N,N‐Dimethylformamide as a Methylenating Reagent: Synthesis of Heterodiarylmethanes via Copper‐Catalyzed Coupling between Imidazo[1,2‐a]pyridines and Indoles/N,N‐Dimethylaniline

A new copper-catalyzed, efficient method for the synthesis of heterodiarylmethanes through the coupling of imidazo[1,2-a]pyridines with indoles employing N,N-dimethylformamide as a methylenating reagent has been developed. A library of 3-(1H-indol-3-ylmethyl)-imidazo[1,2-a]pyridine derivatives has been synthesized under aerobic reaction conditions. This protocol is also applicable for the synthesis of (4-imidazo[1,2-a]pyridin-3-ylmethyl)(phenyl)dimethylamines. The method is highly selective for the hetero-coupling.