Schiff base functionalized Fe3O4@Boehmite Core-Shell Nano-Particles to Support MoO2(acac)2 for Catalytic Epoxidation of Alkenes

Fe3O4 nanoparticles were prepared solvothermally and then covered with boehmite shell via hydrothermal assisted sol-gel processing of aluminum 2-propoxide. Then the hydroxyl covered outer surface of the boehmite shell was covalently functionalized with 3-(tri-methoxysilyl) propylamine and the terminal amine groups converted to imine by refluxing with 2-hydroxybenzaldehyde. Then it was used to support bis-acetylacetonato-di-oxo-molybdenum (VI). The supported catalyst was characterized by Fourier transform Infrared spectroscopy, elemental analysis, inductive coupled plasma and transmission electron microscopy analysis and it was applied in the epoxidation of cis-cyclooctene. The catalytic procedure was optimized for different parameters such as solvent, oxidant, and temperature. The reaction progress was investigated by gas-liquid chromatography analysis. The used catalyst was simply recovered from the solution by applying a magnet and recycling experiments revealed that this heterogeneous nano-catalyst could be repeatedly applied for the epoxidation of cis-cyclooctene. The optimized conditions were also used for the epoxidation of some other alkenes successfully.