“…This promised to be a trivial exercise due to the related chemistry of its N-phenyl congener that we had recently reported. [14] However, applying the conditions that had previously proven most effective (6 mol-% 1 red precursor of 1 ox , 0.4 mol-% CuBr 2 , MeOH, 45°C, air), the oxidative condensation of N-methyl-o-aminoaniline (3a) with a range of primary amines 2 was not selective, affording, in addition to the desired 1,2-disubstituted benzimidazole product 4, N-methylbenzimidazole (5a) as a minor product. Its formation, in an isolated yield of up to 28 %, was favored when the rate of the main reaction was affected either by steric effects in the case of benzylic amines (Table 1, entry 7) or by the decreased reactivity of the -branched alkylamines (Table 1, entries 17 and 18).…”