The silylcupration of acetylenes: a synthesis of vinylsilanes

Abstract

Bis(dimethylphenylsilyl)copper-lithium (1) reacts with hex-1-yne, propyne, acetylene itself, phenylacetylene, and hex-3-yne to give the products of syn addition of the dimethylphenylsilyl group and the copper. The resultant vinylcopper reagents react with a variety of electrophiles, such as the proton, iodine, acyl and alkyl halides, enones, and epoxides, to give vinylsilanes. With the terminal alkynes, the silyl group becomes attached with a high level of regioselectivity to the terminal carbon atom, with the result that the final products are 2,2-disubstituted vinylsilanes.