Study On Electrochemical Oxidation C-C Bond Coupling Reaction And Unactivated Olefins Bifunctionalization Reaction

Organic electrochemical synthesis is an interdisciplinary subject that combines electrochemistry with organic synthetic chemistry.Compared with the traditional synthetic chemistry,in the organic electrochemical synthesis,electrical energy is used as the driving force and electrical current is used as reaction reagent.The reaction undergoes an oxidation reaction at the anode and a reduction reaction at the cathode,thus avoiding the use of expensive and toxic chemical oxidants and reducing agents from the source.More importantly,electrochemical synthesis reaction has unique controllability,the chemoselectivity of electrochemical reactions can be effectively achieved through a granular level of control its voltage and current.Thereby,it provides a new protocol to realize chemical reaction that traditional organic synthesis reaction unable to achieve.Therefore,electrochemical organic synthesis has become a"sustainable scientific discipline"in scientific research,industry,and biomedicine.This thesis focuses on the electrochemical oxidative C-C bond coupling reaction and the electrochemical oxidation of non-activated olefin intramolecular difunctional reaction.First Chapter reviews the research progress of electrochemical coupling reaction and olefin bifunctional reaction in the past ten years.Based on the electrochemical C-C bond coupling reaction and olefin bifunctionalization reaction,a nitrogen-containing heterocyclic C(sp~2)-C(sp~2)coupling reaction was reported,and a new method of producing alkyl radicals by deoxidation of alcohols under electrochemical conditions was introduced and applied to the free radical coupling reaction with nitrogen-containing Heterocyclic C(sp~2)-C(sp~3)and the study of the difunctionalization of the non-activated olefins.Details are as following three parts:1.Study on the Anodic Oxidative Homo-Coupling Reaction of Imidazopyridine HeterocycleIn this chapter,we have developed the self-coupling reaction of the imidazopyridine ring of the drug molecular framework under electrochemical conditions.Tetrabutyl hexafluorophosphate is used as the electrolyte in the undivided cell with graphite electrode as anode and platinum electrode as cathode,and acetonitrile and trifluoroethanol as mixed solvents.The self-coupling products can be efficiently obtained by energizing at room temperature for 4.5 hours at a constant current of 2m A.This reaction avoids the use of oxidants and has good reaction compatibility.It is also compatible with imidazopyrimidine and imidazothiazole,and the reaction has high regioselectivity,which provides a new way for the synthesis of bicyclic heterocycles.2.Study on the electrochemical deoxygenativecoupling reaction of nitrogen-containing heterocycles with alcoholsAlcohols are one of the most common and widely sourced chemicals in the laboratory and chemical industry,and they have a wide variety of molecular structures.The generation of alkyl radicals through the deoxidation of alcohols has important significance in the field of free radical chemistry.However,the higher temperatures,metal catalysts,and large amounts of oxidants are inevitably used due to the higher C-O bond energy of alcohols.In this chapter,we first report the synthesis of hydrazine formate from alcohols as redox active esters.The conversion of alcohols to alkyl radicals was carried out efficiently under electrochemical conditions,and the coupling reaction with a series of containing nitrogen heterocycles was realized using this strategy.This sustainable method avoids the use of catalysts and oxidants,the reaction can be achieved at lower temperatures,and is well compatible with primary,secondary,and tertiary alcohols.3.Study on the electrochemical intramolecular alkynyl/alkenyl migration for the difunctionalization of unactivated alkenesThe difunctionalization reaction of alkenes by electrochemical oxidation has attracted extensive attention in recent years and has become a research hotspot in the field of electrochemical synthesis.The previous reactions have mainly focused on the difunctionalization of activated olefins,and the difunctionalization of unactivated olefins are less developed.The highlight of this chapter is the first report on the difunctionalization of non-activated olefins by intramolecular migration of functional groups under electrochemical conditions.This reaction has good compatibility of functional groups,high yield,mild reaction conditions,using the reaction substrate(sodium benzenesulfonate)as electrolyte can avoid the addition of extra electrolyte,which meeting the new trend of modern electrochemical synthesis reaction and providing a new strategy for the difunctionalization reaction of unactivated olefins.