Copper and Iron-assisted Palladium-catalyzed Direct Arylation of Azoles with Arylboronic Acids under Ligand and Base-free Conditions

The direct arylation of azoles with arylboronic acids is effectively promoted by PdCl2 in the presence of copper and iron salts under ligand and base-free conditions. This reaction can be applied to heterocycles such as benzothiazole, benzoxazole, 1-methylbenzimidazole and 4,5-dimethylthiazole with moderate to good yields.