Study On Light-induced Cyclization Tandem Reaction Of Fluoroalkyl Based On Non-covalent Interaction

Fluorine-containing heterocycles(fluorine-modified heterocycles)compounds play a privileged role in pharmaceuticals,agrochemicals,and functional materials.Therefore,it is very important to be able to find an efficient method for synthesizing fluorine-containing heterocyclic compounds.Electron donor-acceptor complexes bound by non-covalent interactions can produce free radicals under light induction,fluorine-containing heterocycles can be constructed by addition/cyclization tandem reaction of heteroatomic olefin.Since no additional photocatalyst,it is a simple,green,and atom-economic synthesis strategy.At present,the methods for synthesizing fluorine-containing heterocyclic compounds are still very limited.Therefore,based on the construction of fluorine-containing heterocycles,this article uses light-induced weak interaction to construct fluorine-containing heterocycles,and specifically expands three types of fluorine-containing heterocycles: 1)Cyclization of fluoroalkyl groups to construct fluorinated benzodihydrofuran;2)Synthesis of fluorine-containing aziridine;3)Synthesis of fluorine-containing tetrahydropyrrolidine.Objective: Develop a light-induced fluoroalkyl radical cyclization tandem reaction that does not use transition metals or photocatalysts to construct a fluorine-containing heterocyclic ring,at the same time,realize the gram-level reaction and corresponding derivatization.Methods: 1)Fluorinated benzodihydrofuran can be obtained by addition/oxygen cyclization tandem the double bond of fluoroalkyl radicals with o-allylphenol as the substrate;2)N-allylanilines combine with fluoroalkyl iodides to form a non-covalent interaction between N and C-I bonds,which could induce a radical intermediate and produce radical addition nitridation reaction under the irradion of visible light,thus leading to the formation of high-tension fluorine-containing aziridines;3)Fluorinecontaining tetrahydropyrrolidine can be generated by radical addition/carbon cyclization under visible light with N,N-diallyl aniline and fluoroalkyl iodide as substrates.Result: The EDA complex combined by non-covalent interaction force realizes single electron transfer under light induction,generates fluoroalkyl radicals to the unsaturated bond addition/cyclization tandem,and achieved the fluorine-containing benzodihydrofuran,fluorine-containing aziridine and fluorine-containing tetrahydropyrrolidine construction.Conclusion: Fluoroalkyl halohydrocarbons can form EDA complexes with a series of electron donors through non-covalent interaction forces,produce single electron transfer under the induction of visible light,generate fluoroalkyl radicals.Unsaturated bonds can undergo further tandem cyclization to construct different types and sizes of fluorine-containing heterocycles.It provides a concise and efficient strategy for the construction of fluorine-containing heterocycles,at the same time,it can scale up and derivatize on a gram scale,and provides new ideas for the synthesis of some important functional fluorine-containing heterocyclic molecules.