Copper-Catalyzed Dehydrogenative C(sp2)-N Bond Formation via Direct Oxidative Activation of an Anilidic N-H Bond: Synthesis of Benzoimidazo[1,2-a]indoles.

Abstract

A dehydrogenative C(sp2)-N bond-forming strategy via copper-catalyzed intramolecular C-H/N-H coupling has been developed, which systematically unraveled the feasibility and practicality for benzoimdazo[1,2-a]indole formations through oxidative anilidic N-H activation. The merit of this strategy is illustrated by the broad tolerance of functionalities, as well as the utilization of extremely cheap copper catalysis to realize potentially useful indole-fused tetracycles in a step- and atom-economical manner.