Cycloaddition Reaction Of Trifluoromethylated N-Acylhydrazones With Azomethine Ylides Or Maleimides

Nitrogen-containing heterocycles compounds have been found widespread applications in pharmaceuticals,agrochemicals and medicinal chemistry.It is particularly important to develop simple and efficient methods for synthesizing nitrogen-containing heterocycles.Azomethine imines,as a class of typical 1,3-dipoles,have been extensively used in 1,3-DC reactions to efficiently construct a variety of nitrogen-containing heterocyclic compounds.The trifluoromethylated N-acylhydrazones,as a new,acyclic and stable form of 1,3-dipoles,is mainly composed of trifluoromethyl group and N-acylhydrazone unit.Therefore,it is of great significance to use the trifluoromethylated N-acylhydrazones to synthesize nitrogen-containing heterocyclic rings containing trifluoromethyl groups and pharmaceutical molecules,agricultural chemical molecules and functional materials.This thesis is mainly composed of the following three parts: The chapter one: [3+2] Cycloaddition reaction of azomethine iminesThis chapter mainly reviews the different synthetic methods of various azomethine imines and the research progress of 1,3-dipolar cycloaddition reactions.The chapter two: [3+2] Cycloaddition of trifluoromethylated N-acylhydrazones with azomethine ylides: synthesis of trifluoromethylated imidazolidinesAn efficient [3+2] cycloaddition reaction of trifluoromethylated N-acylhydrazones with azomethine ylides has been developed under mild conditions,and a series of potentially bioactive trifluoromethylated imidazolidines were obtained in moderate to excellent yields.In this process,the trifluoromethylated N-acylhydrazones were used as trifluoromethyl building blocks,which provides a simple and effective new method for the synthesis of trifluoromethylated imidazolidines.The chapter three: [3+2] Cycloaddition of trifluoromethylated N-acylhydrazones with maleimides: synthesis of trifluoromethylated pyrrolopyrazolidinesThe [3+2] cycloaddition reaction of trifluoromethylated N-acylhydrazones with an electron-deficient olefin maleimides was explored under mild conditions,and a series of trifluoromethylated pyrrolopyrazolidines were obtained in excellent yields.