Study On The Method Of Synthesizing Condensed-ring Aromatic Phosphine Salts By Electrochemical Oxidatio

Fused polycyclic phosphonium salts contain electron-deficient phosphorus center and large π-conjugated skeleton,it is an important organic compound in the research of functional materials.However,the researches on the synthesis of phosphonium salts are relatively limited,traditional synthesis methods are mainly based on thermochemical and photocatalytic pathways,often involving the use of transition metals or exogenous oxidants.This paper reviewed the research progress in related fields,and carried out related research work on synthesis of π-conjugated phosphonium salts by activation of trivalent phosphine substrate through C–H bond,specific research contents are as follows:(1)Organic electrochemical synthesis avoids toxic or dangerous oxidants,and uses electrons as a clean "reaction tool" to control the reaction process by adjusting the electrode potential.It is an efficient,simple and relatively green synthesis technology.The construction of C–X bond by C–H activation through electrochemical oxidation has become a hot topic in the field of organic synthesis.Based on electrochemical anodizing method,the first part of this paper realized the synthesis of a series of functionalized π-conjugated phosphonium salts in one step by electrochemical technology.This method does not require transition metals or additional oxidants,has good substrate universality,and can be used to prepare fused polycyclic phosphonium salts at gram level.It is an efficient and green method for synthesis of π-conjugated phosphonium salts.(2)Photoelectrochemical catalysis,which uses semiconductors as electrodes to realize the utilization of solar energy,has been developed in the fields of fuel production,pesticide degradation and water decomposition,etc.However,only few reports on this method in the field of organic molecules synthesis.In the second part of this paper,a method of photoelectrochemical catalytic synthesis of π-conjugated phosphonium salts was developed.The linear sweep voltammetry results showed that the addition of light reduced the initial potential of substrate oxidation,and achieved the power saving effect on the green and simple synthesis of π-conjugated phosphonium salts.Moreover,the photoelectric combination catalytic strategy to generate substituted fused polycyclic phosphonium salts has better substrate universality and functional group tolerance,and has high practical value.