Study on the Bimetallic Synergistic Effect of Cu/Al@SBA-15 Nanocomposite on Dehydrogenation Coupling Strategy

Dehydrogenation coupling reaction is an efficient strategy of metal-catalyzed organic synthesis, but it is still a research hotspot to regulate the positive effect of various metals on the reaction and make them cooperate with each other. In this work, nanocomposite modified with aluminum and loaded with copper were used as bimetallic catalysts for dehydrogenation coupling reaction. The results showed that the modification of aluminum maked CuO particles disperse highly and exist stably on SBA-15. The bimetallic synergistic catalytic effect of Cu/Al@SBA-15 composite was far greater than that of any one active components alone, and the synergistic effect between Cu and Al was the main reason for its excellent catalytic performance. It guided the dehydrogenation coupling reaction of o-aminophenol and benzyl alcohol, and a series of benzothiazoles products were obtained efficiently by one-pot method. Moreover, the Cu/Al@SBA-15 catalyst still has stable catalytic activity after repeated use, and the leaching of aluminum and copper species in solution was negligible after the reaction. The copper–aluminum bimetal used in strategy does not belong to the highly toxic metal sequence, so this method provides a green synthesis platform for accessing pharmaceutically relevant benzoazoles. Graphical abstract: [Figure not available: see fulltext.] General Scheme. Synthesis of o-aminophenols and benzyl alcohols to benzothiazoles catalyzed by bimetallic synergistic effect of Cu/Al@SBA-15 nanocomposite.