Brønsted acid-catalyzed regioselective ring opening of 2 H -azirines by 2-mercaptopyridines and related heterocycles; one pot access to imidazo[1,2- a ]pyridines and imidazo[2,1- b ]thiazoles

A TfOH-catalysed ring opening of 2 H -azirines by 2-mercaptopyridines and thiazole-2-thiols is reported to access imidazo[1,2- a ]pyridines and imidazo[2,1- b ]thiazoles in one pot.