Selective oxidation of alcohols with hydrogen peroxide in the presence of novel and reusable catalyst of nickel-isatin Schiff base complex immobilized into MCM-41

In this research, firstly, MCM-41 mesoporous was synthesized and amino-modified by 3-aminopropyltriethoxysilane (3-APTES), and subsequently by adding of isatin, imine-functionalized MCM-41 was obtained. Then by adding of NiCl2.6H2O salt to the imine-functionalized MCM-41, the Ni-isatin Schiff base complex anchored into MCM-41 was prepared as a novel and heterogeneous catalyst. The synthesized catalyst was characterized by ICP, FT-IR, XRD, SEM, BET and TGA techniques. The prepared catalyst was used for selective oxidation of primary and secondary alcohols with hydrogen peroxide 30%. In this catalytic system, the effect of different parameters such as solvent, temperature, catalyst amount, and kind of oxidant was studied and according to the obtained results, acetonitrile and hydrogen peroxide 30% were selected as the best solvent and oxidant, respectively. Also, the results showed that in this catalytic system, the primary and secondary alcohols were converted to corresponding aldehydes and ketones with high selectivity and yield of 73-90%. Furthermore, the prepared catalyst can be recovered and reused four times without significant loss of its catalytic activity.