Study On Synthesis Of Sulfone By Electrochemical Oxidation And Synthesis Of Sulfoxide And Sulfone By Selective Oxidation

Sulfone compounds exist in many drug molecules and are widely used in the fields of medicine,plastics and organic synthesis.Therefore,the synthesis of sulfone compounds has attracted the attention of many chemists.The commonly used methods for synthesizing sulfones are direct oxidation of thioethers,coupling reactions of sulfinates.In the previous reports,these methods inevitably use stoichiometric oxidants or require harsh reaction conditions and are not friendly to the environment.The traditional methods for generating sulfonyl radicals also require the use of initiators or oxidants,which cannot get rid of the shortcomings of traditional organic synthesis processes.Therefore,developing an efficient,mild,and environmentally friendly method for synthesizing sulfone compounds has positive significance in many research fields.In recent years,electrochemical oxidative cross-coupling has attracted more and more attention.It has become an important method to construct a variety of complex organic molecules due to its advantages of no external oxidant and no pollution to the environment.We took advantage of electrochemical organic synthesis methods to realize the C3 sulfonylation of imidazopyridines.Compared with the cross-coupling reaction,the direct oxidation of sulfides is undoubtedly a more direct and economical method for the formation of sulfones.However,these reported methods are usually accompanied by harsh reaction conditions,poor chemical selectivity,over-oxidation and environmental pollution problems.Therefore,we also realized the selective oxidation of thioether by methanol to obtain sulfone and sulfoxide under electrochemical conditions.The relevant research results are as follows:1.Through the literature survey of sulfones,we take advantage of the "safe and green" advantages of electrochemistry.Using sodium sulfinate as the source of sulfonyl radicals,the C3 sulfonylation of imidazopyridines was investigated.A series of sulfonylated products were prepared under the conditions of no metal,no external oxidant and additives,and all of them had good substrate compatibility and yield.2.Through the investigation of relevant literatures on the oxidation of sulfide to obtain sulfone and sulfoxide,we directly oxidized sulfide to obtain the products of sulfoxide and sulfone under electrochemical conditions.The clean energy "water" used in this reaction is used as the oxygen source,and the products of sulfone and sulfoxide can be selectively obtained by methanol.