The oxidative C–H amination of N″-aryl-N′-tosyl/N′-methylsulfonylamidines and N,N′-bis(aryl)amidines has been accomplished using iodobenzene as a catalyst to furnish 1,2-disubstituted benzimidazoles in the presence of mCPBA as a terminal oxidant at room temperature. The reaction is general, and the target products can be obtained in moderate to high yields.