Synthesis of ( E)-β-Selenovinyl Sulfones through a Multicomponent Regio- and Stereospecific Selenosulfonation of Alkynes with Insertion of Sulfur Dioxide.

A novel and practical method for the selenosulfonation of alkynes with the insertion of sulfur dioxide has been developed. A series of β-(seleno)vinyl sulfones with high levels of regio- and stereoselectivity have been prepared. The key features of this reaction include a broad substrate scope, excellent functional-group tolerance, and amenability to scale-up synthesis. A plausible radical mechanism is proposed to illustrate this reaction.