Assembly of substituted 1H-benzimidazoles and 1,3-dihydrobenzimidazol-2-ones via CuI/L-proline catalyzed coupling of aqueous ammonia with 2-iodoacetanilides and 2-iodophenylcarbamates.

CuI/l-proline catalyzed coupling of aqueous ammonia with 2-iodoacetanilides and 2-iodophenylcarbamates affords the aryl amination products at room temperature, which undergo in situ additive cyclization under acidic conditions or heating to give substituted 1H-benzimidazoles and 1,3-dihydrobenzimidazol-2-ones, respectively. A wide range of functional groups including ketone, nitro, iodo, bromo, and ester are tolerated under these reaction conditions, providing these heterocycles with great diversity.