Sustainable fabrication of NiCuFe2O4 nanospheres: a highly effective palladium-free heterogeneous catalyst for biaryl scaffold synthesis via a Suzuki-Miyaura cross-coupling reaction

In this work, a noble metal-free and recyclable NiCuFe2O4 nanoparticle was developed via a one-pot co-precipitation approach. The synthesized nanoparticle was characterized by various sophisticated techniques such as SEM, EDX, VSM, PXRD, XPS, BET, ICP-AES, ICP-MS, elemental mapping and TEM analyses to gain detailed insights about its physiochemical properties. Electron microscopy studies validate the formation of hierarchical nanosphere morphology of the as-synthesized NiCuFe2O4 nanoparticles, while VSM analysis highlights their ferromagnetic nature. Powder X-ray diffraction reveals that Cu replaces Ni in the face-centered cubic lattice, causing a shift in peak positions as well as an increase in the lattice parameter with reduced Ni content. This cost-effective and magnetically separable NiCuFe2O4 nanostructure holds promise as a potential substitute for Pd-based catalysts in Suzuki-Miyaura cross-coupling of arylboronic acid with various substituents of aryl halide. Notably, they demonstrate remarkable catalytic activity in producing biaryl scaffolds by effectively activating not only Ar-Br bonds but also chemically inert Ar-Cl and Ar-F bonds under mild conditions in ethanol-water media, outperforming most of the reported works involving transition metal-based catalysts. These heterogenous catalysts have the tendency to retain their activity up to the fifth iterations during the reaction with a broad substrate scope, providing significant economic advantages for industrial applications.