Study Of The Decarboxylative Difluoroacetylation Of Cinnammic Acids Via Photoredox/Copper Dual Catalysis

Fluorinated substituents represented by difluoroalkylation have been widely concerned by industry and academia because of their unique biological activity and chemical properties in materials and pharmaceutical research,but the introduction of difluoroalkyl group in organic synthesis.The classical method of introducing the group has the shortcomings such as harsh conditions,expensive reagents and poor environmental friendliness,so it is necessary to find a new synthetic method with simple operation,high reaction efficiency and environmental friendliness.In this thesis,the photoredox/transition-metal dual-catalyzed decarboxylation coupling reaction of cinnamic acid using ethyl iodo difluoroacetate as fluorine source has been studied.The thesis could be divided into three chapters:We intend in the first chapter to showcase the major and the most relevant advances made in the field of functionalized difluoromethylene group introduction and the related mechanism.Herein,we would like to highlight the functionalization of C(sp2)centers(arenes and alkenes)to access to difluoromethylated derivatives and summarize the application of corresponding new synthetic methods.The second chapter briefly introduces the progress and prospects made in the field of visible light photocatalysis and photoredox dual catalysis.Herein,we would like to focus on the application and mechanism of photocatalysis and photoredox dual catalysis in organic synthesis methodology.The third chapter mainly introduces the photoredox/transition-metal dual-catalyzed decarboxylation coupling reaction of cinnamic acid using ethyl iodo difluoroacetate as fluorine resource.The reaction was carried out at room temperature with methylene chloride as the solvent,and twice the amount of triethylamine was used as base.The reaction was stired for 12 hours.The substrate was catalyzed by the dual-catalyst system consisting of photoredox catalyst and transition-metal catalyst.A series of ?,?-unsaturated difluoroacetyl products were obtained by this method.At the same time,we have studied the applicability of the substrate and put forward the reasonable reaction mechanism through the relevant verification experiments.The structure of the product was determined by 1H NMR,13 C NMR spectrum.The method is focused on the traditional method of introducing difluoralkyl group and the decarboxylation coupling reaction using photoredox/transition-metal dual catalysis has been studied.This method is simple,environmentally friendly and efficient.