Application Of Long Range Pummerer Reaction In Organic Synthesis

Sulfoxides as an important class of organic sulfur compounds,have a wide range of applications in the synthesis of drug molecules,biologically active molecules,complex natural products,and multifunctional materials.As one of the most representative reaction of sulfoxide compounds,the Pummerer reaction has attracted an increasing attention due to its high reactivity and good stereoselectivity.The sulphonium ion intermediates in the Pummerer reaction can be attacked by a variety of different nucleophiles in an intermolecular and intramolecular fashion,which represents a convenient and practical method for divergent synthesis of organic molecules with complexed strutures.This dissertation mainly studies synthetic applications of Pummerer reaction.The details are as follows:1.Pummere reaction constructs functionalization of Ortho-C(sp2)-H bonds of aniline derivatives.A new strategy for remotely controlling the functionalization of C(sp2)-H bonds in aryl rings by aryl Pummere reaction is proposed.The reaction process mainly includes:treated with acid anhydride,sulfoxide forms the thionium ion intermediate.Nucleophile then attacks the thionine intermediate,followed by the aromatization to provide final products.The method is operation-simple,rection condition-mild,and provides an alternative towards the construction of polyfunctional aniline.Halogenated product can be also structurally elaborated into other many versatile molecules.2.Aryl Pummere reaction remote control functionalization of C(sp3)-H bonds.A new strategy to remotely control the functionalization of aromatic ring C(sp3)-H bond via aryl Pummere reaction is proposed.In this reaction,the sulfoxide is activated by trifluoroacetic anhydride(TFAA),and the remote alpha proton of the aromatic benzylic group is eliminated to form a thionium intermediate.After being captured by different nucleophiles,the electron transfer is completed,and the aromatic ring benzyl is different.Functional group substituted aryl compounds are obtained.Benzyl halides can be used as precursors for the conversion of different functional groups,which provides a new way for the construction of organic molecules.3.Indole Pummerer reaction:dearomatization/different functionalization of C(sp2)-H bond in C-2 positionA novel reaction for the dearomatization of the indoIe/C(sp2)-H bond functionalization is achieved via the Pummere reaction.The method is operation-simple,rection condition-mild and the yield satisfactory.It is convenient to construct multi-functionalized fluorene skeletons,which has a certain practical application value.