A Complexation Promoted Organic N-Hydroxy Catalytic System for Selective Oxidation of Toluene

Complexation was innovatively utilized to design a novel catalytic system for the selective oxidation of toluene, which runs contrary to the traditional definition of organic metal complex catalysis. In the present system, an N-heteroaromatic ring-containing N-hydroxy compound acts as the catalytically active component. Through an electron-withdrawing effect produced by the occurring complexation with proper metal salts, which was characterized by real-time in situ Fourier transform infrared spectra, the activity of the organic molecule could be remarkably improved. The combination of copper(II) chloride with 6-hydroxy-pyrrolo[3,4- b]pyrazine- 5,7-dione showed the best activity, and an inert hydrocarbon such as toluene could be efficiently transformed with 70.9% conversion and 93.5% selectivity to benzoic acid at 90 degrees C within 2 h.