A copper-catalyzed cascade reaction of o-bromoarylisothiocyanates with isocyanides leading to benzo[d]imidazo[5,1-b]thiazoles under ligand-free conditions

A convenient and efficient copper-catalyzed domino method has been initially developed for the synthesis of benzo[d]imidazo[5,1-b]thiazole derivatives via the reactions of readily available substituted o-bromoarylisothiocyanates with isocyanides under ligand-free conditions. This chemistry involves intermolecular [3 + 2] cycloaddition and intramolecular Ullmann-type C-S bond formation.