Copper-Catalyzed Trifluoromethylthio-arylsulfonylation of Styrene Derivatives via the Insertion of Sulfur Dioxide

A copper-catalyzed four-component trifluoromethylthio-arylsulfonylation between styrene derivatives, AgSCF3, aryldiazonium tetrafluoroborates, and ex situ generated sulfur dioxide (from SOgen) is presented. This reaction features mild reaction conditions, good functional group tolerance, a broad substrate scope, good yields, and excellent diastereoselectivity. Preliminary mechanistic studies revealed that a radical process might be involved in this transformation.