Copper-Catalyzed Defluorinative Thioannulation of Trifluoropropynes for the Synthesis of 1,2-Dithiole-3-thiones

A simple and practical strategy for the preparation of 1,2-dithiole-3-thiones via copper-catalyzed defluorinative thioannulation of trifluoropropynes has been developed using elemental sulfur as the sole sulfur source. This reaction displays a wide substrate scope and high functional group tolerance to afford the corresponding Sheterocycles in moderate to good yields and features efficient construction of multiple C-S bonds through C-F bond cleavage of CF3 groups.