Synthesis of 1-Substituted Benzimidazoles from o-Bromophenyl Isocyanide and Amines

o-Bromophenyl isocyanide (1-Br) reacts with various primary amines under Cu-I catalysis to afford 1-substituted benzimidazoles 4 in moderate to good yields (38-70%, 13 examples). Analogously, 2-bromo-3-isocyanothiophene (6) furnishes 3-substituted 3H-thieno[2,3-d]imidazoles 7 (44-49%, 3 examples). ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)