Construction of Fe₃O₄@BTH-Pyr-CuCl nanocomposite as a highly active magnetically reusable catalyst for arylation of a category of heterocycles

C–H arylation of heterocyclic compounds is a very interesting and important research field in chemistry for the formation of C–C bonds, but unfortunately, few methods have been reported for this purpose. In this attractive and highly efficient methodology, we wish to report that copper (I) chloride immobilized on magnetic nanoparticles modified with benzothiazole-pyrimidine Ligand (Fe₃O₄@BTH-Pyr-CuCl) is a novel and efficient magnetically recoverable catalyst for carbon–carbon bond formation through C–H arylation of a category of heterocyclic compounds by aryl iodides in the presence of KOAc in PEG under mild conditions. Under this catalytic system, A category of heterocyclic substrates including benzo[d]oxazole, benzo[d]thiazole, 1-methyl-1H-benzo[d]imidazole, 2,5-diphenyloxazole, benzofuran, 2-phenyl-1,3,4-oxadiazole and 2-phenylimidazo[1,2-a]pyridine were used as substrate and the desired products were prepared with high to excellent yields. Reusability tests revealed that the Fe₃O₄@BTH-Pyr-CuCl catalyst can be reused at least 7 runs without significant decrease in its catalytic efficiency. ICP-OES, VSM and SEM techniques confirmed the recovered Fe₃O₄@BTH-Pyr-CuCl catalyst was very stable and had high magnetic property despite the utilization for 7 runs.