Gold-Catalyzed Synthesis of Benzo[b]thiophenes from Alkynylphenylthiosilanes

Significance

Reported is the synthesis of 3-silylbenzo[b]thiophenes from (ortho-alkynylphenylthio)silanes under mild AuCl-catalyzed conditions in moderate to high yields. A mechanism involving a vinyl-Au intermediate was proposed for this process but the nature of the silyl migration is still unclear. Different solvents such as benzene, hexane, dichloromethane and ethyl acetate were also successfully used for this reaction. The scope and limitations for substrates were inadequately investigated.