Selective Oxidation Of Alkylarenes With Molecular Oxygen

This dissertation consists of two parts: (1) selective oxidation of alkylarenes with molecular oxygen in ionic liquid/HOAc/Co²⁺ /AIBN; (2) the application of quaternary ammonium salts in the selective oxidation of alkylarenes with molecular oxygen.Part I. Selective oxidation of alkylarenes with molecular oxygen in ionic liquid/HOAc/Co²⁺ /AIBN.Selective oxidations of alkylarenes with molecular oxygen in different ionic liquid/catalysts systems were investigated, and the influence factors for the selectivity and conversion were inspected. The main results were as follows:1. We developed a new reaction system [Hex-mim]⁺BF₄^-/Co(OAc)₂/ HOAc//NaBr/AIBN, in which p-xylene could be oxidized effectively to the corresponding aldehyde and alcohol by molecular oxygen under atmospheric pressure. The conversion was up to 95.9%, and it was superior obviously to the earlier results.2. We also developed one method for adjusting the selectivity by adding right amount of water to the reaction system. The selectivity for the product aldehyde was enhanced while increased the quantity of water, however, the conversion was decreased under this condition. When the ratio of water to ionic liquid was 7/10, both of the selectivity and conversion were satisfactory.3. The experimental showed that the conversion could be improved while increasing the acidity, but it was nearly not changed when the acidity was increased to a certain degree. Continuation of increasing the acidity led to the formation of aromatic acid. Lengthening the reaction time and increasing the quantity of ionic liquid did not influence the conversion and selectivity.4. The oxidation of different substrates indicated that the conversion was influenced obviously by electronic effect. The electron-donating groups on aromatic ring was favorable to the reaction, contrarily, the electron-withdrawing groups decreased the conversion.Part II. The application of quaternary ammonium salts in the selective oxidation...