Effective Role of Two Layers of Silica in the Performance of Fe₃O₄@xSiO₂@ySiO₂@BisPyP-Ni Core-Shell Catalyst for C-C and C-S Coupling Reactions

In this research, a novel core-shell nanocatalyst with silica bi-shell around Fe₃O₄ and nickel active center, i.e. Fe₃O₄@xSiO₂@ySiO₂@BisPyP-Ni was synthesized and its characteristics were comprehensively discussed. This nanocatalyst was successfully used to synthesize biaryls (18 examples, 15–30 min, 92–98%) and diaryl sulfides (10 examples, 20–140 min, 79–98%) at 80 °C. Excellent performance in speeding up the reaction time, magnetic nature, high porosity, and immobilization of two layers around Fe₃O₄ are four prominent characteristics of this catalyst. Coating the magnetic core with silica layers led to saving the consumption of the catalyst because this trick leads to the bonding of more organic groups to the substrate, as a result, more nickel enters the mesoporous cavities, and the reaction with a smaller amount of catalyst is finished (in a shorter time). Other advantages of both our production lines are: the ability to recover and reuse the catalyst for up to 8 runs (without a noticeable decrease in its catalytic performance), extensive substrate scope, the employ of commercially accessible materials, simple workup, environmental safety and the heterogeneous nature of the catalyst (by confirming the reusability and hot filtration test results).