Catalyst-controlled chemoselective arylation of 2-aminobenzimidazoles.

The chemoselective and complementary Pd-and Cu-catalyzed N-arylation of 2aminobenzimidazoles 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 Cucatalyzed procedure. The utility of these complementary sets of conditions is demonstrated in several two-step, selective syntheses of di-arylated aminoazoles.