Aerobic Copper-Catalyzed Synthesis of Benzimidazoles from Diaryl- and Alkylamines via Tandem Triple C–H Aminations

Through radical-induced tandem triple C–H aminations with free amines as the aminating agents, we herein present a precedent on aerobic copper-catalyzed synthesis of 5-diarylamino benzimidazoles, a class of optoelectronic device analogues by combining two molecules of diarylamines and one molecule of alkylamine in one single operation. The developed chemistry proceeds with the merits of a natural abundant copper/O2 catalyst system, readily available feedstocks, broad substrate scope, good functional group tolerance, exclusive regio- and chemoselectivity, high step and atom efficiency, which offers an important basis for further construction of functional products that are inaccessible or difficult to prepare with the existing methods by employing catalytic tandem C–H amination strategy.