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