Studies On Visible Light-Induced Copper-Catalyzed Coupling Reaction Of Oxime Esters And Sodium Sulfinates

Oxime ester is one of the important organic compounds in nature,and there are commonly found as structural units in a variety of natural products,drug molecules and functional materials.They are an important building block for organic synthesis,with simple synthesis and ease of preservation,and have a wide range of applications in organic synthetic chemistry.In recent years,synthetic chemists have used oxime esters as primary materials to catalyze the formation of highly active imine radicals,and have efficiently achieved C-C bond cleavage,C（sp³）-H functionalization and cyclization reactions.However,currently reported reactions are mainly based on thermal reactions under the catalysis of transition metals such as Rh,Pd,Cu and Fe,as well as photo reactions facilitated by the complex of precious metals Ir and Ru.In addition,sulfones,as an important class of compounds,are widely present in materials,natural products,and pharmaceutical molecules.They can exhibit diverse biological activities and medicinal values in certain aspects.However,the synthesis of sulfone compounds involving oxime esters under visible light promotion has rarely been reported.Therefore,the development of a novel method for the functionalization of oxime ester that is in mild conditions,easy to operate,and practicable is of great academic significance and application prospects for the synthesis of sulfone compounds.Based on the previous research,this thesis aims to address the shortcomings in the reaction between oxime esters and sodium sulfinates and the construction of multifunctional pyrroline skeleton.We have developed a dual-functional catalytic system based on inexpensive copper,which has enabled C（sp³）-H functionalization reactions to occur at theα-andδ-positions of oxime esters.As a result,we could efficiently synthesisβ-ketone sulfone derivatives and multifunctional pyrroline molecules.This thesis is mainly divided into the following three parts:1.Visible light-induced copper-catalyzed free radical cross-coupling reaction of arylketones and oxime esters with sodium sulfinatesBased on the copper-based dual-functional catalytic system,we have developed a mild,green,and efficient approach to produceβ-ketone sulfone compounds,by catalyzing the coupling reaction between oxime esters and sodium sulfinates under visible light induction.This strategy can obtain the corresponding compounds in moderate to excellent yields while adhering to mild processing conditions.One notable feature of this reaction is that the Cu（BINAP）（Me CN）PF₆ catalyst,which functions as a photo-oxidation-reduction catalyst as well as a coupling catalyst,making the reaction have good functional group tolerance and substrate compatibility for both aryl and alkyl-substituted sodium sulfinates.Moreover,this dual-functional catalyst exhibits exceptional catalytic activity,enabling the synthesis ofβ-ketone sulfones on a gram-scale preparation of using only 0.25 mol%.The efficacy of this method has been applied to the synthesis of natural active molecules.2.Synthesis of multifunctional pyrroline by visible light-induced copper-catalyzed cross-coupling reaction ofγ,δ-unsaturated oxime esters and sodium sulfinatesWe have developed a novel approach for synthesizing multifunctional 1-pyrroline derivatives through visible light-induced copper-catalyzed cross-coupling reaction ofγ,δ-unsaturated oxime esters and sodium sulfinates.This method showcases remarkable features such as low catalyst loading,good substrate versatility,and strong functional group compatibility.Additionally,it can efficiently introduce a variety of functional groups,such as Ts,SCN,I among others,into pyrroline skeleton under mild conditions,providing a new method for introducing pharmacophore groups in pyrroline derivatives with natural biological activities.