Research On The Functionalization Of Unsaturated Bonds Under Electrochemical Conditions

The introduction of various functional groups is an important method for the improvement of drug activity,the modification of material functions,and the mutual conversion between various chemical raw materials.For some compounds containing unsaturated bonds,a series of organic reaction types such as oxidation,addition,and reduction can occur due to their special chemical properties,thus introducing carbonyl,hydroxyl,cyano,trifluoromethyl,amino,etc.Both alkenes and alkynes contain carbon-carbon πbonds,and alkenes and alkynes show great advantages in the introduction of functional groups due to the characteristics of the electron cloud distribution of the π bonds.Therefore,the introduction of single and multiple functional groups from alkenes and alkynes has been favored in recent years.The Kolbe electrolysis reaction is known as the first organic electrochemical reaction.It occurred as early as 1834 in electrolysis of carboxylic acid solutions to realize the free radical decarboxylation coupling process.Subsequently,direct anodic oxidation of C-H bonds-Shono oxidation reaction,showed the unique advantages of organic electrochemical synthesis: in the traditional redox reaction system,it is inevitable to add various exogenous redox agents,noble metal catalysts,etc.for the gain,loss and transfer of electrons,while organic electrochemistry can achieve this directly by gaining or losing electrons on the electrodes.Based on these,this thesis uses alkenes and alkynes as substrates to introduce various functional groups across the unsaturated bonds through electrochemical conditions.First,the synergistic effect of electrochemical conditions and diphenyl diselenide leads to the oxidative functionalization of alkynes to form α-ketoacetals.The introduction of carbonyl and bisalkoxy groups is realized at the same time.A selenonium species is supposed to function as the key intermediate of this reaction.Secondly,the alkene,water,and thiophenol are transformed to the thioether after tetrabutylammonium tribromide’s catalysis.Then,the sulfur atom is electrochemically oxidized to sulfoxide.Thus,a difunctionalization reaction of the alkenes is achieved.Finally,the difunctionalization of alkenes and the efficient and rapid construction of disulfides under non-metallic conditions are realized.The addition of diphenyl diselenide to olefinic double bonds mediated by tetrabutylammonium tribromide is achieved,where the selenonium intermediate plays a important role in this reaction.Fast and efficient synthesis of disulfide is realized under the mediation of tetrabutylammonium tribromide.The reaction has good reactivity in various organic solvent systems,and the work-up process is convenient.Wash with alkaline solution and extraction are enough to remove the by-products.This method is used to synthesiz not only a series of symmetric disulfide derivatives,but also asymmetric disulfide derivatives and thiosulfonates.