Copper-Catalyzed Asymmetric Reductive Allylation of Ketones with 1

4 hours ago - This method provides a straightforward and alternative avenue to synthesize chiral homoallylic tertiary alcohols with 1,3-dienes as the ...
0 downloads 0 Views 1MB Size
Download PDF
Letter Cite This: Org. Lett. XXXX, XXX, XXX−XXX

pubs.acs.org/OrgLett

Copper-Catalyzed Asymmetric Reductive Allylation of Ketones with 1,3-Dienes Bin Fu,† Xiuping Yuan,† Yanfei Li,† Ying Wang,† Qian Zhang,† Tao Xiong,*,† and Qian Zhang†,‡ †

Downloaded via UNIV AUTONOMA DE COAHUILA on May 6, 2019 at 18:45:32 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China ‡ State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China S Supporting Information *

ABSTRACT: A catalytic chemo-, regio-, and enantioselective allylation of ketones with 1,3 dienes in the presence of (R,R)-PhBPE ligated Cu catalyst and hydrosilane is presented. This method provides a straightforward and alternative avenue to synthesize chiral homoallylic tertiary alcohols with 1,3-dienes as the latent allylic nucleophiles and avoids the traditional reliance on stoichiometric quantities of allylmetal reagents. This transformation proceeds under very mild conditions and displays good functional group tolerance and could be performed on a gram-scale.

O

Scheme 1. Transition-Metal-Catalyzed Reductive Coupling of Unsaturated Hydrocarbons with Ketones

ptically pure homoallylic alcohols and their derivatives are widely founded within a diverse range of important pharmaceuticals and biologically active natural products.1 Consequently, it is of great significance for synthetic chemists to develop new approaches for the synthesis of these skeletons in a stereoselective manner. Among these approaches,2 relying heavily on the prior preparation of stoichiometric quantities of the allylmetal reagents along with generation of metal salts waste in these processes significantly limits the functional group tolerance and synthetic efficiency.1a In addition, lacking extensive methods or requiring tedious synthetic steps to synthesize allylmetallics, especially for highly functionalized allylmetallics, also restricts their widespread application. As pioneered by Krische for over a decade,3b the development of a catalytic method for effective generation of allylic nucleophiles from easily accessible and stable feedstocks as the allylic metal reagent equivalents could circumvent the drawbacks of preformed allylmetallics and is particularly appealing. The utility of stable and easily accessible 1,3-dienes in lieu of allylmetal reagents for addition to carbonyls would be an ideal strategy for access to homoallylic alcohols.3 In this regard, Gendre and Moïse disclosed the first example on Ti-catalyzed racemic allylation reaction of aldehydes with dienes in 2005 despite low diastereoselectivities in most cases.4 Subsequently, Krische and coworkers realized the allylation of dienes with alcohols or aldehydes by precious metal Rh, Ru, and Ir catalysis.5−7 Additionally, the groups of Tamaru, Ogoshi, Breit, and Krische also developed earth-abundant first-row transitionmetal Ni-catalyzed reductive coupling of 1,3-dienes with aldehydes (Scheme 1, A).8 While these reports mainly focused on high reactivity aldehydes as the coupling partners, the more challenging addition of dienes to ketones, especially in an enantioselective fashion, remains elusive so far, partly due to © XXXX American Chemical Society

the increased steric hindrance, attenuated reactivity profile, and minimal enantiomorphic face differentiation of ketones compared with aldehydes. In addition to dienes as the latent allylic metal reagents, some elegant approaches on enantioselective addition of other unsaturated hydrocarbon-derived nucleophiles, including alkenylazaarenes, conjugated enynes, allenes, 1,4-enyne, and 2-azadiene to ketones, to form chiral tertiary alcohols have been disclosed in the past few years (Scheme 1, B);9 however, the asymmetric reductive allylation of ketones with 1,3-dienes remains unexploited. As part of our Received: March 20, 2019

A

DOI: 10.1021/acs.orglett.9b00979 Org. Lett. XXXX, XXX, XXX−XXX

Letter

Organic Letters Table 1. Optimization of Reaction Conditionsa

continuing interest in CuH chemistry,10 we describe a Cucatalyzed highly diastereo- and enantioselective reductive allylation of ketones with easily accessible 1,3-dienes as latent allylic nucleophiles to furnish a series of synthetically important chiral homoallylic tertiary alcohols (Scheme 1, C). We note that during the preparation of this manuscript, Liu, Buchwald, and coworkers reported an elegant CuH-catalyzed asymmetric ketone allylation with 1,3-dienes. In their approach, which mainly focused on the coupling of ketones with butadiene, isoprene, and cyclohexadiene, one example of 2-aryl substituted 1,3-diene was reported.11 We initiated our studies by evaluating the addition reaction between acetophenone 2a and unsymmetrical 2-phenyl-1,3diene 1a, which had acute challenges in terms of regiocontrol in Cu catalysis.12 To our delight, the expected allylation reaction of ketone 2a proceeded in the presence of (R,R)-MeDuPhos L1 ligated Cu(OAc)2 as the catalyst and 3.0 equiv DMMS as the hydride source in THF at 20 °C, affording the desired product 3a in 64% yield, despite low level of enantioselectivity along with 35% reduction product 1phenylethanol as by product (Table 1, entry 1). Changing methyl to sterically bulky iso-propyl group on the DuPhos skeleton resulted in almost the same yield and slightly improved enantioselectivity, and 36% 1-phenylethanol was also observed (Table 1, entry 2). To further improve the yield and enantiocontrol, the ligand L2 was switched to (R,R)-PhBPE L3, which has demonstrated excellent performance in CuH chemistry,13 and the yield and ee value were dramatically improved, furnishing product 3a in 93% yield and 93% ee (Table 1, entry 3). Compared with (R,R)-Ph-BPE L3, other chiral bisphosphine ligands such as L4−L6 exhibited lower or no reactivity profiles (Table 1, entries 4−6). Subsequently, evaluation of various hydrosilanes, including PMHS, (MeO)3SiH, PhSiH3, and PhMeSiH2 was performed and generally showed high reactivity and only tiny difference on enantioselectivity (Table 1, entries 7−10). Likewise, replacement of THF with other solvents such as dioxane, toluene, diethyl ether, and cyclohexane resulted in slightly lower yields but almost the same high level of enantioselectivity (Table 1, entries 11−14). It is noteworthy that all the reactions showed excellent diastereoselectivities (>20:1 dr). With the optimized conditions established, we proceeded to examine the substrate scope of this reductive allylation of ketones. As indicated in Scheme 2, a wide range of substituted aryl methyl ketones 2 were found to be suitable substrates under the mild conditions and furnished corresponding homoallylic tertiary alcohols in good to excellent yields and enantioselectivities as well as generally high diastereoselectivities. For instance, a variety of electron-donating substituents on the aromatic rings of the ketones, including alkoxyl (2b− 2e), free hydroxyl (2f), alkyl (2g−2i), aryl, and acetonaphthone 2k, processed smoothly, affording corresponding products 3b−3k in the range of 81−95% yields, 82−94% ee values, and over 17:1 dr. In addition, higher enantioselectivity of meta- and para-OMe substituted ketones 2b and 2c compared to that of ortho-OMe acetophenone 2d was observed, probably due to the steric hindrance. Besides ketones bearing electron-donating functional groups, electron-withdrawing substituents on the aromatic rings of the ketones such as −Cl, −Br, −CF3, and even for −I were also valid substrates and provided expected products 3l−3q with excellent enantioselectivities and dr along with 38% reduction product alcohol of ketone 2q under the present catalytic

a

Reaction conditions: 1,3-diene 1 (0.4 mmol, 2.0 equiv), ketone 2 (0.2 mmol, 1 equiv), Cu(OAc)2 (5 mol %), ligand (6 mol %), and hydrosilane (0.6 mmol, 3.0 equiv) in 1 mL dry solvent for 18 h at 20 °C. DMMS: Me(MeO)2SiH; PMHS: polymethylhydrosiloxane; TMDS: (Me2SiH)2O; N.D.: not detected. bYield and diastereomeric ratio (dr) were determined by 1H NMR spectroscopy of the crude mixture with methylene bromide as an internal standard. cDetermined by HPLC analysis.

system. Furthermore, heteroaryl methyl ketones 2r and 2s, cyclic ketones 2t and 2u, dialkyl substituted ketone 2v, and propiophenone 2w all allylated smoothly with 2-phenyl-1,3diene 1a in generally good yields and optical purity, but low ee value was observed for 3w. However, when methyl pyruvate 2x was subjected to the reaction conditions, no allylation was observed, and only the corresponding reduction product was isolated. We further explored the scope of 1,3-dienes. Reaction of dienes substituted with either electron-rich (1y−1ac) or electron-deficient (1ad−1ag) aryl groups all proceeded well, delivering corresponding chiral tertiary alcohols 3y−3ag in good to excellent yields with over 90% ee and >20:1 dr in most cases. Additionally, 2-heteroaryl substituted diene 1ah was also a suitable substrate for this allylation reaction. To our delight, simple conjugated dienes such as isoprene and cyclohexadiene as the allylmetal surrogates also exhibited high reactivity and were successfully converted to desired products 3ai−3ak in moderate to good yields, while major isomer of 3ai is racemic under the present catalytic conditions.14 To highlight the synthetic utility of this asymmetric reductive allylation of ketone, we performed a gram-scale B

DOI: 10.1021/acs.orglett.9b00979 Org. Lett. XXXX, XXX, XXX−XXX

Letter

Organic Letters Scheme 2. Substrate Scopea,b,c

a

Reaction conditions: 1,3-diene 1 (0.4 mmol, 2.0 equiv), ketone 2 (0.2 mmol, 1 equiv), Cu(OAc)2 (5 mol %), ligand (6 mol %), and DMMS (0.6 mmol, 3.0 equiv) in 1 mL dry THF for 18 h at 20 °C. bIsolated yield and ee value was determined by HPLC analysis. cDiastereomeric ratio (dr) was determined by 1H NMR spectroscopy of the crude mixture. dMajor isomer.

further transformations of obtained alcohol 3a were also briefly examined to prove its synthetic potential (Scheme 3). The hydroxyl group moiety is versatile and could be esterified with methacryloyl chloride, providing ester 4 bearing an activated C−C double bond, which provides an opportunity for further elaboration. In addition, the C−C double bond in 3aj could also be easily dihydroxylated under mild conditions, affording triol product 5 in 80% yield as a single diastereomer.15 The proposed catalytic cycle of this Cu-catalyzed asymmetric allylation of ketones is shown in Scheme 4. The addition of the in situ generation of (R,R)-Ph-BPE ligated CuH complexes I, which are derived from the reductive reaction of chiral ligand ligated Cu(OAc)2 with hydrosilane, to 1,3-diene enabled the catalytic formation of allyl copper intermediate II. The intermediate II would be likely to rapidly isomerize to allyl copper species III. Then, a highly regio- and stereoselective addition of the allyl copper intermediate to ketone occurred, offering the copper alkoxide IV through a sixmembered transition state.9c−f,h,11,16 Then, a σ-bond metathesis reaction between intermediate IV and hydrosilane should rapidly regenerate the L*CuH catalyst, concomitantly affording the silylated homoallylic tertiary alcohol V. Finally,

reaction of 1a (1.62 g, 1.5 equiv) with ketone 2a (1.0 g, 8.3 mmol) (Scheme 3). The target optically active alcohol 3a was obtained in 80% yield without any erosion in enantioselectivity in the presence of a lower catalyst loading (1 mol % Cu(OAc)2, 1.1 mol %. chiral ligand, Scheme 3). In addition, Scheme 3. Gram-Scale Synthesis and Applications of Chiral Homoallylic Tertiary Alcohol 3

C

DOI: 10.1021/acs.orglett.9b00979 Org. Lett. XXXX, XXX, XXX−XXX

Letter

Organic Letters

90−93. (e) Wang, Y.; Ju, W.; Tian, H.; Tian, W.; Gui, J. J. Am. Chem. Soc. 2018, 140, 9413−9416. (2) For recent reviews, see: (a) Riant, O.; Hannedouche, J. Org. Biomol. Chem. 2007, 5, 873−888. (b) Yus, M.; González-Gómez, J. C.; Foubelo, F. Chem. Rev. 2011, 111, 7774−7854. (c) Huo, H.-X.; Duvall, J. R.; Huang, M.-Y.; Hong, R. Org. Chem. Front. 2014, 1, 303− 320. (d) Liu, Y.-L.; Lin, X.-T. Adv. Synth. Catal. 2019, 361, 876. (3) (a) Jang, H.-Y.; Krische, M. J. Acc. Chem. Res. 2004, 37, 653− 661. (b) Ngai, M.-Y.; Kong, J.-R.; Krische, M. J. J. Org. Chem. 2007, 72, 1063−1072. (c) Bower, J. F.; Kim, I. S.; Patman, R. L. Angew. Chem., Int. Ed. 2009, 48, 34−46. (d) Ketcham, J. M.; Shin, I.; Montgomery, T. P.; Krische, M. J. Angew. Chem., Int. Ed. 2014, 53, 9142−9150. (e) Murphy, S. K.; Dong, V. M. Chem. Commun. 2014, 50, 13645−13649. (f) Nguyen, K. D.; Park, B.; Luong, Y.; Sato, T. H.; Garza, V. J.; Krische, M. J. Science 2016, 354, aah5133. (g) Pirnot, M. T.; Wang, Y.-M.; Buchwald, S. L. Angew. Chem., Int. Ed. 2016, 55, 48− 57. (h) Holmes, M.; Schwartz, L. A.; Krische, M. J. Chem. Rev. 2018, 118, 6026−6052. (i) Gui, Y.-Y.; Hu, N.; Chen, X.-W.; Liao, L.-L.; Ju, T.; Ye, J.-H.; Zhang, Z.; Li, J.; Yu, D.-G. J. Am. Chem. Soc. 2017, 139, 17011−17014 and also see ref 16h. . (4) Bareille, L.; Le Gendre, P.; Moïse, C. Chem. Commun. 2005, 775−777. (5) Rh catalysis, see: Jang, H.-Y.; Huddleston, R. R.; Krische, M. J. Angew. Chem., Int. Ed. 2003, 42, 4074−4077. (6) For Ru catalysis, see: (a) Shibahara, F.; Bower, J. F.; Krische, M. J. J. Am. Chem. Soc. 2008, 130, 6338−6339. (b) Zbieg, J. R.; Moran, J.; Krische, M. J. J. Am. Chem. Soc. 2011, 133, 10582−10586. (c) Zbieg, J. R.; Yamaguchi, E.; McInturff, E. L.; Krische, M. J. Science 2012, 336, 324−327. (d) McInturff, E. L.; Yamaguchi, E.; Krische, M. J. J. Am. Chem. Soc. 2012, 134, 20628−20631. (e) Leung, J. C.; Geary, L. M.; Chen, T.-Y.; Zbieg, J. R.; Krische, M. J. Direct. J. Am. Chem. Soc. 2012, 134, 15700−15703. (f) Park, B. Y.; Montgomery, T. P.; Garza, V. J.; Krische, M. J. J. Am. Chem. Soc. 2013, 135, 16320−16323. (g) Chen, T.-Y.; Krische, M. J. Org. Lett. 2013, 15, 2994−2997. (7) For Ir catalysis, see: (a) Bower, J. F.; Patman, R. L.; Krische, M. J. Org. Lett. 2008, 10, 1033−1035. (b) Zbieg, J. R.; Fukuzumi, T.; Krische, M. J. Adv. Synth. Catal. 2010, 352, 2416−2420. (c) Nguyen, K. D.; Herkommer, D.; Krische, M. J. J. Am. Chem. Soc. 2016, 138, 14210−14213. (8) For Ni catalysis, see: (a) Kimura, M.; Miyachi, A.; Kojima, K.; Tanaka, S.; Tamaru, Y. J. Am. Chem. Soc. 2004, 126, 14360−14361. (b) Kimura, M.; Ezoe, A.; Mori, M.; Iwata, K.; Tamaru, Y. J. Am. Chem. Soc. 2006, 128, 8559−8568. (c) Ogoshi, S.; Tonomori, K.-I.; Oka, M.-A.; Kurosawa, H. J. Am. Chem. Soc. 2006, 128, 7077−7086. (d) Kopfer, A.; Sam, B.; Breit, B.; Krische, M. J. Chem. Sci. 2013, 4, 1876−1880. (9) (a) Miller, K. M.; Jamison, T. F. Org. Lett. 2005, 7, 3077−3080. (b) Komanduri, V.; Krische, M. J. J. Am. Chem. Soc. 2006, 128, 16448−16449. (c) Saxena, A.; Choi, B.; Lam, H. W. J. Am. Chem. Soc. 2012, 134, 8428−8431. (d) Yang, Y.; Perry, I. B.; Lu, G.; Liu, P.; Buchwald, S. L. Science 2016, 353, 144−150. (e) Wei, X.-F.; Xie, X.W.; Shimizu, Y.; Kanai, M. J. Am. Chem. Soc. 2017, 139, 4647−4650. (f) Tsai, E. Y.; Liu, R. R.; Yang, Y.; Buchwald, S. L. A. J. Am. Chem. Soc. 2018, 140, 2007−2011. (g) Li, K.; Shao, X.; Tseng, L.; Malcolmson, S. J. J. Am. Chem. Soc. 2018, 140, 598−601. (h) Liu, R. R.; Zhou, Y.; Yang, Y.; Buchwald, S. L. J. Am. Chem. Soc. 2019, 141, 2251−2256. (10) (a) Xu, G.; Zhao, H.; Fu, B.; Cang, A.; Zhang, G.; Zhang, Q.; Xiong, T.; Zhang, Q. Angew. Chem., Int. Ed. 2017, 56, 13130−13134. (b) Xu, G.; Fu, B.; Zhao, H.; Li, Y.; Zhang, G.; Wang, Y.; Xiong, T.; Zhang, Q. Chem. Sci. 2019, 10, 1802−1806. (11) Li, C.; Liu, R. Y.; Jesikiewicz, L. T.; Yang, Y.; Liu, P.; Buchwald, S. L. J. Am. Chem. Soc. 2019, 141, 5062−5070. (12) (a) Jia, T.; He, Q.; Ruscoe, R. E.; Pulis, A. P.; Procter, D. J. Angew. Chem., Int. Ed. 2018, 57, 11305−11309. (b) Wen, L.; Zhang, H.; Wang, J.; Meng, F. Chem. Commun. 2018, 54, 12832−12835. (13) For selective recent examples, see: (a) Yang, Y.; Perry, I. B.; Buchwald, S. L. J. Am. Chem. Soc. 2016, 138, 9787−9790. (b) Wang, Y.-M.; Buchwald, S. L. J. Am. Chem. Soc. 2016, 138, 5024−5027.

Scheme 4. Proposed Catalytic Cycle

the expected product 3 was generated by simple workup with NH4F. In summary, we developed an efficient and straightforward approach for the synthesis of chiral homoallylic tertiary alcohols through Cu-catalyzed reductive allylation of ketones with 1,3-dienes. Using easily accessible 1,3-dienes and ketones as feedstocks, good functional group tolerance and the high chemo-, regio-, and stereoselectivity suggested that this approach might have tremendous potential for further applications. Further efforts toward the development of other types of asymmetric transformations of unsaturated hydrocarbons with first-row transition metal catalysts are currently underway in our lab.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.orglett.9b00979. Experimental details, spectral data, and copies of 1H and 13 C NMR and HPLC spectra for all products (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Tao Xiong: 0000-0002-2516-084X Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS We acknowledge the NSFC (Grants 21672033, 21831002, and 201118123), the Jilin Province Natural Science Foundation (Grant 20160520140JH), the Fundamental Research Funds for the Central Universities, and the Ten Thousand Talents Program for generous financial support.

■

REFERENCES

(1) For selected reviews, see: (a) Yus, M.; González-Gómez, J. C.; Foubelo, F. Chem. Rev. 2013, 113, 5595−5698. (b) Ameen, D.; Snape, T. J. MedChemComm 2013, 4, 893−907 For selected syntheses of natural products containing a homoallylic alcohol moiety, see: . (c) Gao, X.; Hall, D. G. J. Am. Chem. Soc. 2005, 127, 1628−1629. (d) Kawamura, S.; Chu, H.; Felding, J.; Baran, P. S. Nature 2016, 532, D

DOI: 10.1021/acs.orglett.9b00979 Org. Lett. XXXX, XXX, XXX−XXX

Letter

Organic Letters (c) Shao, X.; Li, K.; Malcolmson, S. J. J. Am. Chem. Soc. 2018, 140, 7083−7087. (d) Zhou, Y.; Bandar, J. S.; Buchwald, S. L. J. Am. Chem. Soc. 2017, 139, 8126−8129. (e) Gribble, M. W., Jr; Guo, S.; Buchwald, S. L. J. Am. Chem. Soc. 2018, 140, 5057−5060. (f) Zhou, Y.; Engl, O. D.; Bandar, J. S.; Chant, E. D.; Buchwald, S. L. Angew. Chem., Int. Ed. 2018, 57, 6672−6675. (14) We are aware that the reductive addition product of isoprene to ketone with 92% ee was obtained using JOSIPHOS derivative SLJ011-1 as chiral ligand, see ref 11. (15) (a) Ahmed, M. M.; O’Doherty, G. A. J. Org. Chem. 2005, 70, 10576−10578. (b) Robinson, T. V.; Taylor, D. K.; Tiekink, E. R. T. J. Org. Chem. 2006, 71, 7236−7244. (c) Valente, P.; Avery, T. D.; Taylor, D. K.; Tiekink, E. R. T. J. Org. Chem. 2009, 74, 274−282. (16) (a) Yang, Y.; Liu, P. ACS Catal. 2015, 5, 2944−2951. (b) Jiang, L.; Cao, P.; Wang, M.; Chen, B.; Wang, B.; Liao, J. Angew. Chem., Int. Ed. 2016, 55, 13854−13858. (c) Yeung, K.; Ruscoe, R. E.; Rae, J.; Pulis, A. P.; Procter, D. J. Angew. Chem., Int. Ed. 2016, 55, 11912− 11916. (d) Zhao, W.; Montgomery, J. J. Am. Chem. Soc. 2016, 138, 9763−9766. (e) Fujihara, T.; Sawada, A.; Yamaguchi, T.; Tani, Y.; Terao, J.; Tsuji, Y. Angew. Chem., Int. Ed. 2017, 56, 1539−1543. (f) Boreux, A.; Indukuri, K.; Gagosz, F.; Riant, O. ACS Catal. 2017, 7, 8200−8204. (g) Jang, H.; Romiti, F.; Torker, S.; Hoveyda, A. H. Nat. Chem. 2017, 9, 1269−1275. (h) Li, M.; Wang, J.; Meng, F. Org. Lett. 2018, 20, 7288−7292.

E

DOI: 10.1021/acs.orglett.9b00979 Org. Lett. XXXX, XXX, XXX−XXX