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Synthesis 2007(14): 2233-2235  
DOI: 10.1055/s-2007-966068
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© Georg Thieme Verlag Stuttgart · New York

Copper Hydride Catalyzed Enantioselective Conjugate Reduction of Unsaturated Nitriles

Daehyung Lee, Youngmin Yang, Jaesook Yun*
Department of Chemistry and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Korea
Fax: +82(31)2907075; e-Mail: jaesook@skku.edu;
Further Information

Publication History

Received 14 February 2007
Publication Date:
11 May 2007 (online)

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Abstract

α,β-Unsaturated nitriles were reduced with high levels of enantioselectivity via copper hydride catalysis. In this procedure, bench-top stable copper(II) acetate and Josiphos ligand are used as the chiral catalyst and an inexpensive hydrosilane, polymethylhydrosiloxane (PMHS) is employed as the stoichiometric reducing agent. While the reactions are conducted at 0 °C in most cases, they also can be conducted at room temperature at enhanced rates with no significant drop in enantiomeric excess.

Key words

asymmetric catalysis - copper hydride - hydrosilanes - reduction - α,β-unsaturated nitriles

    References

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6

BINAP = 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene.

7

p-Tol-BINAP = 2,2′-bis(di-4-tolylphosphino)-1,1′-bi­-naphthalene.

8

(R)-(S)-PPF-Pt-Bu2 = di-tert-butyl{(R)-1-[(S)-2-(diphenyl-phosphino)ferrocenyl]ethyl}phosphine.

9

(R)-(S)-Cy2PF-PCy2 = dicyclohexyl{(R)-1-[(S)-2-(dicyclo-hexylphosphino)ferrocenyl]ethyl}phosphine.