Electrochemical Generation Of Sulfonyl Radical And Its Application In Organic Synthesis

Sulfonamide drugs exhibit extensive biological activities and are widely used in clinical research.They have the unique characteristics,such as anti-bacteria,anti-viral,anti-tumor,anti-fungal.Oxindoles are an important structural motif and widely exist in natural products with biological activities and drugs with pharmacological activities.It is of great significance for the research and development of drug library through the introductory of sulfonyl to the C-3 position of oxindoles.It is important to develop a simple and environmentally friendly method for the synthesis of sulfonamide compounds and sulfonyl substituted oxindoles.In this paper,sulfonyl radical,which is induced by the use of halogen under electrochemical conditions,is applied to synthesize the sulfonamides and sulfonyl substituted oxindoles.The paper conducted the following research:(1)Electrochemical synthesis of sulfonamidesA novel,green and efficient method for electrochemical synthesis of sulfonamides was established.This method is carried out in an undivided cell and a catalytic amount of halogen is not only a redox catalyst but also a supporting electrolyte.A series of sulfonamides are synthesized by the reaction of sulfonyl radical and amines.The generation of sulfonyl radical is induced by the halogen from the sodium sulfonate,which has the advantages of non-toxic and readily available.The experiment of scale up shows that this method has a potential application value.The method has the advantages of high efficiency,green,safety and simple operation,and avoids the use of metal catalyst and stoichiometric oxidants.(2)Electrochemical synthesis of sulfonyl substituted oxindolesA novel,green and efficient method for electrochemical synthesis of sulfonyl substituted oxindoles was established.This method is carried out in an undivided cell and a catalytic amount of halogen is a redox catalyst.A series of sulfonyl substituted oxindoles are synthesized by the reaction of sulfonyl radical and methylacrylamide.The generation of sulfonyl radical is induced by the halogen from the sodium sulfonate,which has the advantages of non-toxic and readily available.The experiments of onepot,two-step synthesis of oxindoles and scale up show the potential application value.The method has the advantages of high efficiency,green,safety and simple operation,and avoids the use of metal catalyst and stoichiometric oxidants.