Study On The Synthesis Of Dihydrobenzofuran Derivatives By A New Strategy Of Deiodination Of Intermediates For Dearomatization Of Iodophenols

Dihydronaphthofuran skeleton and dihydrobenzofuran skeleton are two significant molecular skeletons,which are widely present in drug molecules and natural products.The constituent atoms of naphthofuran skeleton and the benzofuran skeleton are almost completely coplanar thus they are aromatic.Yet the dihydronaphthofuran skeleton and the dihydrobenzofuran skeleton have two prochiral sp~3 carbons on the heterocycle,which allow them to break the coplanar nature of the naphthofuran skeleton and the benzofuran skeleton,and also enable them to obtain many new special properties and uses.Such as a variety of biological activities and huge potential medicinal value.Dihydronaphthofuran framework and dihydrobenzofuran framework have always been widely concerned by scientific researchers.The research work on dihydronaphthofuran compounds started from long time ago.Since the first case of 1,2-dihydronaphthalene[2,1-b]furan compound was successfully synthesized in 1948,tens of thousands of compounds with this type of skeleton have been discovered or synthesized.However,the methods of constructing the dihydronaphthofuran skeleton are obviously less than that of the dihydrobenzofuran skeleton.The research work of dihydrobenzofuran compounds has a long history.The first report on its synthesis can be traced back to 1892,and since 1909,the compound structure of the benzodihydrofuran skeleton was completely determined for the first time.So far,tens of thousands of dihydrobenzofuran compounds have been discovered or synthesized.Due to the limited sources of dihydronaphthofurans and dihydrobenzofurans in nature,the development and utilization of the biological activity and medicinal value of these two compounds are severely restricted.Therefore,it is necessary to study the construction methods of these two types of frameworks at low cost and fast through simple raw materials.This thesis summarizes the research contributions made by the predecessors in the field of framework construction of dihydronaphthofuran and dihydrobenzofuran,and elaborated the new reaction strategies we have developed to construct these two types of frameworks.We used cheap and easily available iodophenol as raw materials,and successfully prepared these two types of frameworks with?,?-unsaturated imines in the reaction mode of[3+2],under room temperature with the participation of alkalis.The specific content of this thesis consists of the following two chapters:The first chapter mainly summarized the important significance of dihydro-naphthofuran and dihydrobenzofuran bone architecture and the development process of construction methods.The second chapter described the research process of iodophenol and?,?-unsaturated imine to construct the framework of dihydronaphthofuran and dihydro-benzofuran in detail under the participation of alkali.This part included the proposal of the subject,the process of screening and determining iodophenol,the process of determining?,?-unsaturated imine,the process of optimizing reaction conditions,some mechanism experiments,etc.The possibility reaction mechanism was propose based on the existing mechanism experiment results.