Aerobic Oxidation Of Transition Metal Involved In The Study

The research works in this thesis were concentrated on transition metal mediated aerobic oxidation reactions. The reactions are all use O₂ as oxidant which is green, cheaper and very available, so the researches have a great meaning from both economic and environmental points of view.Firstly, we studied NHPI catalyzed aerobic oxidation through free radical process in ionic liquid which transition metal (Co^â…¡) was used as co-catalyst. We design and synthesized a new ionic derivative of NHPI which is named 3-pyridinylmethyl-N-hydroxyphthalimide (Py-NHPI). Both NHPI and Py-NHPI are found to have better performance in the ionic liquid than in the conventional organic solvents for the aerobic oxidation of N-alkylamides to imides. On the other hand, Py-NHPI is found to be a much better catalyst than NHPI for the aerobic oxidation of benzylic compounds in the ionic liquidSecondly, we studied palladium catalyzed aerobic oxidation of alcohols under ligand-free conditions. It was found that aerobic oxidation of electron-rich benzylic and allylic alcohols can be achieved with high yields with only 0.1 mol% of Pd(OAc)₂ catalyst in the presence of MS3A. This procedure is expected to be valuable for industrial-scale applications from both economical as well as environmental points of view.Thirdly, we studied palladium catalyzed aerobic oxidation of amines. The PdCl₂/PPh₃ procedure can successfully catalyze the aerobic oxidation of several types of amines including Ar-CH₂NHPh, Ar-CH₂NHOMe, and Ar-CH₂NHMs with high yields. In addition, we we also studied the reaction mechanism of aerobic oxidation of amines. Based on the experimental data we also give out our explanation to some reaction phenomenon.Finally, we Studied palladium catalyzed aerobic oxidative coupling of anilindes with olefins through regioselective C-H bond activation. Compared to the previous milestone work, we not only successfully used molecular oxygen to replace the chemical oxidant, but also obtained improved yields for a number of substrates. The reaction tended to give high yields for electron-rich anilides and electron-deficient olefins.