Table 3.

CuBr₂/1_ox-catalyzed aerobic oxidative cross-coupling of benzylamine 2 a or aminomethylcyclopropane 2 n with o-aminoanilines 3^[a]

Entry	R2	R1	Benzimidazole Product4	Yield [%][c]
1	phenyl	methyl	4 t	81
2	phenyl	p-chlorophenyl	4 u	84[d]
3[b]	cyclopropyl	methyl	4 v	73[e]
4[b]	cyclopropyl	p-chlorophenyl	4 w	72[d,e]

[a] The reactions were carried out using equimolar amounts of primary amine 2 a (or 2 n) and o-aminoaniline 3 on a 1.25 mmol scale, in the presence of 4 mol % of 1_red and 0.4 mol % of CuBr₂, in 25 mL of MeOH, under ambient air for 24 h. After 6 h, an additional aliquot of 1_red (2 mol %) was added; [b] T=60 °C; [c] yield of isolated product; [d] yield after 48 h; [e] as volatile alkylamine 2 n was lost at 60 °C, an additional 0.5 equivalent of alkylamine was added after 6 h (entries 3 and 4) and after 24 h (entry 4).