Aerobic intermolecular cross dehydrogenative coupling reaction using CuO-NiO-TiO2 trimetallic nanocomposite: A remarkable version of synergistic catalysis

Abstract

Activation of the proelectrophilic Csp3-H bond of fused tetrahydropyridines is achieved by the catalyst system of CuO-NiO-TiO2 trimetallic nanocomposite, enabling regioselective cross-dehydrogenative coupling of pronucleophilic Csp3-H and Csp2-H substrates, resulting in single Csp3-Csp3/Csp3-Csp2 bond formation.The synergistic activity of the trimetallic composite was evidenced by studying the corresponding bimetallic oxide systems (CuO-TiO2, NiO-TiO2). A broad-spectrum of N-aryl tetrahydroisoquinoline proxies and various nucleophiles of different CH bonds (Csp3-H, Csp2-H) are cross-coupled efficiently in aerobic, neat heating conditions consistent with Green chemistry principles.