Synthesis of Difluoroalkylated Benzofuran, Benzothiophene, and Indole Derivatives via Palladium-Catalyzed Cascade Difluoroalkylation and Arylation of 1,6-Enynes

Abstract

A novel and efficient method for the synthesis of difluoroalkylated benzofuran, benzothiophene, and indole derivatives via palladium-catalyzed aryldifluoroalkylation of 1,6-enynes with ethyl difluoroiodoacetate and arylboronic acids has been established. High reaction efficiency, mild conditions, broad substrate scope, and good functional group tolerance are the features of this protocol. Notablely, the resultant products can be smoothly converted into CF₂-containing benzofurans, benzothiophenes and indoles through an isomerization process catalyzed by Fe(OTf)₃.