Copper-catalyzed one-pot synthesis of 2-(2,2,2-trifluoroethyl)-substituted benzofused heterocycles

Abstract

A novel synthesis approach for the construction of 2-trifluoroethyl-substituted benzofurans under copper-catalyzed conditions has been developed. The reaction of salicylaldehyde p-tosylhydrazones with 2-bromo-3,3,3-trifluoropropene proceeded through a sequential process to afford products in moderate to excellent yields (up to 93%). This method is also applicable to the formation of 2-trifluoroethylated indoles.