, 51, 12842− 12845. (83) Pedroni, J.; Saget, T.; Donets, P. A.; Cramer, N. Chem. Sci. 2015, 6, 5164−5171. (84) Pedroni, J.; Boghi, M.; Saget, T.; Cramer, N. Angew. Chem., Int. Ed. 2014, 53, 9064−9067. (85) Pedroni, J.; Cramer, N. Angew. Chem., Int. Ed. 2015, 54, 11826− 11829. (86) Albicker, M. R.; Cramer, N. Angew. Chem., Int. Ed. 2009, 48, 9139−9142. (87) Saget, T.; Cramer, N. Angew. Chem., Int. Ed. 2013, 52, 7865−7868. (88) Liu, L.; Zhang, A. A.; Zhao, R. J.; Li, F.; Meng, T. J.; Ishida, N.; Murakami, M.; Zhao, W. X. Org. Lett. 2014, 16, 5336−5338. (89) Lin, Z. Q.; Wang, W. Z.; Yan, S. B.; Duan, W. L. Angew. Chem., Int. Ed. 2015, 54, 6265−6269.

(90) Liu, L.; Zhang, A. A.; Wang, Y.; Zhang, F.; Zuo, Z.; Zhao, W. X.; Feng, C. L.; Ma, W. Org. Lett. 2015, 17, 2046−2049. (91) Xu, G.; Li, M.; Wang, S.; Tang, W. Org. Chem. Front. 2015, 2, 1342−1345. (92) Trost, B. M.; Thaisrivongs, D. A.; Donckele, E. J. Angew. Chem., Int. Ed. 2013, 52, 1523−1526. (93) (a) Montgomery, J.; Amarasinghe, K. K. D.; Chowdhury, S. K.; Oblinger, E.; Seo, J.; Savchenko, A. V. Pure Appl. Chem. 2002, 74, 129− 133. (b) Montgomery, J. Angew. Chem., Int. Ed. 2004, 43, 3890−3908. (c) Montgomery, J.; Sormunen, G. J. Top. Curr. Chem. 2007, 279, 1−23. (d) Moslin, R. M.; Miller-Moslin, K.; Jamison, T. F. Chem. Commun. 2007, 4441−4449. (e) Ng, S. S.; Ho, C. Y.; Schleicher, K. D.; Jamison, T. F. Pure Appl. Chem. 2008, 80, 929−939. (f) Tasker, S. Z.; Standley, E. A.; Jamison, T. F. Nature 2014, 509, 299−309. (g) Standley, E. A.; Tasker, S. Z.; Jensen, K. L.; Jamison, T. F. Acc. Chem. Res. 2015, 48, 1503−1514. (94) Miller, K. M.; Huang, W.-S.; Jamison, T. F. J. Am. Chem. Soc. 2003, 125, 3442−3443. (95) Miller, K. M.; Colby, E. A.; Woodin, K. S.; Jamison, T. F. Adv. Synth. Catal. 2005, 347, 1533−1536. (96) Yang, Y.; Zhu, S.-F.; Zhou, C.-Y.; Zhou, Q.-L. J. Am. Chem. Soc. 2008, 130, 14052−14053. (97) Nie, M.; Fu, W.; Cao, Z.; Tang, W. Org. Chem. Front. 2015, 2, 1322−1325. (98) Saito, N.; Kobayashi, A.; Sato, Y. Angew. Chem., Int. Ed. 2012, 51, 1228−1231. (99) Patel, S. J.; Jamison, T. F. Angew. Chem., Int. Ed. 2004, 43, 3941− 3944. (100) Miller, K. M.; Jamison, T. F. Org. Lett. 2005, 7, 3077−3080. (101) Fu, W.; Nie, M.; Wang, A.; Cao, Z.; Tang, W. Angew. Chem., Int. Ed. 2015, 54, 2520−2524. (102) (a) López, F.; Mascareñas, J. L. Beilstein J. Org. Chem. 2013, 9, 2250−2264. (b) Wang, Y.-M.; Lackner, A. D.; Toste, F. D. Acc. Chem. Res. 2014, 47, 889−901. (103) Alonso, I.; Trillo, B.; López, F.; Montserrat, S.; Ujaque, G.; Castedo, L.; Lledós, A.; Mascareñas, J. L. J. Am. Chem. Soc. 2009, 131, 13020−13030. (104) González, A. Z.; Toste, F. D. Org. Lett. 2010, 12, 200−203. (105) González, A. Z.; Benitez, D.; Tkatchouk, E.; Goddard, W. A.; Toste, F. D. J. Am. Chem. Soc. 2011, 133, 5500−5507. (106) Alonso, I.; Faustino, H.; López, F.; Mascareñas, J. L. Angew. Chem., Int. Ed. 2011, 50, 11496−11500. (107) Teller, H.; Flügge, S.; Goddard, R.; Fürstner, A. Angew. Chem., Int. Ed. 2010, 49, 1949−1953. (108) Teller, H.; Corbet, M.; Mantilli, L.; Gopakumar, G.; Goddard, R.; Thiel, W.; Fürstner, A. J. Am. Chem. Soc. 2012, 134, 15331−15342. (109) Suárez-Pantiga, S.; Hernández-Díaz, C.; Rubio, E.; González, J. M. Angew. Chem., Int. Ed. 2012, 51, 11552−11555. (110) Yavari, K.; Aillard, P.; Zhang, Y.; Nuter, F.; Retailleau, P.; Voituriez, A.; Marinetti, A. Angew. Chem., Int. Ed. 2014, 53, 861−865. (111) Qian, D.; Hu, H.; Liu, F.; Tang, B.; Ye, W.; Wang, Y.; Zhang, J. Angew. Chem., Int. Ed. 2014, 53, 13751−13755. (112) Wang, Y.; Zhang, P.; Qian, D.; Zhang, J. Angew. Chem., Int. Ed. 2015, 54, 14849−14852. (113) Fan, B.-M.; Xie, J.-H.; Li, S.; Tu, Y.-Q.; Zhou, Q.-L. Adv. Synth. Catal. 2005, 347, 759−762. (114) (a) Yu, R. T.; Rovis, T. J. Am. Chem. Soc. 2006, 128, 12370− 12371. (b) Yu, R. T.; Rovis, T. J. Am. Chem. Soc. 2008, 130, 3262−3263. (c) Lee, E. E.; Rovis, T. Org. Lett. 2008, 10, 1231−1234. (115) (a) Yu, R. T.; Lee, E. E.; Malik, G.; Rovis, T. Angew. Chem., Int. Ed. 2009, 48, 2379−2382. (b) Yu, R. T.; Friedman, R. K.; Rovis, T. J. Am. Chem. Soc. 2009, 131, 13250−13251. (116) Friedman, R. K.; Rovis, T. J. Am. Chem. Soc. 2009, 131, 10775− 10782. (117) (a) Perreault, S.; Rovis, T. Chem. Soc. Rev. 2009, 38, 3149−3159. (b) Friedman, R. K.; Oberg, K. M.; Dalton, D. M.; Rovis, T. Pure Appl. Chem. 2010, 82, 1353−1364. (118) Dalton, D. M.; Oberg, K. M.; Yu, R. T.; Lee, E. E.; Perreault, S.; Oinen, M. E.; Pease, M. L.; Malik, G.; Rovis, T. J. Am. Chem. Soc. 2009, 131, 15717−15728. 4856


Review

ACS Catalysis (119) Oberg, K. M.; Rovis, T. J. Am. Chem. Soc. 2011, 133, 4785−4787. (120) Dalton, D. M.; Rappe, A. K.; Rovis, T. Chem. Sci. 2013, 4, 2062− 2070. (121) (a) Dalton, D. M.; Rovis, T. Org. Lett. 2013, 15, 2346−2349. (b) Martin, T. J.; Rovis, T. Angew. Chem., Int. Ed. 2013, 52, 5368−5371. (122) Zhang, W. Z.; Chu, J. C.; Oberg, K. M.; Rovis, T. J. Am. Chem. Soc. 2015, 137, 553−555. (123) Shintani, R.; Takagi, C.; Ito, T.; Naito, M.; Nozaki, K. Angew. Chem., Int. Ed. 2015, 54, 1616−1620. (124) Shintani, R.; Takano, R.; Nozaki, K. Chem. Sci. 2016, 7, 1205− 1211. (125) (a) Wilsily, A.; Fillion, E. Org. Lett. 2008, 10, 2801−2804. (b) Fillion, E.; Wilsily, A. J. Am. Chem. Soc. 2006, 128, 2774−2775. (126) (a) Müller, D.; Hawner, C.; Tissot, M.; Palais, L.; Alexakis, A. Synlett 2010, 2010, 1694−1698. (b) Wilsily, A.; Fillion, E. J. Org. Chem. 2009, 74, 8583−8594. (c) Ladjel, C.; Fuchs, N.; Zhao, J.; Bernardinelli, G.; Alexakis, A. Eur. J. Org. Chem. 2009, 2009, 4949−4955. (d) Palais, L.; Alexakis, A. Chem. - Eur. J. 2009, 15, 10473−10485. (e) Hawner, C.; Li, K.; Cirriez, V.; Alexakis, A. Angew. Chem., Int. Ed. 2008, 47, 8211−8214. (f) Vuagnoux-d’Augustin, M.; Alexakis, A. Chem. - Eur. J. 2007, 13, 9647−9662. (g) Palais, L.; Mikhel, I. S.; Bournaud, C.; Micouin, L.; Falciola, C. A.; Vuagnoux-d’Augustin, M.; Rosset, S.; Bernardinelli, G.; Alexakis, A. Angew. Chem., Int. Ed. 2007, 46, 7462−7465. (h) d’Augustin, M.; Palais, L.; Alexakis, A. Angew. Chem., Int. Ed. 2005, 44, 1376−1378. (127) Hawner, C.; Alexakis, A. Chem. Commun. 2010, 46, 7295−7306. (128) Willcox, D.; Woodward, S.; Alexakis, A. Chem. Commun. 2014, 50, 1655−1657. (129) Esquivias, J.; Arrayás, R. G.; Carretero, J. C. J. Org. Chem. 2005, 70, 7451−7454. (130) Palacios, F.; Vicario, J. Org. Lett. 2006, 8, 5405−5408. (131) Westmeier, J.; von Zezschwitz, P. Chem. Commun. 2014, 50, 15897−15900. (132) Maciver, E. E.; Maksymowicz, R. M.; Wilkinson, N.; Roth, P. M.; Fletcher, S. P. Org. Lett. 2014, 16, 3288−3291. (133) Roth, P. M.; Fletcher, S. P. Org. Lett. 2015, 17, 912−915. (134) Rideau, E.; Mäsing, F.; Fletcher, S. P. Synthesis 2015, 47, 2217− 2222. (135) Sieber, J. D.; Liu, S.; Morken, J. P. J. Am. Chem. Soc. 2007, 129, 2214−2215. (136) Sieber, J. D.; Morken, J. P. J. Am. Chem. Soc. 2008, 130, 4978− 4983. (137) Brozek, L. A.; Sieber, J. D.; Morken, J. P. Org. Lett. 2011, 13, 995−997. (138) Liao, Y.-X.; Xing, C.-H.; Israel, M.; Hu, Q.-S. Org. Lett. 2011, 13, 2058−2061. (139) Wu, C.; Yue, G.; Nielsen, C. D.; Xu, K.; Hirao, H.; Zhou, J. S. J. Am. Chem. Soc. 2016, 138, 742−745. (140) (a) Facchetti, S.; Cavallini, I.; Funaioli, T.; Marchetti, F.; Iuliano, A. Organometallics 2009, 28, 4150−4158. (b) Iuliano, A.; Facchetti, S.; Funaioli, T. Chem. Commun. 2009, 457−459. (c) Jumde, V. R.; Iuliano, A. Adv. Synth. Catal. 2013, 355, 3475−3483. (141) (a) Lee, A.; Ahn, S.; Kang, K.; Seo, M.-S.; Kim, Y.; Kim, W. Y.; Kim, H. Org. Lett. 2014, 16, 5490−5493. (b) Lee, A.; Kim, H. J. Am. Chem. Soc. 2015, 137, 11250−11253. (142) Tian, P.; Dong, H.-Q.; Lin, G.-Q. ACS Catal. 2012, 2, 95−119. (143) Hayashi, T.; Ishigedani, M. J. Am. Chem. Soc. 2000, 122, 976− 977. (144) Jagt, R. B. C.; Toullec, P. Y.; Geerdink, D.; de Vries, J. G.; Feringa, B. L.; Minnaard, A. J. Angew. Chem., Int. Ed. 2006, 45, 2789− 2791. (145) Duan, H.-F.; Jia, Y.-X.; Wang, L.-X.; Zhou, Q.-L. Org. Lett. 2006, 8, 2567−2569. (146) Shintani, R.; Inoue, M.; Hayashi, T. Angew. Chem., Int. Ed. 2006, 45, 3353−3356. (147) Martina, S. L. X.; Jagt, R. B. C.; de Vries, J. G.; Feringa, B. L.; Minnaard, A. J. Chem. Commun. 2006, 4093−4095. (148) Duan, H.-F.; Xie, J.-H.; Qiao, X.-C.; Wang, L.-X.; Zhou, Q.-L. Angew. Chem., Int. Ed. 2008, 47, 4351−4353.

(149) (a) Duan, H.-F.; Xie, J.-H.; Shi, W.-J.; Zhang, Q.; Zhou, Q.-L. Org. Lett. 2006, 8, 1479−1481. (b) Xing, C.-H.; Liao, Y.-X.; He, P.; Hu, Q.-S. Chem. Commun. 2010, 46, 3010−3012. (150) Zhang, P.; Morken, J. P. J. Am. Chem. Soc. 2009, 131, 12550− 12551. (151) Li, K.; Hu, N.; Luo, R.; Yuan, W.; Tang, W. J. Org. Chem. 2013, 78, 6350−6355. (152) Joannou, M. V.; Moyer, B. S.; Meek, S. J. J. Am. Chem. Soc. 2015, 137, 6176−6179. (153) Shirakura, M.; Suginome, M. Angew. Chem., Int. Ed. 2010, 49, 3827−3829. (154) Luo, R.; Liao, J.; Xie, L.; Tang, W.; Chan, A. S. C. Chem. Commun. 2013, 49, 9959−9961. (155) Luo, R.; Xie, L.; Liao, J.; Xin, H.; Chan, A. S. C. Tetrahedron: Asymmetry 2014, 25, 709−717. (156) Shen, X.; Buchwald, S. L. Angew. Chem., Int. Ed. 2010, 49, 564− 567. (157) Hopkins, B. A.; Wolfe, J. P. Angew. Chem., Int. Ed. 2012, 51, 9886−9890. (158) Hopkins, B. A.; Garlets, Z. J.; Wolfe, J. P. Angew. Chem., Int. Ed. 2015, 54, 13390−13392. (159) Hu, N.; Li, K.; Wang, Z.; Tang, W. Angew. Chem., Int. Ed. 2016, 55, 5044−5048. (160) (a) Pelz, N. F.; Woodward, A. R.; Burks, H. E.; Sieber, J. D.; Morken, J. P. J. Am. Chem. Soc. 2004, 126, 16328−16329. (b) Woodward, A. R.; Burks, H. E.; Chan, L. M.; Morken, J. P. Org. Lett. 2005, 7, 5505−5507. (c) Pelz, N. F.; Morken, J. P. Org. Lett. 2006, 8, 4557−4559. (d) Sieber, J. D.; Morken, J. P. J. Am. Chem. Soc. 2006, 128, 74−75. (161) (a) Burks, H. E.; Kliman, L. T.; Morken, J. P. J. Am. Chem. Soc. 2009, 131, 9134−9135. (b) Schuster, C. H.; Li, B.; Morken, J. P. Angew. Chem., Int. Ed. 2011, 50, 7906−7909. (c) Hong, K.; Morken, J. P. J. Org. Chem. 2011, 76, 9102−9108. (162) (a) Kliman, L. T.; Mlynarski, S. N.; Morken, J. P. J. Am. Chem. Soc. 2009, 131, 13210−13211. (b) Kliman, L. T.; Mlynarski, S. N.; Ferris, G. E.; Morken, J. P. Angew. Chem., Int. Ed. 2012, 51, 521−524. (c) Coombs, J. R.; Haeffner, F.; Kliman, L. T.; Morken, J. P. J. Am. Chem. Soc. 2013, 135, 11222−11231. (d) Mlynarski, S. N.; Schuster, C. H.; Morken, J. P. Nature 2014, 505, 386−390. (e) Coombs, J. R.; Zhang, L.; Morken, J. P. J. Am. Chem. Soc. 2014, 136, 16140−16143. (f) Blaisdell, T. P.; Morken, J. P. J. Am. Chem. Soc. 2015, 137, 8712−8715. (163) Ohmura, T.; Taniguchi, H.; Suginome, M. J. Am. Chem. Soc. 2006, 128, 13682−13683. (164) Hu, N.; Zhao, G.; Zhang, Y.; Liu, X.; Li, G.; Tang, W. J. Am. Chem. Soc. 2015, 137, 6746−6749. (165) (a) Cui, X.; Burgess, K. Chem. Rev. 2005, 105, 3272−3296. (b) Dieguez, M.; Pamies, O.; Claver, C. Top. Organomet. Chem. 2011, 34, 11−29. (c) Fan, Q.-H.; Ding, K. Top. Organomet. Chem. 2011, 36, 207−246. (d) Etayo, P.; Vidal-Ferran, A. Chem. Soc. Rev. 2013, 42, 728− 754. (166) (a) Reetz, M. T.; Mehler, G. Angew. Chem., Int. Ed. 2000, 39, 3889−3890. (b) van den Berg, M.; Minnaard, A. J.; Schudde, E. P.; van Esch, J.; de Vries, A. H. M.; de Vries, J. G.; Feringa, B. L. J. Am. Chem. Soc. 2000, 122, 11539−11540. (c) Fu, Y.; Xie, J.-H.; Hu, A.-G.; Zhou, H.; Wang, L.-X.; Zhou, Q.-L. Chem. Commun. 2002, 480−481. (d) Zeng, Q.; Liu, H.; Cui, X.; Mi, A.; Jiang, Y.; Li, X.; Choi, M. C. K.; Chan, A. S. C. Tetrahedron: Asymmetry 2002, 13, 115−117. (e) Hu, A.-G.; Fu, Y.; Xie, J.-H.; Zhou, H.; Wang, L.-X.; Zhou, Q.-L. Angew. Chem., Int. Ed. 2002, 41, 2348−2350. (f) Van den Berg, M.; Haak, R. M.; Minnaard, A. J.; De Vries, A. H. M.; De Vries, J. G.; Feringa, B. L. Adv. Synth. Catal. 2002, 344, 1003−1007. (g) Jia, X.; Guo, R.; Li, X.; Yao, X.; Chan, A. S. C. Tetrahedron Lett. 2002, 43, 5541−5544. (h) Pena, D.; Minnaard, A. J.; de Vries, J. G.; Feringa, B. L. J. Am. Chem. Soc. 2002, 124, 14552−14553. (i) Jia, X.; Li, X.; Xu, L.; Shi, Q.; Yao, X.; Chan, A. S. C. J. Org. Chem. 2003, 68, 4539−4541. (j) Zhu, S.-F.; Fu, Y.; Xie, J.-H.; Liu, B.; Xing, L.; Zhou, Q.-L. Tetrahedron: Asymmetry 2003, 14, 3219−3224. (k) Fu, Y.; Guo, X.-X.; Zhu, S.-F.; Hu, A.-G.; Xie, J.-H.; Zhou, Q.-L. J. Org. Chem. 2004, 69, 4648−4655. (l) Fu, Y.; Hou, G.-H.; Xie, J.-H.; Xing, L.; Wang, L.-X.; Zhou, Q.-L. J. Org. Chem. 2004, 69, 8157−8160. (m) Wu, S.; Zhang, W.; Zhang, Z.; Zhang, X. Org. Lett. 2004, 6, 3565−3567. 4857


Review

ACS Catalysis

(179) (a) Wilson, J. E.; Fu, G. C. Angew. Chem., Int. Ed. 2006, 45, 1426−1429. (b) Voituriez, A.; Panossian, A.; Fleury-Brégeot, N.; Retailleau, P.; Marinetti, A. J. Am. Chem. Soc. 2008, 130, 14030−14031. (c) Voituriez, A.; Panossian, A.; Fleury-Brégeot, N.; Retailleau, P.; Marinetti, A. Adv. Synth. Catal. 2009, 351, 1968−1976. (d) Voituriez, A.; Pinto, N.; Neel, M.; Retailleau, P.; Marinetti, A. Chem. - Eur. J. 2010, 16, 12541−12544. (e) Fujiwara, Y.; Fu, G. C. J. Am. Chem. Soc. 2011, 133, 12293−12297. (f) Steurer, M.; Jensen, K. L.; Worgull, D.; Jørgensen, K. A. Chem. - Eur. J. 2012, 18, 76−79. (g) Henry, C. E.; Xu, Q.; Fan, Y. C.; Martin, T. J.; Belding, L.; Dudding, T.; Kwon, O. J. Am. Chem. Soc. 2014, 136, 11890−11893. (h) Lee, S. Y.; Fujiwara, Y.; Nishiguchi, A.; Kalek, M.; Fu, G. C. J. Am. Chem. Soc. 2015, 137, 4587−4591. (i) Wang, D.; Wang, G.-P.; Sun, Y.-L.; Zhu, S.-F.; Wei, Y.; Zhou, Q.-L.; Shi, M. Chem. Sci. 2015, 6, 7319−7325. (180) (a) Wurz, R. P.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 12234− 12235. (b) Takizawa, S.; Arteaga, F. A.; Yoshida, Y.; Suzuki, M.; Sasai, H. Asian J. Org. Chem. 2014, 3, 412−415. (181) (a) Ziegler, D. T.; Riesgo, L.; Ikeda, T.; Fujiwara, Y.; Fu, G. C. Angew. Chem., Int. Ed. 2014, 53, 13183−13187. (b) Kramer, S.; Fu, G. C. J. Am. Chem. Soc. 2015, 137, 3803−3806. (182) (a) Guo, H.; Xu, Q.; Kwon, O. J. Am. Chem. Soc. 2009, 131, 6318−6319. (b) Zheng, S.; Lu, X. Tetrahedron Lett. 2009, 50, 4532− 4535. (c) Na, R.; Jing, C.; Xu, Q.; Jiang, H.; Wu, X.; Shi, J.; Zhong, J.; Wang, M.; Benitez, D.; Tkatchouk, E.; Goddard, W. A.; Guo, H.; Kwon, O. J. Am. Chem. Soc. 2011, 133, 13337−13348. (d) Hu, J.; Dong, W.; Wu, X.-Y.; Tong, X. Org. Lett. 2012, 14, 5530−5533. (e) Liu, J.; Liu, H.; Na, R.; Wang, G.; Li, Z.; Yu, H.; Wang, M.; Zhong, J.; Guo, H. Chem. Lett. 2012, 41, 218−220. (f) Zhang, L.; Liu, H.; Qiao, G.; Hou, Z.; Liu, Y.; Xiao, Y.; Guo, H. J. Am. Chem. Soc. 2015, 137, 4316−4319. (g) Li, Z.; Yu, H.; Liu, Y.; Zhou, L.; Sun, Z.; Guo, H. Adv. Synth. Catal. 2016, 358, 1880−1885. (h) Liang, L.; Huang, Y. Org. Lett. 2016, 18, 2604−2607. (183) Trost, B. M.; Li, C.-J. J. Am. Chem. Soc. 1994, 116, 10819−10820. (184) Chen, Z.; Zhu, G.; Jiang, Q.; Xiao, D.; Cao, P.; Zhang, X. J. Org. Chem. 1998, 63, 5631−5635. (185) Chung, Y. K.; Fu, G. C. Angew. Chem., Int. Ed. 2009, 48, 2225− 2227. (186) Smith, S. W.; Fu, G. C. J. Am. Chem. Soc. 2009, 131, 14231− 14233. (187) (a) Sinisi, R.; Sun, J.; Fu, G. C. Proc. Natl. Acad. Sci. U. S. A. 2010, 107, 20652−20654. (b) Kalek, M.; Fu, G. C. J. Am. Chem. Soc. 2015, 137, 9438−9442. (188) Fujiwara, Y.; Sun, J.; Fu, G. C. Chem. Sci. 2011, 2, 2196−2198. (189) Lundgren, R. J.; Wilsily, A.; Marion, N.; Ma, C.; Chung, Y. K.; Fu, G. C. Angew. Chem., Int. Ed. 2013, 52, 2525−2528. (190) Takizawa, S.; Kishi, K.; Yoshida, Y.; Mader, S.; Arteaga, F. A.; Lee, S.; Hoshino, M.; Rueping, M.; Fujita, M.; Sasai, H. Angew. Chem., Int. Ed. 2015, 54, 15511−15515. (191) (a) Tang, H.; Cheng, X.; Zhang, Z. Phosphorus, Sulfur Silicon Relat. Elem. 2012, 187, 8−15. (b) Takizawa, S.; Remond, E.; Arteaga, F. A.; Yoshida, Y.; Sridharan, V.; Bayardon, J.; Juge, S.; Sasai, H. Chem. Commun. 2013, 49, 8392−8394. (c) Štěpnička, P.; Škoch, K.; Císařová, I. Organometallics 2013, 32, 623−635.

(n) Bernsmann, H.; van den Berg, M.; Hoen, R.; Minnaard, A. J.; Mehler, G.; Reetz, M. T.; de Vries, J. G.; Feringa, B. L. J. Org. Chem. 2005, 70, 943−951. (o) Liu, Y.; Ding, K. J. Am. Chem. Soc. 2005, 127, 10488−10489. (p) Zeng, Q.-H.; Hu, X.-P.; Duan, Z.-C.; Liang, X.-M.; Zheng, Z. J. Org. Chem. 2006, 71, 393−396. (q) Panella, L.; Aleixandre, A. M.; Kruidhof, G. J.; Robertus, J.; Feringa, B. L.; De Vries, J. G.; Minnaard, A. J. J. Org. Chem. 2006, 71, 2026−2036. (r) Hou, G.-H.; Xie, J.-H.; Wang, L.-X.; Zhou, Q.-L. J. Am. Chem. Soc. 2006, 128, 11774− 11775. (s) Huo, X.-H.; Xie, J.-H.; Wang, Q.-S.; Zhou, Q.-L. Adv. Synth. Catal. 2007, 349, 2477−2484. (t) Zhang, J.; Li, Y.; Wang, Z.; Ding, K. Angew. Chem., Int. Ed. 2011, 50, 11743−11747. (167) (a) Reetz, M. T.; Sell, T.; Meiswinkel, A.; Mehler, G. Angew. Chem., Int. Ed. 2003, 42, 790−793. (b) Pena, D.; Minnaard, A. J.; Boogers, J. A. F.; de Vries, A. H. M.; de Vries, J. G.; Feringa, B. L. Org. Biomol. Chem. 2003, 1, 1087−1089. (168) (a) Wang, X.; Ding, K. J. Am. Chem. Soc. 2004, 126, 10524− 10525. (b) Shi, L.; Wang, X.; Sandoval, C. A.; Wang, Z.; Li, H.; Wu, J.; Yu, L.; Ding, K. Chem. - Eur. J. 2009, 15, 9855−9867. (c) Yu, L.; Wang, Z.; Wu, J.; Tu, S.; Ding, K. Angew. Chem., Int. Ed. 2010, 49, 3627−3630. (169) Ouyang, G.-H.; He, Y.-M.; Li, Y.; Xiang, J.-F.; Fan, Q.-H. Angew. Chem., Int. Ed. 2015, 54, 4334−4337. (170) Giacomina, F.; Meetsma, A.; Panella, L.; Lefort, L.; de Vries, A. H. M.; de Vries, J. G. Angew. Chem., Int. Ed. 2007, 46, 1497−1500. (171) (a) Huang, H.; Liu, X.; Deng, J.; Qiu, M.; Zheng, Z. Org. Lett. 2006, 8, 3359−3362. (b) Duan, Z.-C.; Hu, X.-P.; Wang, D.-Y.; Huang, J.-D.; Yu, S.-B.; Deng, J.; Zheng, Z. Adv. Synth. Catal. 2008, 350, 1979− 1983. (c) Duan, Z.-C.; Hu, X.-P.; Zhang, C.; Wang, D.-Y.; Yu, S.-B.; Zheng, Z. J. Org. Chem. 2009, 74, 9191−9194. (d) Zhang, J.; Dong, K.; Wang, Z.; Ding, K. Org. Biomol. Chem. 2012, 10, 1598−1601. (172) (a) Junge, K.; Hagemann, B.; Enthaler, S.; Oehme, G.; Michalik, M.; Monsees, A.; Riermeier, T.; Dingerdissen, U.; Beller, M. Angew. Chem., Int. Ed. 2004, 43, 5066−5069. (b) Xu, Y.; Alcock, N. W.; Clarkson, G. J.; Docherty, G.; Woodward, G.; Wills, M. Org. Lett. 2004, 6, 4105−4107. (c) Xu, Y.; Clarkson, G. C.; Docherty, G.; North, C. L.; Woodward, G.; Wills, M. J. Org. Chem. 2005, 70, 8079−8087. (d) Stegink, B.; van Boxtel, L.; Lefort, L.; Minnaard, A. J.; Feringa, B. L.; de Vries, J. G. Adv. Synth. Catal. 2010, 352, 2621−2628. (173) Hou, G.; Tao, R.; Sun, Y.; Zhang, X.; Gosselin, F. J. Am. Chem. Soc. 2010, 132, 2124−2125. (174) (a) Hoen, R.; Boogers, J. A. F.; Bernsmann, H.; Minnaard, A. J.; Meetsma, A.; Tiemersma-Wegman, T. D.; de Vries, A. H. M.; de Vries, J. G.; Feringa, B. L. Angew. Chem., Int. Ed. 2005, 44, 4209−4212. (b) Breuil, P.-A. R.; Patureau, F. W.; Reek, H. N. H. Angew. Chem., Int. Ed. 2009, 48, 2162−2165. (c) Dong, K.; Wang, Z.; Ding, K. J. Am. Chem. Soc. 2012, 134, 12474−12477. (d) Li, Y.; Dong, K.; Wang, Z.; Ding, K. Angew. Chem., Int. Ed. 2013, 52, 6748−6752. (e) Dong, K.; Li, Y.; Wang, Z.; Ding, K. Angew. Chem., Int. Ed. 2013, 52, 14191−14195. (f) Dong, K.; Li, Y.; Wang, Z.; Ding, K. Org. Chem. Front. 2014, 1, 155. (175) Reetz, M. T.; Bondarev, O. Angew. Chem., Int. Ed. 2007, 46, 4523−4526. (176) Reetz, M. T.; Guo, H.; Ma, J.-A.; Goddard, R.; Mynott, R. J. J. Am. Chem. Soc. 2009, 131, 4136−4142. (177) (a) Xiao, Y.; Sun, Z.; Guo, H.; Kwon, O. Beilstein J. Org. Chem. 2014, 10, 2089−2121. (b) Fan, Y. C.; Kwon, O. Chem. Commun. 2013, 49, 11588−11619. (c) Wei, Y.; Shi, M. Chem. Rev. 2013, 113, 6659− 6690. (d) Wei, Y.; Shi, M. Acc. Chem. Res. 2010, 43, 1005−1018. (e) Cowen, B. J.; Miller, S. J. Chem. Soc. Rev. 2009, 38, 3102−3116. (f) Ma, G.-N.; Jiang, J.-J.; Shi, M.; Wei, Y. Chem. Commun. 2009, 5496− 5514. (g) Declerck, V.; Martinez, J.; Lamaty, F. Chem. Rev. 2009, 109, 1−48. (h) Masson, G.; Housseman, C.; Zhu, J. Angew. Chem., Int. Ed. 2007, 46, 4614−4628. (i) Methot, J. L.; Roush, W. R. Adv. Synth. Catal. 2004, 346, 1035−1050. (j) Lu, X.; Zhang, C.; Xu, Z. Acc. Chem. Res. 2001, 34, 535−544. (k) Wei, Y.; Shi, M. In Comprehensive Enantioselective Organocatalysis; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, 2013; pp 899−939. (l) Wei, Y.; Shi, M. Chem. - Asian J. 2014, 9, 2720−2734. (m) Zhou, R.; He, Z. Eur. J. Org. Chem. 2016, 1937−1954. (178) Zhu, G.; Chen, Z.; Jiang, Q.; Xiao, D.; Cao, P.; Zhang, X. J. Am. Chem. Soc. 1997, 119, 3836−3837. 4858


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