Cobalt-Tetraamide-Phthalocyanine Immobilized on Fe<sub>3</sub>O<sub>4</sub>/Chitosan Microspheres as an Efficient Catalyst for Baeyer–Villiger Oxidation
Zhilin Tang, Xiao Jin, Fei Li, Zhanhu Ma, Li Wang, Fanfan Niu, Sun Xiao
Abstract
Cobalt-Tetraamide-Phthalocyanine (CoTaPc) immobilized onto magnetic Fe3O4 chitosan microspheres (Fe3O4/CTO) was synthesized via a simple immersion method, which is an efficient catalyst for the oxidation of cyclic ketones to lactones with O2/benzaldehyde as the oxidant. The CoTaPc-Fe3O4/CTO catalyst was applied for the first time in the Baeyer–Villiger (B–V) oxidation reaction. Characterization results obtained from X-ray diffraction, UV–vis, Fourier transform infrared, and scanning electron microscopy showed that the combination of CoTaPc and magnetic Fe3O4/CTO microspheres was achieved. The catalyst could be easily separated from the reaction system with an external magnet and reused several times without the remarkable loss of activity. In addition, a possible radical mechanism for the B–V oxidation in this catalytic system is proposed and verified by controlled experiments.