Ethylenediamine-functionalized magnetic Fe 3 O 4 @SiO 2 nanoparticles: cooperative trifunctional catalysis for selective synthesis of nitroalkenes

A magnetically separable trifunctional nanocatalyst Fe 3 O 4 @SiO 2 –NH 2 was synthesized and characterized by TEM, FT-IR, XRD, TGA, and EA. The designed nanocatalyst was found to be highly active for selective synthesis of nitroalkenes with nitromethane and aromatic aldehyde through cooperative trifunctional catalysis of primary amine, secondary amine and Si–OH groups on the surface of the catalyst. Under the optimized conditions, various representative substrates were extended to obtain the corresponding products in moderate or excellent yields. After the reaction, the trifunctional nanocatalyst was easily recovered and recycled by applying an external magnet. In addition, a possible cooperative trifunctional catalysis mechanism was also proposed.