The Green Catalytic Synthesis Of Carbonyl Compounds And Derivatives

With the development of society, alcohols, ketones and their derivatives like lactones and oximes play an important role in the chemical industry. The traditional industry processes with environmental, energy costing, and health problems are required urgently to be replaced. It is important for modern chemistry to improve the utilization efficiency of chemical sources and energy by searching for greener reaction processes. The increase of efficiency relies on synthesizing new materials and/or developing new reaction paths. In recent years, one of green chemistry principles was proposed to develop new catalyst and to achieve a high utilization of the substrate atoms. The heterogeneous catalysts with designable active center, easy separation, recyclable characteristics have drawn a lot of attention. In particular, zeolites, one typical branch of heterogeneous catalysts, with porous structure, high hydrothermal ability, environmental friendly, and designable active center, have been applied in various catalytic processes.In this dissertation, focusing on the catalytic synthesis of alcohols, ketones, and their derivatives such as lactones, and oximes, that have potential applications in industry, we have synthesized various transition metals-containing zeolite materials as the catalysts for developing new routes for the clean production of K-A oil, lactones, and oximes.1. Oxidation of cyclohexane to K-A oil by CHHPThe oxidation of cyclohexane is an important chemical reaction for the synthesis K-A oil (mixture of cyclohexanone and cyclohexanol), the raw chemicals of caprolactam, adipic acid and further their polymerized products of nylon-6 and nylon-66. K-A oil is currently synthesized by the oxidation of cyclohexane. Cyclohexane is first oxidized to cyclohexyl hydroperoxide (CHHP) by oxygen, then CHHP is decomposed to K-A oil in the presence of transitional metal salt. In this assertion, we used tert-butyl hydroperoxide as a model oxidant to screen the ctalysts, then applied the chosen catalyst to the oxidation of cyclohexane with CHHP under optimized reaction parameters.2. Ammoximation of low carbon aldehydes and ketones by titanosilicatesOximes are the downstream products of aldehydes and ketones, which are important bulk chemicals with a close relationship with our life. Cyclohexanone oxime can bei rearranged to caprolactam, the precursor of nylon-6, while methyl ethyl ketone and dimethyl ketone have taken the place of hazard hydrazine and are widely used as deoxidants in the boiler. In addtion, oximes are important subtracts and intermediates in organic synthesis. Titanosilicates/H2O2 reaction system shows a high activity in ammoximation of ketones and aldehydes. Now, there are three titanosilicates active for the ammoxmation:TS-1 (MFI), Ti-MWW (MWW) and Ti-MOR (MOR). TS-1 shows a high activity in the ammoximation of bulky molecular ketones such as cyclohexanone, which has already been applied in industrial process. While for the ammoximation of low carbon aldehydes and ketones, TS-1 could further oxidize oximes to nitro-compounds. Thus, we have systematically investigated the catalytic properties of three representative titanosilicates in the ammoximation of low carbon aldehydes and ketones with3. Acetaldehyde oxime synthesis by ethylamine oxidation with W-MOR catalystAmine could be directly oxidized to oxime with H2O2 as oxidant. Up to now, only TS-1 and VS-1 were reported for this reaction. Because the reaction contains multi-steps such as oxidation and rearrangement, the oxime selectivity is poor. Tungsten based materials have shown a high activity in oxidizing cyclopentadiene to glutaraldehyde, while does not catalyze deep oxidation of aldehyde to acid. This inspired us to synthesize and apply the tungsten based zeolites to the oxidation of ethylamine to acetaldehyde oxime, in which W-MOR proved to be an effective catalyst for this reaction.4. ε-Caprolactone synthesi by Baeyer-Villiger oxidation of cyclohexanone on Mo-Beta catalyst.s-Caprolactone is a basic chemical with wide applications in chemical industries. Generally, it is synthesized by Baeyer-Villiger oxidation of cyclohexanone with peracids. This stoichiometric process are facing serious problems of pollution and energy consuming. The new process for synthesizing ε-caprolactone from cyclohexanone is based on the tin-based catalysts and H2O2. While because of an easy hydrolysis of s-caprolactone, its selectivity is relatively poor. In this assertion, we have designed new catalyst of Mo-Beta. Through modifying this catalyst with fluorine, and investigating the reason for lowering the lactone selectivity, we have enhanced greatly the selectivity over 95% on either Mo-Beta or conventional Sn-Beta catalysts.