A novel, efficient and magnetically recyclable Cu–Ni bimetallic alloy nanoparticle as a highly active bifunctional catalyst for Pd-free Sonogashira and C–N cross-coupling reactions: a combined theoretical and experimental study

Abstract

In this study, a Fe₃O₄@SiO₂@Cyt-Ni/Cu nanocomposite as a novel heterogeneous bimetallic catalyst was synthesized which exhibits efficient performance for the Sonogashira and C–N cross-coupling reactions. The characterization of the catalyst was studied by FT-IR, PXRD, VSM, EDX, TEM, FE-SEM and TGA analyses. The geometry optimization and relative energies of the designed bimetallic complexes were theoretically determined using density functional theory (DFT) calculation at the B3LYP/6-31G**/LANL2DZ level. The catalyst showed good activity in the coupling of various aryl halides with alkynes (Sonogashira reaction) as well as aryl halide with N-heterocycles and achieved coupling products with good to high yields for all of them in a short time. The high catalytic performance could be due to the synergistic effect between Ni and Cu, which causes the reaction to proceed more efficiently. This heterogeneous nanocatalyst could be easily recovered from the reaction mixture with an external magnet and reused for 7 consecutive runs with minimal loss of catalytic activity.