Organic N-hydroxyphthalimide catalyzes the selective aerobic oxidation of hydrocarbons promoted by the nonionic surfactants through hydrogen bonding effect

Metal-free catalytic selective oxidation of hydrocarbons is a green and challenging process for the manufacture of oxygen-containing chemicals. A nonionic surfactant of polyethylene glycol (PEG) was developed as the co-catalyst for N-hydroxyphthalimide (NHPI) to form a novel metal-free organic catalytic system NHPI/PEG, with which the efficient oxidation of a series of hydrocarbons including toluene, fluorene, ethylbenzene, and p-xylene was realized. PEG could facilitate the generation of active free radical phthalimide N-oxyl (PINO) through hydrogen bonding effect, and the decomposition of intermediate of phenylethyl hydroperoxide and oxidation of 1-phenylethanol could also be obviously improved especially at the presence of PEG. The present work provides a novel electronic promoter for the NHPI-based catalytic system and demonstrates the promoting efficiency of hydrogen bonding interactions on modulating the catalytic activity of organic catalytic system.