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.