New Applications Of Sulfonates On The Synthesis Of Sulfonamides

Sulfonamides are ubiquitous in a wide range of natural products and pharmaceuticals,which have important applications in medicine,pesticides,dyes and organic synthesis.Therefore,much attention has been paid to the synthesis of sulfonamides owing to their attractive medicinal properties,and the development of new methods for the preparation of sulfonamides is highly desirable.However,the present synthetic methods suffer from certain disadvantages such as too complex operation,hazardous starting materials,harsh reaction conditions,long reaction time and most reactions usually use transition metals which seriously pollute the environment.This paper introduces some more efficient,economical,simpler and environmentally friendly methods for synthesis of sulfonamide compounds.1.Literature review.This chapter introduces the discovery and bioactivity of sulfonamide compounds,as well as the application of them in medicine and pesticide,especially focuses on their new synthesis methods and important reactions in organic synthesis.2.Iodine-catalyzed N-sulfonylation of benzotriazoles with sodium sulfinates.This chapter briefly introduces the application of elemental iodine as catalyst in organic synthesis.A convenient procedure is developed for the preparation of N-sulfonylbenzotriazoles from sodium sulfinates and benzotriazoles using molecular iodine as catalyst in air at room temperature,and a series of N-sulfonyl benzotriazole compounds are obtained.The feasibility and applicability of this method are verified by experiments,and the catalytic cycling mechanism is proposed.This catalytic radical sulfonylation proceeds efficiently under mild reaction conditions,which fits in the requirements of green chemistry and has practical application value.3.Sodium bromide promoted N-sulfonylation of benzotriazoles with sodium sulfinates.A novel protocol is developed for the preparation of N-sulfonylbenzotriazoles based on the above work: under neutral conditions at room temperature,the sulfonylation of benzotriazoles with sodium sulfinates promoted by sodium bromide in the present of m-chloroperbenzoic acid(mCPBA)proceeds efficiently in EtOAc/MeOH(4:1),resulting in the corresponding products with good yields.The reaction conditions are optimized,various substrates are evaluated,and a possible reaction mechanism is also hypothesized.4.One-pot synthesis of sulfonamides from sodium sulfinates and amines via sulfonyl bromides.Through a series of reactions,a new nucleophilic substitution reaction of sodium sulfinates and amines is reported for preparation of sulfonamides,which is promoted by tetrabutyl ammonium bromide in the present of oxidant mCPBA.This S-N bond formation reaction proceeds efficiently via sulfonyl bromides under neutral conditions,to afford the corresponding sulfonamides in good yields at room temperature.The reaction conditions are optimized,various substrates are evaluated,and a possible reaction mechanism is proposed.