The chemoselective and complementary Pd- and Cu-catalyzed N-arylation of 2-aminobenzimidazoles is described. Selective N-arylation of the amino group was achieved with a Pd-catalyzed method, while selective N-arylation of azole nitrogen was achieved with a Cu-catalyzed procedure.
“Catalyst-controlled chemoselective arylation of 2-aminobenzimidazoles”, Angew. Chem., Int. Ed., 2012, 51(41), 10364-7.