Copper Catalyzed N-Arylation of Amidines with Aryl Boronic Acids and One-Pot Synthesis of Benzimidazoles by a Chan-Lam-Evans N-Arylation and C-H Activation/C-N Bond Forming Process

Mono-N-arylation of benzamidines 1 with aryl boronic acids 2 was effectively achieved in the presence of a catalytic amount of Cu(OAc)(2) and NaOPiv under mild aerobic conditions. Combining this step with an intramolecular direct C-H bond functionalization, catalyzed by the same catalytic system but under oxygen at 120 degrees C, afforded benzimidazoles 3 in good to excellent yields.