Research On Radical Alkylation Via Visible Light Photoredox Catalysis

Radical chemistry plays an important role in the field of organic synthesis for mild reaction conditions and good functional group compatibility.Therefore,radical chemistry has an important place in the field of organic synthesis.As the energy problem becoming worse,it is developing pollution-free organic synthetic chemistry with green and renewable light-energy that gradually occurres to chemistists.In addition,with organometallic complexes equipping a strong absorption band in the visible light region discovered by coordination chemistry,photocatalysis has boomed in the past decade.Radical reactions in photocatalysis are widely applied on the construction of the carbon-nitrogen framework,among which the construction of functionalized nitrogen-containing heterocycles is an important part of radical reaction with photocatalysis researches for introducing fluorine-containing cuts to the drug molecules.The application of light-induced free radical chemistry leads to a greener and milder development organic synthesis.In this thesis,the N-hydroxyphenyloxime chloroester（NHBC ester）developed by our research group was used to realize the light-induced Minisci reaction,and the Phth-SCF₃ developed by Munavalla was used to realize the trifluoromethylthio thioetherification of olefins.The specific work is divided into the following two aspects:1.Decarboxylative Alkylation of Heteroarenes Using N?Hydroxybenzimidoyl Chloride EstersMinisci reaction using radicals to add to electron-deficient heteroarenes is an important method to construct the framework of N-heteroarenes.We developed a light-induced Minisci reaction using the amino acid-NHBC ester.Compared with the traditional Minisci reaction,the system does not require additional oxidants and acids,and the reaction is mild.The reaction utilizes NHBC ester to provide free radicals and realizes the alkylation of N-heteroarenes under the catalysis of iridium photocatalysts.This reaction has a great applicability to amino acids and N-heteroarenes substrates.It can be applied to drug molecules and peptides,and has the ability to construct functional peptides,which will play an important role in future chemical biology research.2.Metal-free visible-light-enabled vicinal trifluoromethyl dithiolation of unactivated alkenesLight-induced method was applied to realize the trifluoromethylthio and thioetherification reaction of olefin.The reaction uses commercially available disulfide as the vulcanizing reagent,and Phth-SCF₃ reagent as the redox reagent,and is carried on with 4Cz IPN.This reaction efficiently constructs a difunctional reaction of olefins and the reaction condition is mild,moreover,two unique sulfur-containing groups can be effectively introduced into the terminal olefin.