Catalytic oxidation of hydrocarbon with the organic metal-free system of N-hydroxyphthalimide/tert-butyl nitrite at room temperature

Catalytic oxidation of hydrocarbons under mild conditions is a meaningful and challenging process. N-hydroxyphthalimide (NHPI) combining with tert-butyl nitrite (TBN) as the promoter was used in 1,2-dichloroethane (DCE) to efficiently catalyzed the oxidation of fluorene to fluorenone. At room temperature, both conversion of fluorene and selectivity of fluorenone reached 96%. The presence of TBN facilitated the dissolution of NHPI in the weakly polar solvent of DCE, and then the active phthalimide N-oxyl radical (PINO) was efficiently generated under the synergistic action of TBN and DCE. With the present NHPI/TBN system, the efficient oxidation of a series of hydrocarbons under mild conditions was also realized.