Cu(I)-Catalyzed Radical Coupling of Alkenes with Sulfonimidoyl Chlorides: Synthesis of Vinyl Sulfoximines.

A Cu(I)-catalyzed radical coupling was reported for the synthesis of vinyl sulfoximines from sulfonimidoyl chlorides and alkenes under mild, light-free conditions. This method proceeds via a sulfonimidoyl radical intermediate, generated through Cu(I) reduction, and demonstrates broad substrate tolerance, delivering products in up to 84% yield. The transformation could also be efficiently conducted in a practical one-pot manner by generating the sulfonimidoyl chloride in situ from the S(IV) sulfonamide. Moreover, the addition of tBuOCl further improved the yields of vinyl sulfoximines for several substrates. Mechanistic studies support a radical pathway involving this key sulfonimidoyl radical species.