Nano copper oxide mediated ligand-free C–S cross-coupling and concomitant oxidative aromatization of 4-aryl-3,4-dihydropyrimidin-2(1H)-thione with diaryliodonium salts

A wide range of Biginelli 4-aryl-3,4-dihydropyrimidin-2(1H)-thiones undergo ligand-free C–S cross-coupling with diaryliodonium triflates in the presence of CuO nanoparticles with the concomitant oxidative aromatization to form highly substituted 2-(thioaryl)pyrimidine. The nano CuO catalyst can be recycled and reused three times without any significant loss of catalytic activity.