First synthesis of (difluoroiodomethyl)thiophenes through double iodation of 2-(difluoromethylene)but-3-yn-1-yl benzyl sulfides

Abstract

The Sonogashira cross-coupling of 2-bromo-3,3-difluoroallyl benzyl sulfide with various terminal acetylenes afforded the corresponding 2-(difluoromethylene)but-3-yn-1-yl benzyl sulfides in acceptable to good yields. Subsequent double iodation of the enyne sulfides in a mixed solvent (CHCl₃/EtOH = 50/1) provided promising 4-(difluoroiodomethyl)-3-iodo-2-substituted thiophenes in good to excellent yields.