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 CH bond functionalization, catalyzed by the same catalytic system but under oxygen at 120 °C, afforded benzimidazoles 3 in good to excellent yields.