Research On Catalytic Co-oxidation Of Cyclohexanone With Benzylic Compounds By Molecular Oxygen

The origination, development and actuality of catalytic co-oxidation are briefly reviewed in this paper. Four gradations have been proposed based on catalytic principle and application as follows: co-oxidation existing in life body universally and enzyme-catalysis models; direct application of organic peroxide as oxidant or catalyst in chemical oxidation; co-oxidation of target species directly with the substances (e.g. aldehyde) which could generate radicals via itself oxidation; co-oxidation of target species indirectly with the substances which could generate radicals via chemical transformation then oxidation. The industrial availability of indirect co-oxidation methods has been predicted based on comparison of the three chemical methods about organic peroxide as oxidant or catalyst, direct co-oxidation and indirect co-oxidation. Meanwhile, summarizing on advancement and actuality briefly about catalytic oxidation of benzylic compounds lead to the beneficial imagination of cyclohexanone as co-oxidation initiator. The benefits include milder conditions, faster rate, higher selectivity, simplier after-treatment, moreover promoting the theoretical research on catalytic co-oxidation.In virtue of literature investigation and information selection, the catalytic systems and reaction conditions were preliminarily established. Then, the research was deployed from four aspects: (1) catalytic oxidation of cyclohexanone by molecular oxygen; (2) catalytic co-oxidation of toluene and substituted toluene with cyclohexanone; (3) catalytic co-oxidation of ethylbenzene (as representative of aromatics excluding substituted toluene) with cyclohexanone; (4) exploration and speculation of the co-oxidation mechanism.By the selection of catalysts and investigation about influence of solvents, reaction temperature, the relative amount of cyclohexanone and catalysts on the reaction, a good method for cyclohexanone oxidation to adipic acid had been put forward.That is CuCl2·2H2O as catalyst, n-butyl acetate as solvent at 90℃in the condition of atmosphere pressure when molecular oxygen is used as oxidant. The conversion of cyclohexanone and yield of adipic acid could be reached respectively to 94.4%, 90.5% for 10h.Oxidation of xylene had been found simultaneously while cyclohexanone was attempted to oxidize in the xylene as solvents. However, the oxidation of xylene couldn't occur without...