Asymmetric protonation of silyl enolates catalyzed by chiral phosphine-silver(I) complexes

Abstract

A catalytic asymmetric protonation of trimethylsilyl enolates was achieved using a 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP)-silver(I) fluoride complex as a chiral catalyst in a mixed solvent consisting of dichloromethane and methanol. Various nonracemic ketones possessing a tertiary asymmetric carbon at the α-position were prepared with high enantioselectivity up to 99% ee. © 2006 IUPAC.