Synthesis 2007(14): 2233-2235  
DOI: 10.1055/s-2007-966068
PSP
© 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 (eFirst)

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.

    References

  • 1a Harrowven DC. Pascoe DD. Demurtas D. Bourne HO. Angew. Chem. Int. Ed.  2005,  44:  1221 
  • 1b Banfi L. Basso A. Gandolfo V. Guanti G. Riva R. Tetrahedron Lett.  2004,  45:  4221 
  • 1c Mori K. Tetrahedron: Asymmetry  2005,  16:  685 
  • 1d Andrus MB. Meredith EL. Hicken EJ. Simmons BL. Glancey RR. Ma W. J. Org. Chem.  2003,  68:  8162 
  • 1e Abate A. Brenna E. Negri CD. Fuganti C. Serra S. Tetrahedron: Asymmetry  2002,  13:  899 
  • 2a De Bellefon C. Fouilloux P. Catal. Rev.  1994,  36:  459 
  • 2b Osborn ME. Pegues JF. Paquette LA. J. Org. Chem.  1980,  45:  168 
  • 3 Kim D. Park B.-M. Yun J. Chem. Commun.  2005,  1755 
  • 4 Lee D. Kim D. Yun J. Angew. Chem. Int. Ed.  2006,  45:  2785 
  • 5 (R)-(S)-Josiphos (R)-(S)-PPF-PCy2 = dicyclohexyl{(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl}phosphine. For a review, see: Blaser H.-U. Brieden W. Pugin B. Spindler F. Studer M. Togni A. Top. Catal.  2002,  19: 
  • 10 Its stereochemical assignment was made by comparison with the optical rotation of the corresponding ester derivative: Appella DH. Moritani Y. Shintani R. Ferreira EM. Buchwald SL. J. Am. Chem. Soc.  1999,  121:  9473 
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.