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Research On A Novel Oxidation Based On Urea-hydrogen Peroxide (UHP) And Its Application In Organic Synthesis

Posted on:2014-05-26Degree:MasterType:Thesis
Country:ChinaCandidate:S M HuFull Text:PDF
GTID:2321330542456000Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
Epoxide reaction is one of the most important reactions in organic synthesis.The current methods of epoxidation in industry have many disadvantages such as serious environmental pollution,equipment corrosion,high energy consumption,high cost,complicated process and post-processing,much byproduct.Therefore,developing a novel method for the environment-friendly epoxidation of olefins is significance both in theory and in practice.Payne reaction is a kind of olefin epoxidation reactions with nitriles and hydrogen peroxide.The hydrogen peroxynitrite acid is actual oxidizer.The mechanism is similar to that of peroxoic acid.Payne reactionís weakly alkaline conditions avoid the acidic environment of the conventional epoxidation,and thus have good functional group compatibility.It was been reported that Payne reactions required high concentration of hydrogen peroxide,process control requirements with low yield.This thesis improved the Payne reaction,which using green oxidant urea-hydrogen peroxide(UHP)instead of aqueous hydrogen peroxide.This thesis makes a systematic study of reaction temperature,solvent,alkali,nitrile species,UHP amount and other factors.It was found that when the nitrile is benzonitrile,alkali as of KHCO3,the UHP amount for 3.50eq,the reaction temperature of 30 ?,the solvent of methanol and the time of 8h,the conversion,yield and selectivity are highest,which is 98.7%,90.3%,91.5%.A range of alkenes was epoxidized by this method providing yields ranging from 79.0%to 96.0%.And this thesis improves the Payne reaction to sulfide oxidation and N-oxidation,which get good consequence.Each yield ranges from 72.3%to 98.5%and 42.5%to 91.3%.Payne reaction in this thesis retained the traditional Payne reactionís advantages,and gave full play to the UHP as a solid-state hydrogen peroxide.Its high hydrogen peroxide content and the potential for releasing it in a controlled manner,as well as its solubility in organic solvents and environment-friendly byproduct make it a good substitute for organic synthesis and industry.The reaction will contribute to make the oxidation reaction environment-friendly.
Keywords/Search Tags:Alkenes, sulfide, sulphoxide, sulphone, N-Oxides., Payne epoxidation, nitrile, urea-hydrogen peroxide(UHP), peroxycarboximidic acid, oxidation
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