A highly efficient transformation from cumene to cumyl hydroperoxide via catalytic aerobic oxidation at room temperature and investigations into solvent effects, reaction networks and mechanisms

Cumyl hydroperoxide (CHP) is an important intermediate for the production of phenol/acetone, but suffers from severe reaction conditions and a low yield industrially. Here, an efficient transformation from cumene to CHP was developed. Different solvents were modulated for cumene oxidation catalyzed by NHPI/Co, and reaction network and mechanisms were investigated methodically. Hexafluoroisopropanol (HFIP) markedly promoted the transformation from cumene to CHP compared to other solvents at room temperature. A cumene conversion high up to 64.3% were observed with a selectivity to CHP of 71.7%. The solvent HFIP exhibited a significant promotion on cumene oxidation due to its contribution to the enhancement of the concentration of PINO radicals. Moreover, cumyl, cumyl oxyl and methyl radicals were captured by TEMPO and analyzed by HRMS, and the reaction paths and mechanisms from cumene to products were inferred. The preparation method discovered in this work may open an access to the production of CHP. [Display omitted] •A highly efficient conversion from cumene to cumyl hydroperoxide was developed.•A cumene conversion of 64.3% & a selectivity to CHP of 71.7% were observed at RT.•A reaction network from cumene to CHP and byproducts were well built.•The key free radicals were captured and the catalytic conversion was rationalization