Single Electron Transfer Reactions Realized By Organic Photo-and Electro-synthesis

Organic photosynthesis and organic electrosynthesis,as two major synthetic methods in organic synthesis,have greatly promoted the development of organic synthetic chemistry.Organic photochemical synthesis utilizes photocatalysts to form excited states under illumination,and chemical reactions occur through electrons transfer,energy transfer or hydrogen atom transfer.Organic electrochemical synthesis proceeds through the oxidation or reduction of reactants or catalysts by electron tranfer on electrodes.In essence,both photochemical and electrochemical syntheses are based on single electron transfer.This dissert mainly studies the single electron transfer reaction under electrocatalytic and photocatalytic conditions.The specific studies are as follows:1.Electrochemical catalytic cyanation of indole derivatives:Using indole as substrate,in an undivided cell equipped with a RVC anode and platinum cathode,tris(4-bromoaniline)amine as catalyst,Na OH as base,acetonitrile and water as solvent,tetrabutyltetrafluoroboric acid Ammonium(n Bu₄NBF₄)as electrolyte,nitrogen atmosphere,reacted with cheap and readily available trimethylcyanosilane under constant current(10 m A)conditions for 2.5 hours to realize the cyanation of indole.The reaction has the characteristics of mild conditions,simple operation and a wide range of substrates.2.Photocatalytic bis-substituted tetrahydrofuran derivatives synthesis:Using quinoxalin-2(1H)-one,2,3-dihydrofuran,tert-butyl hydroperoxide as substrates,DCE as solvent,TPPT as photocatalyst,visible light blue LEDs(450–455 nm)for 2 h,the disubstituted tetrahydrofuran derivatives were obtained in good yields.3.Electrochemical dearomatizing spirocyclization to generate spiro[4.5]deca-trienones:Using alkynes and 2-benzylmalonates as substrate,in an undivided cell equipped with a RVC anode and Platinum cathode,Methanol and Tetrahydrofuran as solvent,Ferrocene as catalyst,Scandium(III)trifluoromethanesulfonate as additive,Na₂CO₃ as base,Tetrabutyltetrafluoroboric acid ammonium as electrolyte.The electrolysis was carried out at 65 ^oC using a constant current of 10 m A for 2.5 h,providing the corresponding products in good yields.