Research On Electrochemical Synthesis Of Sulfonamides And Aromatic Vinyl Sulfones

Sulfonamides and vinyl sulfones play an important role in the field of pharmaceutical research due to their versatile bioactivities.Up to now,kinds of methods for the synthesis of these two types of compounds have been reported.Nevertheless,it is still challenging for chemists to develop a novel,efficient,environmentally friendly,and practical synthetic method for the synthesis of these two types of compounds.This work is mainly focused on the electrochemical synthesis of sulfonamides and vinyl sulfones from dimethyl sulfoxide.(1)The study of sulfonamides synthesis via electrochemically promoting the coupling reaction of dimethyl sulfoxide and amines under the action of potassium iodide was made.Using the controlled variable method,the influence of different electrolytes,solvents,current levels,and electrode materials on the reaction was investigated.The investigation showed that dimethyl sulfoxide with primary and secondary amines could be used to preparing sulfonamides in good yields at room temperature when using potassium iodide as a conductive salt,a constant current of 30 m A,a platinum plate as an anode and a nickel plate as a cathode.In addition,the research showed that dimethyl sulfoxide was electrochemically oxidized and was attacked by iodine free radicals to form thiomethyl radicals.At the same time,hydrogens on the nitrogen of amines were attacked by iodine or dimethyl sulfoxide radicals to formed nitrogen radicals that coupled with thiomethyl radicals and oxidized by dimethyl sulfoxide to form sulfonamide compounds.This strategy has advantages of wide ranges of substrates,easy operation and environmental protection and so on.(2)Investigation on vinyl sulfones synthesis by electrochemically promoting the coupling reaction of dimethyl sulfoxide and olefins under the action of potassium iodide was performed.The dimethyl sulfoxide and alkenes could be converted into vinyl sulfones smoothly by electrochemical oxidation using potassium iodide as a conductive salt,dimethyl sulfoxide and water as a co-solvent.The research results showed that the target products of vinyl sulfones could be obtained when using aromatic olefins as raw materials,but when aliphatic olefins were used as raw materials,the reaction could not proceed.This study provides a novel,environmentally friendly and simple pathway for the synthesis of vinyl sulfones and the utilization of dimethyl sulfoxide.