Selective C–H trifluoromethylation of benzimidazoles through photoredox catalysis

Abstract

The protocol presented here is a new strategy for visible light induced C–H trifluoromethylation at C₄ of benzimidazoles using Togni's reagent in the presence of fac-Ir(ppy)₃. Its advantages are its operational simplicity, mild reaction conditions, low catalyst loading and wide substrate scope in which electron-withdrawing, electron-donating groups and different protecting groups are tolerated.