Catalytic asymmetric hydrosilylation of olefins. : II. Chiral phosphine—nickel(II) and -rhodium(I) complex-catalyzed reaction

Abstract

Dichlorobis[( R)-benzylmethylphenylphosphine]nickel(II) was found to be a good catalyst precursor for the asymmetric hydrosilylation of 1,1-disubstituted prochiral olefins with methyldichlorosilane. The addition products were obtained in much higher optical yields than those obtained using chiral platinum(II) complexes. Trimethylsilane and phenyldimethylsilane were found to add readily to α-methylstyrene in the presence of chiral phosphine- rhodium complexes. Optical yields were not significantly affected by changes in structure of the hydrosilanes. Asymmetric induction was also observed in the nickel-catalyzed hydrosilylation of 1,4-cyclohexadiene. The stereochemical course of the asymmetric hydrosilylation of olefins is discussed.