Palladium- and copper-mediated direct C-2 arylation of azoles - Including free (NH)-imidazole, -benzimidazole and -indole - Under base-free and ligandless conditions

The first palladium- and copper-mediated C-2 arylations of thiazole, oxazole, N-methylimidazole and N-arylimidazoles, as well as of free (NH)-imidazole, -benzimidazole and -indole, with aryl iodides under ligandless and base-free conditions are described. Complete selectivity has been achieved under these unprecedented conditions, which allow the use of substrates containing base-sensitive groups, such the NH groups of imidazole, benzimidazole or indole, without their prior protection. No N-arylation products were detected in the arylation of free (NH)-imidazole, -benzimidazole and indole. (c) Wiley-VCH Verlag GmbH & Co