Substrate specificity in the biomimetic catalytic aerobic oxidation of styrene and cyclohexanone by metalloporphyrins: kinetics and mechanistic study  

作　　者：Xian-Tai Zhou Hong-Bing Ji 

机构地区：[1]Fine Chemical Industry Research Institute,Sun Yat-sen University,Guangzhou,510275,China [2]School of Chemical Engineering,Guangdong University of Petrochemical Technology,Maoming,525000,China

出　　处：《Green Chemical Engineering》2021年第2期217-223,共7页绿色化学工程（英文）

基　　金：support from the National Natural Science Foundation of China(No.21938001 and 21878344);the National Key Research and Development Program of China(2016YFA0602900);the National Natural Science Foundation of ChinaSINOPEC Joint Fund(No.U1663220);Guangdong Provincial Key R&D Programme(2019B110206002);the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01C102);Research and Innovation Team Construction Project of Guangdong University of Petrochemical Technology.

摘　　要：Substrate specificity is a hallmark of enzymatic catalysis.In this work,the biomimetic catalytic oxidation of styrene and cyclohexanone by iron(III)porphyrins and molecular oxygen was carried out,and remarkable differences in efficiency were observed.The specificity of the substrates for biomimetic catalytic oxidation was investigated by kinetics and mechanistic studies.Kinetics studies revealed that the oxidation of styrene followed Michaelis-Menten kinetics with KM=8.99 mol L^(-1),but the oxidation of cyclohexanone followed first-order kinetics with kobs=1.46×10^(-4) s^(-1),indicating that the styrene epoxidation by metalloporphyrins exhibited characteristics of enzyme-like catalysis,while the oxidation of cyclohexanone was in agreement with the general rules of chemical catalysis.Different catalytic mechanisms for the two substrates were discussed by operando electron paramagnetic resonance spectroscopy,operando UV-vis spectroscopy,and KI/starch experiments.Substrate specificity was concluded to be attributed to the stability of high-valence species and oxygen transfer rate.

关 键 词：Substrate specificity KINETICS Oxidation METALLOPORPHYRINS Mechanism 

分 类 号：O621.251[理学—有机化学]