Visible-Light-Promoted Fluorinated Pyrimidines,Triazines Construction Initiated By Electron Donor-Acceptor Complex

Visible light is one of the most ideal and green energy sources for human society in the future due to the nature features,that is,rich,green,non-polluting and renewable energy.Therefore,the application of visible light in synthesis has become the theme that chemists have been pursuing in the 21st century.At present,the utilization of visible light is roughly classified into three types according to the mechanism of occurrence,(1)photoredox reactions.(2)Energy transfer reactions.(3)The reactions initated by EDA complex.Electron donor-acceptor(EDA)complex,that is,charge transfer complex,which is formed on the basis of intermolecular non-covalent weak interaction between electron-deficient electron acceptors and electron-rich electron donors,is similar to the halogen bond or hydrogen bond.Visible-light-promoted organic syhthesis reactions,which mediated by EDA complex,are more green,economical than photo-redox,but challenging.Based on the characteristics of green and sustainable synthesis of visible-light-promoted reactions initiated by EDA complex,this thesis mainly studies the utilization of visible light-promoted reactions,which initiated by EDA complex and combined multicomponent chemistry and the oxygen-catalyzed method,synthesizing a serious of heterocyclic compounds,such as fluorined pyrimidines,and triazines.The major research contents include the following six chapters:The chapter one briefly introduces the importance of constructing a heterocyclic skeleton and the types of visible light involved in the reaction.The main conclusions are summarized the formation and characteristics of EDA complex and the photosynthetic reactions based on EDA complex.On the bases above,the topic basis of the paper was proposed.A visible-light-promoted one-pot and three-component protocol for the synthesis of polyfluoroalkylated tetra-substituted olefins and pyrimidines have been developed in the chapter two and three.The formation of EDA complex between enol anion(electron donor)and the polyfluoroalkyl iodides(electron acceptor)enable the process with different nucleophilic reagents as an additive.The fourth chapter is based on the research in the second and third chapter,According to the above mechanism,when the enolate anions were replaced by biguanide anions,6-polyfluoroalkyl-s-triazines have been successfully synthesized with polyfluoroalkyl iodine.The reaction process involves C,N radical-radical combination intramolecular nucleophilic substitution and 6πelectrocyclization,aromatization.Photo-and oxygen-enabled radical C(sp~3)―N(sp~2)cross-coupling:Synthesis of N~2-perfluoroalkacylguanidines have been developed in the chapter five.This reaction involves consecutive energy transfer and electron transfer during the formation of the ternary charge transfer complex and the dioxygen is used as an electron shuttle during the reaction.The chapter six summarize the major viewpoint and point out the innovation and the deficiency of this paper.Finally,proposing the forecast to the further research for EDA complex in synthesis.Further studies focused on the application of synthesed compounds in the field of materials,are underway.