Study On The Application Of Donor-Acceptor Aziridines In The Synthesis Of Chiral Carbohydrate-spiro-heterocycles

As a versatile synthetic block,donor-acceptor aziridines have been widely used in the synthesis of nitrogen-containing heterocyclic compounds.Firstly,the cyclization of D-A aziridines with chiral exo-glycals catalyzed by Lewis acid was investigated,and its application in the synthesis of chiral carbohydrate-spiro-heterocycles was also studied.In addition,we have studied the cyclization reaction of quinone monoimine and vinyl azide,and the new synthesis method of benzofuran derivatives was explored preliminarily.The research contents are divided into the following three parts:Chapter 1:Research progress of related reactions of D-A aziridinesThis chapter reviews the research progress of ring-opening and cyclization reactions involving D-A aziridines.As a highly strained cyclic amine,aziridines can easily undergo C–N bond cleavage,but when an electron-withdrawing substituent is attached to the carbon atom of the aziridine,lower reaction energy barrier for the break of the C-C bond.Such as D-A aziridines,which can promote the activation of the C-C bond under Lewis acid catalysis,and the ring opening or cyclization reaction can occur under mild conditions.Chapter 2:Synthesis of chiral carbohydrate-spiro-heterocyclesIn this chapter,the synthesis of chiral carbohydrate-spiro-heterocycles from chiral exo-glycals is introduced firstly.On this basis,we developed a new method for the synthesis of chiral carbohydrate-spiro-heterocycles,the[3+2]-cyclization of D-A aziridines with chiral exo-glycals catalyzed by Lewis acid,to achieve the synthesis of chiral 1-oxa-7-azaspiro[4.4]nonane and 2-aza-6-oxaspiro[4.5]decane derivatives.At the same time,this method can be directly used for nucleoside modification.Chapter 3:Research on the[3+2]-cyclization reaction of quinone monoimines and vinyl azide catalyzed by HNTf₂In this chapter,we first introduced the research progress of vinyl azide in nearly three years.Then,a new method for the synthesis of 2,5-disubstituted benzofuran without metal catalysis was developed,the cyclization reaction of vinyl azide with electrophilic quinone imine was catalyzed by HNTf₂.