Regioselective Monoarylation of 2-Phenylbenzimidazole via Ruthenium-Catalyzed­ C–H Bond Functionalization

Abstract The highly regioselective monoarylation of 1-methyl-2-phenyl-1 H -benzimidazole has been demonstrated. The reaction of 1-methyl-2-phenyl-1 H -benzimidazole with 4-iodoanisole provided 2-(4′-methoxybiphenyl-2-yl)-1-methyl-1 H -benzimidazole as the sole product in 96% isolated yield in the presence of [RuCl 2 ( p -cymene)] 2 and triphenylphosphine as precatalysts. A series of novel 2-(biphenyl-2-yl)benzimidazoles have been synthesized in good to excellent yields.