Electrochemical Synthesis of Imidazo-Fused N-Heteroaromatic Compounds through a C-N Bond-Forming Radical Cascade.

We have developed a unified strategy for preparing a variety of imidazo-fused N-heteroaromatic compounds through regiospecific electrochemical (3+2) annulation reaction of heteroarylamines with tethered internal alkynes. The electrosynthesis employs a novel tetraarylhydrazine as the catalyst, has a broad substrate scope, and obviates the need for transition-metal catalysts and oxidizing reagents.