Sustainable ruthenium-catalyzed C–H alkylation of 2-(hetero)aryl benzimidazoles with maleimides

Abstract

An efficient protocol for the ruthenium-catalyzed C–H alkylation of 2-(hetero)aryl benzimidazoles with maleimides is reported. Key features include the use of an inexpensive, bench-stable [RuCl₂(p-cymene)]₂ precatalyst in the green solvent 2-MeTHF under air, without stoichiometric metal additives. This work establishes the benzimidazol-2-yl group as a competent directing group and offers a practical, sustainable route to valuable heterocyclic scaffolds.