New Strategy For The Preparation Of Allylic Sulfides And Sulfones Towards Its Application In Organic Synthesis

Functionalized organic sulfur compounds,especially allylic sulfide and sulfone derivatives are of great importance both in medicinal chemistry and in the preparation of organic synthetically useful intermediates.However,the existing approaches for the synthesis of organosulfur compounds usually need pre-functionalized substrates,odorous mercaptans and/or the requisite of expensive transition metal catalysts,which largely limits their application in organic synthesis.In this thesis,we use cheap and easily available dimethyl sulfoxide(DMSO)as a sulfur source and react with commercially available methyl ketone derivatives in an acidic medium.By regulating the reaction time and the order of reactants addition,various allylic sulfides and sulfones are obtained in high yields.After a series of control experiments conducted,we also proposed the possible mechanisms of such reactions respectively.Furthermore,selected molecular transformations of synthesized allylic sulfides demonstrated the utility of this approach in organic synthesis.My thesis includes three parts,which are described as follows:The first chapter summarizes the important application and traditional synthesis methods of organosulfur compounds in recent years,including the advantages and limitations.In this context,We propose the starting point and significance of our project.In the second and third chapters,we successfully implemented the allyl sulfides and sulfone compounds by controlling the reaction conditions,utilizing the strategy of in situ generation of enamine intermediates from methyl ketones and amines,and reacting with dimethyl sulfoxide in an acidic medium.We have specifically introduced this in terms of optimization of reaction conditions,substrate extension,mechanism investigation and products derivatization reactions.Finally,a comprehensive summary of our work in this thesis is presented.