Divergent Reaction of Alkynes and TsCN: Synthesis of β-Sulfinyl Alkenylsulfones and ()-Vinyl Sulfones.

An efficient and high-selectivity approach for the divergent synthesis of β-sulfinyl alkenylsulfones and ()-vinyl sulfones from alkynes and TsCN is described. A series of disulfurized products were constructed under mild conditions in the absence of transition metals. This transformation featured excellent regio- and stereoselectivity, good functional group compatibility, and broad substrate scope. The copper(I)-catalyzed sulfonation of alkynes with TsCN that affords ()-vinyl sulfones in good to excellent yields was also developed.