Construction Of Five-membered Heterocyclic Derivatives By [3+2] Cycloaddition Reactions Between 1,3-dipoles And Aldehydes

Over the last decade,1,3-dipolar cycloaddition reaction has opened a new avenue for the synthesis of target heterocyclic molecules.For instance,it has been reported that 1,3-dipolar cycloaddition reactions between aza-oxyallyl cationic and indole to construct a novel N-heterocyclic compounds.There are many advantages of this reaction,such as a short reaction time and mild reaction conditions.It is also reported the 1,3-dipolar cycloaddition reactions between azomethine imines and enals which can efficiently construct chiral heterocyclic compounds.This thesis mainly focues on the investigation of construction of five-membered heterocyclic derivatives by [3+2] cycloaddition reactions between 1,3-dipoles and aldehydes.In this thesis,the research work is divided into three chapters.Firstly,a brief introduction on the the development of 1,3-dipolar [3+2],[3+3],[3+4] cycloaddition reaction is presented in chapter 1.Chapter 2 describes cycloaddition reactions of ?-halohydroxamate with unsaturated aldehydes affording oxazolidin-4-one compound mediated by inorganic base.Chapter 3 presents chiral N-heterocyclic carbene [3+2] cycloaddition reactions of 1,3-dipolar azoimines with ?-haloaldehydes,affording chiral bicyclic pyrazolidinone compounds.