Fe3O4@Boehmite-NH2-CoII NPs: an inexpensive and highly efficient heterogeneous magnetic nanocatalyst for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions

Herein we report the synthesis of a magnetically separable core-shell-like Fe3O4@Boehmite-NH2-Co-II NPs as an environmentally friendly heterogeneous catalyst. The as-prepared nanocatalyst was well characterized by various techniques such as FT-IR, XRD, BET, TEM, FE-SEM, EDX, TGA, H-2-TPR, VSM, ICP-OES and elemental analysis and evaluated for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions in a green solvent (H2O). The results of characterization studies revealed the superparamagnetic behavior of the Fe3O4 NP core encapsulated by a Boehmite NP shell. Also, it was clearly found that the size of the particles was about 13-54 nm. In comparison with previously reported catalysts, Fe3O4@Boehmite-NH2-Co-II NPs exhibited perfect catalytic efficiency for the Suzuki-Miyaura and HeckMizoroki cross-coupling reactions under mild conditions without using toxic solvents. The concerted effects between individual components of the catalyst and also its unique egg-like nanostructure led to the high catalytic performance of Fe3O4@ Boehmite-NH2-Co-II NPs. Also, the introduction of Co significantly lowers the cost of the catalyst. More importantly, the longevity of the nanocatalyst was studied and it was found that the magnetic nanocatalyst was stable under the reaction conditions and could be easily reused for at least seven consecutive cycles without a discernible decrease in its catalytic activity or metal leaching.