CuPd bimetallic nanoparticles supported magnetic ionic liquid-derived N-doped carbon as a highly efficient heterogeneous catalyst for the one-pot oxidative multicomponent reactions

Abstract

BackgroundMulticomponent reactions often rely on aldehydes as the reactants, limiting their widespread use. To enhance the versatility and scope of these reactions, aldehydes can be replaced with alcohols. MethodsIn this study, nitrogen-doped magnetic carbon nanostructures modified with imidazolium-based ionic liquid (Fe3O4@NC-IL) were prepared. These nanostructures were synthesized by a one-pot hydrothermal carbonization method using ferric chloride in the presence of glucose, urea, epichlorohydrin and 1-methylimidazole as carbon source, nitrogen source, linker and ionic liquid, respectively. Then, CuPd bimetallic nanoparticles were immobilized on the synthesized nanostructures by a wet chemical reduction process. Significant findingsThe catalytic activity of the nanostructures was evaluated in the oxidation of alcohol under base-free conditions. The results indicate that the CuPd bimetallic catalyst exhibited better catalytic performance than both Cu and Pd monometallic catalysts, suggesting a synergistic effect between copper and palladium. Also, a non-ionic liquid-based catalyst was synthesized and used in the model reaction to study the effect of imidazolium ionic liquid species on the catalytic activity. The results showed that these species enhanced the catalytic activity. Finally, the catalytic activity of the synthesized structure was evaluated through a one-pot tandem oxidative synthesis of dihydropyrimidinones (Biginelli reaction) and dihydropyridines (Hantzsch reaction).