| Because of its universal biological activities,sulfonamides have been widely applied in the fields of medicine and pesticides.On one hand,sulfonamides are used in medicine as antiseptic,anti-inflammatory,anti-tumor and anti-HIV agents.On the other hand,Sulfonamides can be used as pesticides,weeding and insecticides.In general,sulfonamides can be prepared by nucleophilic reaction of sulfonyl chlorides with primary or secondary amines.Complementarily,sulfonamides could also be prepared via methods such as: transition metal catalyzed oxidative amination of mercaptans,transition metal catalyzed cross-coupling of secondary sulfonamides and halogenated hydrocarbons,hydrocarbons,and alcohols.In addition,sulfonic acid,sodium sulfinate,sulfonyl hydrazide could be employed as raw material to react with amines,producing a variety of sulfonamides.Since many sulfonamide synthetic methods employ transition metal catalysts which in general are expensive and may cause serious environmental pollution in large scale synthesis.In recent years,chemists want to explore some facile,efficient and greener methods to prepare these privileged compounds.In this thesis we provide a novel transition metal-free appraoach for the synthesis of sulfonamide compounds.This thesis consists of four chapters:Chapter 1: Review on carbon-nitrogen bond cleavage reaction of aminesThis chapter mainly introduces the research progress on the C-N bond cleavage and activation of amine compounds.Carbon-nitrogen bond is a kind of chemical bond commonly found in nature.Due to the high dissociation energy,carbon-nitrogen bonds cleavage has become one of the most challenging research topic in chemical synthesis.By C-N bond cleavage,amines could serve as excellent carbon sources and nitrogen,thus,C-N biond activation has become a hot area in organic chemistry.Chapter 2: Study on the Reaction of Sulfonyl Chlorides with ?-or ?-Func-tionalized Tertiary AminesThis chapter mainly studies the reaction of sulfonyl chlorides with ?-or?-functionalized tertiary amines.The ?-functionalized tertiary amines refer to tertiary amines whose ? position has a nitrogen atom,i.e.,tetrasubstituted ethylenediamines.The ?-functionalized tertiary amine here refers to a tertiary amine having a functional group at the ?-position,e.g.,N-methyl-4-hydroxypiperidine,N-methyl-4-piperidone and so on.Interestingly,reaction of sulfonyl chloride and 4-hydroxy-Nmethylpiperidine undergo a ring-opening and thus expel a molecule of formaldehyde to generate a N-methyl-N-(3-butenyl)tertiary sulfonamide.The yield varied from medium to excellent.Sulfonyl chloride and N-methylpiperidin-4-one also undergo ring-opening reactions,resulting in the formation of unsaturated ketone compounds.However,since the product contains an unsaturated keto groups,this product can easily undergo further Micheal addition reaction with the amine.Chapter 3: Study on the Reaction of Sulfonyl Chlorides with Triethyl-enediaminesThis chapter mainly studies a new method for the synthesis of piperazine compounds by reaction of various functionalized sulfonyl chlorides with DABCO.The obtained 1-(2-chloroethyl)-4-sulfonylpiperazine could further be functionalized with various sodium alkoxides,Sodium acetate,sodium phenoxide,sodium benzoate,sodium thiophenolate and a variety of secondary amines,e.g.,N-methylaniline,p-methyl-N-methylaniline,p-fluoro-N-methylaniline etc.,to prepare more functionalized sulfonyl piperazine derivatives.Chapter 4: Reductive Coupling Reaction of Sulfonyl Chlorides with OrganohalidesThis chapter mainly discuss the reductive coupling reactions of aryl sulfonyl chlorides with alkyl sulfonyl chlorides.Under ultrasonication,sulfonyl chlorides are reduced by magnesium metal to produce the magenisium sulfinates,further reaction with various chlorinated hydrocarbons or brominated hydrocarbons to yield the corresponding sulfones in high yields.This two-step,one-pot new synthetic method has advantages of high yield,good chemoselectivity,simple operation and wide range of functional groups tolerance. |
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