Studies On The Oxidation Of Olefins With Green Oxidants

In this paper, with the use of "green oxidant", O₂ and H₂O₂ (dilute hydrogen peroxide), much research work has been made on the oxidation of olefins, especially on the epoxidation of olefins and on the Wacker oxidation of terminal olefins bearing electron-withdrawing groups.In the whole period of studies, we had hoped to discover a new catalyst for epoxidation of olefins, forming a new epoxidation system. We had also anticipated to develop or to improve an epoxidation system, making it more effective for some substrates. We planed to study the behaviors of some terminal olefins bearing electron-withdrawing groups on Wacker reaction under supercritical carbon dioxide conditions.We have attained our aims preliminarily:1. Based on great deal of experimental research work, we discovered that a catalytic amount of simple amines, especially tert-BuNH₂, could catalyze the epoxidation of cyclicα,β-unsatureated ketones. For those which having no forking-groups, complete conversion (100%) and high selectivity (100%) were obtained.2. We have developed MnSO₄-based epoxidation system. By adding some co-catalyst and/or co-oxidant, we have improved the system's epoxidation ability. Forα-pinene, 81% GC yield were obtained in this system. The modified system even showed some epoxidation ability to terminal olefins to a certain extent.3. Aerobic oxidation of methyl vinyl ketone was performed in supercritical carbon dioxide with some methanol in presence. It was found that the products are mixture of Michael-adduct and acetal. The effects of co-catalyst, additive, pressure and temperature to the reaction were studied in detail.4. In supercritical carbon dioxide, the Wacker oxidations of acrolein and of acrylic acid were also studied.