Synthesis of nitriles by the electro-oxidative coupling of primary alcohols and ammonia on Pd nanoparticle-modified CuO nanowires in oxidant-free electrolytes under ambient conditions

Developing green strategies for the synthesis of nitriles from cheap starting materials, without toxic and hazardous reagents under mild conditions is important for the sustainable development of the chemical industry. Herein, we report an oxidant- and cyanide-free catalytic system for the synthesis of various nitriles via electro-oxidative coupling of corresponding primary alcohol and ammonia in an aqueous solution with Pd nanoparticle-modified CuO nanowires as the catalyst. Produce benzonitrile from benzyl alcohol achieve a conversion of > 99.0 % and a selectivity of 83.2 %. Mechanism studies demonstrate that the coupling of surface-adsorbed active species NH2 * and Ph-CHO* is the rate-limiting step, and the Pd/CuO heterojunction is the active center. The electrogenerated CuIII species provide the driving force for oxidation, and Pd contributes to improving the dehydrogen ability and facilitating the subsequent coupling reaction. Our research provides an environment-friendly oxidative C-N coupling method for efficient nitriles electrosynthesis.