Palladium-Catalyzed Tandem Synthesis of 2‑Trifluoromethylthio(seleno)-Substituted Benzofused Heterocycles

The tandem synthesis of 2-trifluoromethylthio­(seleno)-substituted benzofurans using palladium-catalyzed conditions is reported. Trifluoromethylthio­(seleno)­lation of 2-(2,2-dibromovinyl)­phenols with (bpy)­CuSCF₃ or [(bpy)­CuSeCF₃]₂ furnishes several 2-trifluoromethylthio­(seleno)­lated benzofurans in acceptable to good yield. Mechanistic investigations were performed to elucidate the reaction pathway, which was involved in the formation of a 2-bromobenzofuran species. The scope of this protocol was further extended to the preparation of 2-trifluoromethylthio­(seleno)­lated benzothiophenes and indoles.