Visible Light-Induced Highly Regioselective and Stereoselective Oxysulfonylation of Alkynes for the Synthesis of ( E )-β-Phenoxy Vinylsulfones.

A highly efficient visible light-induced regioselective and stereoselective oxysulfonylation of alkynes with arylsulfonate phenol esters has been developed. This photocatalyst- and metal-free method proceeds smoothly under very mild conditions and exhibits a broad substrate scope, providing ( E )-β-phenoxy vinylsulfones in moderate to excellent yields. Mechanistic studies indicated the involvement of an electron donor-acceptor complex-mediated radical process.