The Application Of Perfluoroalkyl Halide In Visible Light Reaction:Construct C-C And C-N Bonds

Visible light induced organic synthesis has become a hot topic in the field of organic synthesis in the past few decades.In combination with the important position of fluorinated compounds in the medical field,we have tried to develop one protocol using perfluoroalkyl halide induced by visible light as fluorine sources to construct C?C and C?N bonds.This paper is divided into four chapters.In the first chapter,it introduces the background and theoretical basis of the research and the reactions of perfluoroakyl halide are reviewed,describes the clue and purpose of topic selection briefly.In chapter II,a new way promoted by visible light for the synthesis of aza?tricycles containing a perfluoroalkyl group is developed.In this method,aza?tricycles are synthesized by the process of three-component radical cross-coupling,Michael addition and cyclization cascade reaction,which is approached by stimulating the EDA complex generated in situ by visible light,starting from ?-ketone ester,perfluoroalkyl halide and cyclic amidine-DBU.These compounds,due to the intraand intermolecular multiple weak interactions and the nonplanar and rigid nature of molecules in solid state,have AIE character which is supported by experiments.It was also found that these compounds have the propertie of acid-induced fluorescence enhancement,this provides more potential chances to apply these molecules.In chapter III,a novel strategy for the synthesis of 2?perfluoroalkyl benzimidazoles by C?N radical cross-coupling and intramolecular cyclization is described.The mechanism study shows that,in this reaction,hydroxide anion is used as the electron donor to form EDA complex in suit with perfluoroalkyl halide then excited by visible light,thus leading to SET and initiating the reaction followed by radical cross-coupling and molecular inner ring to obtain the target product.What makes this reaction different is the cross-coupling of two highly active(transient)free radicals assisted by oxygen,which is the attraction of this reaction.This strategy provides a mild reaction route for the synthesis of 2-perfluoroalkyl benzimidazole derivatives with medicinal value from simple raw materials which are cheap and easy to obtain.In chapter IV,a method of preparing diamide compounds by hydrolysis of imide intermediate which is generated after C?N free radical coupling is described.Here,biamides were synthesized via free radical coupling of o?phenylenediamine compounds and perfluoroalkyl halide in the presence of sodium hydroxide.However,this method can produce biamides without monoamides,providing a new way to synthesize perfluoramides.In general,as an excellent electron acceptor,perfluoroalkyl halides have been widely used in the field of EDA complexes which is promoted by visible light in organic synthesis.In the future,more green and efficient synthesis methods will be developed by related research groups.