Stereoselective Synthesis of Polyfunctional Tetrasubstituted Alkenyl Sulfides via a Carbocupration of Alkynyl Sulfides with Aryl and Benzylic Diorganozincs

A general method for the synthesis of tetrasubstituted alkenyl sulfides has been developed by the carbocupration of alkynyl sulfides with functionalized diorganozinc reagents in the presence of CuCN center dot 2LiCl. The intermediate alkenylcopper reagents readily react with various electrophiles furnishing a broad range of highly functionalized alkenes with excellent stereoselectivity (E/Z 93:7-99:1).