A copper-catalyzed multi-component reaction accessing fused imidazo-heterocycles via C–H functionalization

Abstract

An efficient synthesis of fused imidazo-heterocycles is described using Cu(OTf)₂ in [bmim]BF₄ by the multi-component reaction of pyridin-2(1H)-one or thiazol/benzo[d]thiazol-2(3H)-ones with O-tosylhydroxyl amine and acetophenones under microwave irradiation. The present method is very rapid and the product formation occurs via a C–H functionalization/tandem addition-cyclization process. The ionic liquid containing copper triflate is recovered and reused four times.