Synlett 2022; 33(18): 1863-1867
DOI: 10.1055/a-1892-4134
cluster
Development and Applications of Novel Ligands/Catalysts and Mechanistic Studies on Catalysis

Rhodium-Catalyzed Regio- and Enantioselective Direct Allylation of Methyl Ketones

Bing Li
,
Changkun Li
This work was supported by the National Natural Science Foundation of China (NSFC) (Grant 21602130).


Abstract

We report a highly branch-selective and enantioselective allylic alkylation of simple ketones with racemic aliphatic allylic carbonates under mild conditions. By using a Rh–bisoxazolinephosphine system and catalytic amounts of a base in THF, a series of chiral β-branched γ,δ-unsaturated ketones were obtained with excellent regio- and enantioselectivities. An outer-sphere nucleophilic substitution C–C bond-formation process is proposed on the basis of mechanistic studies.

Supporting Information



Publication History

Received: 05 May 2022

Accepted after revision: 05 July 2022

Accepted Manuscript online:
05 July 2022

Article published online:
30 September 2022

© 2022. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 
  • References and Notes


    • For selected examples, see:
    • 2a Helmchen G, Janssen JP. Tetrahedron Lett. 1997; 38: 8025
    • 2b Trost BM, Hildbrand S, Dogra K. J. Am. Chem. Soc. 1999; 121: 10416
    • 2c You S.-L, Zhu X.-Z, Luo Y.-M, Hou X.-L, Dai L.-X. J. Am. Chem. Soc. 2001; 123: 7471
    • 2d Trost BM, Dogra K, Hachiya I, Emura T, Hughes DL, Krska S, Reamer RA, Palucki M, Yasuda N, Reider PJ. Angew. Chem. Int. Ed. 2002; 41: 1929
    • 2e Kanayama T, Yoshida K, Miyabe H, Takemoto Y. Angew. Chem. Int. Ed. 2003; 42: 2054
    • 2f Schelwies M, Dübon P, Helmchen G. Angew. Chem. Int. Ed. 2006; 45: 2466
    • 2g Gnamm C, Förster S, Miller N, Brödner K, Helmchen G. Synlett 2007; 790
    • 2h He H, Zheng X.-J, Li Y, Dai L.-X, You S.-L. Org. Lett. 2007; 9: 4339
    • 2i Dübon P, Schelwies M, Helmchen G. Chem. Eur. J. 2008; 14: 6722
    • 2j Trost BM, Miller JR, Hoffman CM. Jr. J. Am. Chem. Soc. 2011; 133: 8165
    • 2k Liu W.-B, Reeves CM, Virgil SC, Stoltz BM. J. Am. Chem. Soc. 2013; 135: 10626
    • 2l Liu W.-B, Reeves CM, Stoltz BM. J. Am. Chem. Soc. 2013; 135: 17298
    • 2m Stanley LM, Bai C, Ueda M, Hartwig JF.
    • 2n He Z.-T, Jiang X, Hartwig JF. J. Am. Chem. Soc. 2019; 141: 13066
    • 2o Huo X, He R, Zhang X, Zhang W. J. Am. Chem. Soc. 2016; 138: 11093
    • 2p Huo X, Zhang J, Fu J, He R, Zhang W. J. Am. Chem. Soc. 2018; 140: 2080
    • 3a Bordwell FG. Acc. Chem. Res. 1988; 21: 456
    • 3b Bordwell FG, Cornforth FJ. J. Org. Chem. 1978; 43: 1763
  • 4 Evans PA, Leahy DK. J. Am. Chem. Soc. 2003; 125: 8974
    • 5a Graening T, Hartwig JF. J. Am. Chem. Soc. 2005; 127: 17192
    • 5b Weix DJ, Hartwig JF. J. Am. Chem. Soc. 2007; 129: 7720
    • 5c Liang X, Wei K, Yang Y.-R. Chem. Commun. 2015; 51: 17471
    • 5d Kanbayashi N, Yamazawa A, Takii K, Okamura T, Onitsuka K. Adv. Synth. Catal. 2016; 358: 555
  • 6 Yue B.-B, Deng Y, Zheng Y, Wei K, Yang Y.-R. Org. Lett. 2019; 21: 2449
  • 7 Tsuji J, Shimizu I, Minami I, Ohashi Y, Sugiura T, Takahashi K. J. Org. Chem. 1985; 50: 1523

    • For direct allylation of ketones from 1,3-dienes, see:
    • 8a Chen T, Yang H, Yang Y, Dong G, Xing D. ACS Catal. 2020; 10: 4238
    • 8b Cheng L, Li M.-M, Xiao L.-J, Xie J.-H, Zhou Q.-L. J. Am. Chem. Soc. 2018; 140: 11627

      For selected examples of the chirality control at ketones, see:
    • 9a Trost BM, Schroeder GM. J. Am. Chem. Soc. 1999; 121: 6759
    • 9b Trost BM, Schroeder GM, Kristensen J. Angew. Chem. Int. Ed. 2002; 41: 3492
    • 9c You S.-L, Hou X.-L, Dai L.-X, Zhu X.-Z. Org. Lett. 2001; 3: 149
    • 9d Yan X.-X, Liang C.-G, Zhang Y, Hong W, Cao B.-X, Dai L.-X, Hou X.-L. Angew. Chem. Int. Ed. 2005; 44: 6544
    • 9e Zheng W.-H, Zheng B.-H, Zhang Y, Hou X.-L. J. Am. Chem. Soc. 2007; 129: 7718

      For selected examples of Rh(I)/bisoxazolinephosphine catalyst systems, see:
    • 10a Xu W.-B, Ghorai S, Huang W, Li C. ACS Catal. 2020; 10: 4491
    • 10b Huang W.-Y, Lu C, Ghorai S, Li B, Li C. J. Am. Chem. Soc. 2020; 142: 15276
    • 10c Li K, Li C. Org. Lett. 2020; 22: 9456
    • 10d Liu M, Zhao H, Li C. Chin. Chem. Lett. 2021; 32: 385
    • 10e Sun M, Liu M, Li C. Chem. Eur. J. 2021; 27: 3457
    • 10f Xu W.-B, Sun M, Shu M, Li C. J. Am. Chem. Soc. 2021; 143: 8255
    • 10g Li B, Liu M, Ur Rehman S, Li C. J. Am. Chem. Soc. 2022; 144: 2893
  • 11 CCDC 2142005 contains the supplementary crystallographic data for compound 3gh. The data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.
  • 12 Chiral β-Branched γ,δ-Unsaturated Ketones 3; General ProcedureIn a N2-filled glovebox, a pressure tube equipped with a magnetic stirrer bar was charged with [Rh(cod)Cl]2 (1.3 mg, 1.25 mol%), NPNPh, iPr (3.0 mg, 3.0 mol%), and THF (1.0 mL), and the mixture was stirred at rt for 15 min. rac-1 (0.2 mmol, 1.0 equiv), 2 (0.3 mmol, 1.5 equiv), and a 1.0 M solution of LiHMDS in THF (20 μL; 10.0 mol%) were added to the solution and the tube was tightly capped, transferred out of the glovebox, and heated at 80 °C for 12 h. The mixture was then cooled, filtered through a short pad of silica gel (with elution by EtOAc), and concentrated under reduced pressure. The residue was purified by column chromatography.(3S)-1-(4-Methoxyphenyl)-3-propylpent-4-en-1-one (3aa)Synthesized from 1a and 2a by following the general procedure on a 0.2 mmol scale as a colorless viscous oil; yield: 44.1 mg, (96%; 95% ee, b/l = 15:1), [α]D 25 –14.0 (c = 0.8, CHCl3).HPLC [Shimadzu LC-2030; Chiralpak IG, i PrOH–hexane (1.0:99.0), 1.0 mL/min, 40 °C, λ = 254 nm]: t R = 22.660 min (major), 26.555 min (minor). 1H NMR (400 MHz, CDCl3): δ = 7.85 (d, J = 8.9 Hz, 2 H), 6.85 (d, J = 8.9 Hz, 2 H), 5.60 (ddd, J = 17.2, 10.3, 8.3 Hz, 1 H), 4.95–4.85 (m, 2 H), 3.79 (s, 3 H), 2.84 (d, J = 7.1 Hz, 2 H), 2.72–2.62 (m, 1 H), 1.38–1.19 (m, 4 H), 0.82 (t, J = 8.0 Hz, 3 H). 13C NMR (101 MHz, CDCl3): δ = 198.1, 163.4, 141.7, 130.5, 130.4, 114.6, 113.7, 55.4, 43.6, 39.8, 36.9, 20.2, 14.1. HRMS (ESI): m/z [M + H]+ calcd for C15H21O2: 233.1536; found: 233.1532.