Preparation of α-silyl- or α,α-bis(silyl)-substituted alkylcopper reagents and their synthetic use

Treatment of chlorobis(methyldiphenylsilyl)methyllithium with various alkyl and aryl Grignard reagents and CuCN·2LiCl afforded 1,1-disilylalkylcopper species. The aerobic oxidation of the resulting copper reagents provided a variety of acylsilanes in good yields. Meanwhile, treatment of dichloro(methyldiphenylsilyl)methyllithum with Bu2CuLi·LiCN provided 1-cyano-1-silylalkylcopper species via consecutive double 1,2-migration of alkyl and cyano groups.