Electrochemical Promotion Of Oxidative Coupling Reactions Of Sulfur Radicals And Bifunctionalization Of Alkynes

Organic chemical synthesis provides many conveniences to human life and greatly enriches it materially.In conventional organic redox coupling reactions,the involvement of oxidising or reducing agents is usually required.In addition,the prefunctionalisation of raw materials and the multi-step post-treatment process inevitably generate an equivalent amount of chemical waste,which is not in line with the modern concept of green chemical synthesis in terms of both atomic and step economics.In the last few decades,electromechanical chemical synthesis has been favoured by researchers and has developed rapidly.Its use of electrons as traceless oxidising and reducing agents not only avoids the use of equivalent oxidising and reducing agents,but also enables efficient and highly selective conversion of substrates in many cases,making it a clean and efficient synthetic strategy.In this paper,we present a strategy for the synthesis of thiosulfates by electrochemical oxidation of sodium aryl sulfites with thiols to form aryl sulfonyl groups for oxidative cross-coupling with sulfur radicals to form S-S bonds.In addition,because trifluoromethyl compounds are important in biochemistry and medicine due to their ability to improve the lipid solubility,permeability and metabolic stability of molecules,as well as to promote drug absorption,distribution and donor-receptor interactions,this paper also reports the use of trifluoromethylation of alkynes under electrochemical conditions for the construction of heterocyclic compounds containing trifluoromethyl groups.The main results of the related studies were obtained as follows.1.the successful synthesis of various thiosulfinates with sodium aryl sulfites and thiols under electrochemical conditions without external oxidants and metal catalysts is reported,and the scale-up reaction was achieved in moderate yields,which has good potential for application and provides some basis for the subsequent application of the reaction.2.The one-step construction of bifunctionalised alkynes without the use of an external oxidant was reported for the first time under electrochemical conditions,and a series of trifluoromethylated vinyl heterocyclic compounds containing trifluoromethanes were synthesised using an inexpensive and readily available trifluoromethyl reagent(sodium trifluoromethanesulfinate),which has good substrate compatibility.