Simple, Efficient, and Applicable Route for Synthesis of 2-Aryl(Heteroaryl)-Benzimidazoles at Room Temperature Using Copper Nanoparticles on Activated Carbon as a Reusable Heterogeneous Catalyst

A series of 2-(hetero)arylbenzimidazoles were synthesized by the catalytic condensation of (hetero)aryl aldehydes with 1,2-phenylenediamine derivatives at room temperature in the presence of air as the oxidant. Copper nanoparticles on charcoal was employed as an efficient and mild catalyst for this methodology.