Study On Fluorination Functionalization Of Activated Olefins

With fluorinated alkyl structures,Organic compound molecules have a special physiological activity,and are widely used in many fields such as pharmaceutical,pesticides,materials and etc.Fluothane intermediate,which is formed by introducting difluoromethyl（CF₂H）into alkene compounds,is been extensively used in the pharmaceutical field.In recent years’researches,as an effective difluoromethylation reagent,difluoromethyltriphenylphosphorous bromide（[Ph₃PCF₂H]⁺Br^-）has drawn widespread attention to people for its usage in photochemical reactions as a precursor of difluoromethyl radicals in photochemical reactions.When it plays a part in researches about the difluoromethylation（CF₂H）of olefins,many researches require additives and photocatalysts.In this paper,under photocatalytic conditions,catalytic electron transfer compounds strategy was used to achieve the synthesis of difluoromethyl（CF₂H）enamine compounds.With mild conditions,simple operation,and good substrate universality,this reaction not require photocatalysts,and it provides a new simple method for the preparation of fluorinated compounds.On this basis,the method of using ethoxycarbonyl fluoromethyl phosphorus bromide as a fluoroalkylation reagent is also feasible,and this strategy can also achieve the synthesis of fluoromethylated oxidized indole compounds.Under visible light irradiation and the presence of sodium iodide（Na I）,a catalytic amount,by using difluoromethyltriphenylphosphorous bromide（[Ph₃PCF₂H]⁺Br^-）as substrate and N,N-dimethylformamide（DMF）as solvent,can the reaction be carried out.The main research contents are as follows:The template reaction uses difluoromethyltriphenyl phosphorus bromide,ethoxycarbonyl monofluoromethyl phosphorus bromide,and activated olefins as reaction substrates.The optimal conditions are determined and the universality of activated olefin substrates is investigated.This method has good universality and functional group tolerance,and high yield.The reaction mechanism was explored through UV/Vis spectroscopy and free radical capture experiments.