Application Of Selenium And Iron-Containing Catalysts In Oxidative Deoximation Reactions

Deoximation reaction is an important process to convert oximes into the corresponding carbonyl compounds.It is not only used for the protection and deprotection of carbonyls,but also be used for separating and purifying carbonyl compounds,which provides new ideas and methods for the synthesis of carbonyl compounds.At present,the reported methods for deoximation include the acid hydrolysis,oxidation,reduction,electrochemistry,etc.Among them,there are many reports on the transition metals-catalyzed oxidative deoximations.However,the high cost and transition metal pollution issues restrict their application in industrial level production.Therefore,developing environment-friendly and economical metal or non-metal catalyzed deoximation technology is in line with the development trend of chemical industry.Iron and selenium are essential trace elements for human body,which can be metabolized.Therefore,they are safer than most of the transition metals.In addition,China has abundant iron and selenium resources,and it will have a good strategic significance to give full play to the advantages of resources.In this thesis,the catalytic systems and materials based on iron and selenium have been developed,and they have been successfully applied in the deoximation reactions.The details are as follows:1.The oxidative deoximation reaction catalyzed by FeSO4 and benzophenone was studied.In this method,catalytic amount of iron salt and benzophenone were used as catalyst,air as oxidant and dimethyl carbonate as solvent.For some substrates,it is necessary to use clean and cheap oxygen as oxidant or increase temperature to maintain stable yield.2.The oxidative deoximation reaction catalyzed by selenium/carbon(Se/C)using glucose as carbon source was studied.Glucose was selected as the best carbon source from many carbohydrates,and a series of Se/C materials were prepared by selenization and calcination.In oxidative deoximation reaction,Se/C shows high catalytic activity.It was interesting that,for the case using ethyl-2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate as substrate,Beckmann rearrangement occurred instead of the desired deoximation reactions3.The design of Selenium/iron(Se/Fe)material and its application in oxidative deoximation reaction were studied.The Se/Fe materials prepared by grinding and calcining iron powder and selenium powder do not show high catalytic activity in the oxidative deoximation reaction.But the characterization proves that its main component is Fe2Se2.Compared with the traditional method of preparing Fe2Se2,this method has the advantages of simple,economical and green.In conclusion,the catalyst systems and materials containing Se and Fe in this paper could catalyze the deoximation reactions under relatively environment-friendly conditions.