Super-paramagnetic polymer composite-supported dendrimer–Mn catalyst: Fabrication, characterization and catalytic evaluation in selective aerobic oxidation of ethylbenzene and oximes derivatives

Design of strategy and catalytic for oxidation ethylbenzene, toxic petroleum, to high value-added via hydrogen-atom-transfer process is lately attracting a renewed interest from both environmentally and economic view. Herein, novel manganese-based dendritic catalysts supported on the polymer-magnetic core-shell were synthesized, fully identified and evaluated with initiator NDHPI for selective and easy-to-handle aerobic oxidation of ethylbenzene (EB) and oximes to acetophenone (ACP) & carbonyl compounds (AH/KO), respectively. Besides mild condition reaction, the supported dendrimer-encapsulated Mn NPs also exhibited outstanding catalytic performance, such as selective oxidation of ethylbenzene and oximes using O2 as green and cheaper oxidant with excellent reactivity, selectivity, stability, and magnetic recyclability. Additionally, the effect of operating parameters such as the amount of catalyst, nature of solvent, temperature and reaction time, and role of several N-hydroxyimides were studied in the catalytic efficiency of the synthesized dendritic catalyst. The results illustrated that the enhanced catalytic efficiency of the catalyst is derived from the magnetic dendritic structures, high Mn(II) content, hydrophobic arm of dendrimers, and interaction of Mn and the dendritic framework. Finally, the reaction pathway for EB and oxime has been deduced, and the crucial role of dendritic catalyst, NDPHI, and electronic effect has been elucidated. •Mn(II)@G2.0–3.0-Polymer(4-VT/VS/GMA)-MBNP were fabricated by divergent and co-polymerization methods and fully characterized.•The catalysts were highly efficient and selective for aerobic oxidation of ethylbenzene and oxime derivatives.•Effect of structural and operating factors on efficiency of process, superparamagnetic behaviors and radical pathway were elucidated in detail.