Copper-Catalyzed Highly Regioselective Silylcupration of Terminal Alkynes to Form α-Vinylsilanes

A highly regioselective synthesis of branched vinylsilanes through silicon-copper additions to terminal alkynes catalyzed by copper(I) was developed using methanol as additive. The corresponding vinylsilanes were obtained with excellent branched to linear selectivity of up to 99/1 in good yields.