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The Research On Catalysis Of Simple Metalloporphyrins For Oxidation Of Olefins With Molecular Oxygen

Posted on:2011-08-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y F LiFull Text:PDF
GTID:1111330371964419Subject:Organic Chemistry
Abstract/Summary:PDF Full Text Request
Alkenes possess more active chemical property than saturated alkanes due to its C=C double bonds. The oxidation products of alkenes are various owing to its versatile molecular structures and chemical properties. Alkenes can be oxidized to the compound containing oxygen atom such as epoxide, aldehyde, ketone, carboxyl acid, etc, which are important raw materials for petrochemical industry. Therefore, how to control the extent of oxidation and selectivity of alkene oxidation is important and difficult point in the research field of catalytic oxidation of olefins. And it is important for catalytic oxidation of alkenes to utilize O2 as oxidants.In this paper, the reaction using the simple metalloporphyrin as catalyst and O2 as oxidants was studied. We investigated the effect of metalloporphyrin and reaction condition on the catalytic reaction. And the catalysis and mechanism of oxidation and cis-trans isomerization of alkenes were discussed by a series of designed experiments. The research results indicate that the alkenes such as diphenylethene derivatives can be oxidized as epoxide and aldehyde with O2 in the presence of metalloporphyrin. Moreover, the isomerization reaction from cis-diphenylethene to trans-diphenylethene can be catalyzed by tetraphenylporphyrin manganese (TPPMnCl) in the presence of O2, which has been not reported in the literature. The contents of this thesis are presented as follows:1. Porphyrin compounds and metalloporphyrin compounds with different metal ions were synthesized as catalyst according to Alder's method. In addition, five diphenylethene compounds are synthesized by Wittig reaction from triphenylphosphine and substituted benzyl chloride. Then, the effects of diphenylethene compounds with different substitutes on the oxidation reaction were investigated.2. The oxidation reaction of styrene with O2 catalyzed by metalloporphyrin was studied and the effects of catalyst and reaction condition on catalytic reaction were investigated. And styrene can be oxidized as epoxide and aldehyde catalyzed by tetraphenylporphyrin manganese (TPPMnCl). The total conversion was 90% and the selectivity of epoxide is 42%. In addition, we studied the change of reaction products with time. The experimental results showed that tyrene was oxidized as epoxide or aldehyde is competitive.3. The oxidation reaction of diphenylethene derivatives with O2 catalyzed by metalloporphyrin was studied and the effects of catalyst, reaction condition and substrate structure on catalytic reaction were investigated. Normalization method and effective carbon number theory are used to calculate the quantification of the products. The main products are trans-epoxide and aldehyde caused by cleavage of double bonds, and the selectivity of epoxide is above 80%. The experimental results indicated that the rate of oxidation reaction was gradually slow with increasing electron donating ability of substitutes of diphenylethene. The effects of chemical structure of substrate such as styrene,β-methylstyrene and diphenylethene on the reaction were studied.4. The effect of cis-trans configurations of substrate on the reaction, the stereoselectivity of epoxide product, the relative selectivity of epoxidation and cleavage reaction of C=C double bonds, the effect of solvent on the reaction, and the function of DMF in the reaction were studied. And a potential mechanism about the oxidation reaction of styrene catalyzed by simple metalloporphyrin is also proposed by this research.5. The catalysis and mechanism of metalloporphyrin towards cis-trans isomerization of alkenes were studied. The research results show that the isomerization reaction from cis-diphenylethene to trans-diphenylethene can be catalyzed by tetraphenylporphyrin manganese (TPPMnCl) and can not be catalyzed by tetraphenylporphyrin iron (TPPFeCl) in the presence of O2, which has been not reported in the literature. And the catalysis and mechanism of TPPMnCl toward cis-trans isomerization of alkenes were discussed by a series of designed experiments.
Keywords/Search Tags:Metalloporphyrin, Alkenes, Molecular oxygen, Catalyze, Oxidation
PDF Full Text Request
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