Experimental and theoretical study on N-hydroxyphthalimide and its derivatives catalyzed aerobic oxidation of cyclohexylbenzene

The liquid phase oxidation of cyclohexylbenzene(CHB)is a new green synthetic approach to cyclohexylbenzene-1-hydroperoxide(CHBHP),a key intermediate for preparing phenol and cyclohexanone.In this work,aryl-substituted(Cl and Br)derivatives of N-hydroxyphthalimide(NHPI)were synthesized and their catalytic performances for CHB oxidation were studied.In addition,geometric optimization and transition state search were performed using DFT calculations.Both experimental and theoretical studies have proven that chloro-substitution on NHPI can significantly improve its catalytic effects on the oxidation of CHB by oxygen.Compared with NHPI,CHB conversion and selectivity of CHBHP over Cl;NHPI were increased by 10.47%and 13.24%.The strategy of aryl-substituting NHPI with halogen atoms proposed in this study would provide a potential way to the development of new NHPI-based catalysts for aerobic oxidation reactions.