Study On Copper Catalyzed/Promoted Synthesis Of Pyrazolines

Pyrazoline derivatives,An important class of functional organic molecules and significant biological activities,are widely used in many fields,such as medical drugs,pesticides,fluorescent brightener,fluorescent probes,and luminescent materials,so the search for safe,easy and efficient methods of constructing pyrazoline derivatives has gained considerable attention from the synthetic community.Up to date,there have been many methods for synthesizing pyrazoline compounds.New synthetic methods have been continuously developed,and conventional synthetic methods have been continuously improved.In this paper,During the experiment,we optimized the reaction conditions and selected the optimal reaction conditions,examining the applicability of the substrate under the optimal conditions.Our group have developed a new method of constructing functionalized pyrazoline derivatives by using copper salts and ?,?-unsaturated hydrazones,and successively achieved azidation and halogenation(iodination,bromination,chlorination),thiocyanation,sulfurization and selenization of pyrazoline derivatives.At the same time,we also carried out the relevant verification experiments of the mechanism and proposed a reasonable reaction mechanism.This thesis is divided into four chapters according to my work.The main contents are as follows: In chapter 1,our mainly introduce the structural properties of pyrazolines,the application of pyrazolines in various fields and the common strategies of Synthesis pyrazolines.Chapter 2: we have synthesized a series of azided pyrazolines by copper salt promoting aminoazidation of ?,?-unsaturated hydrazones.This strategy offers rapid access to a broad spectrum of azided pyrazolines through tandem N-C/C-N bond formation,in good yields with nice functional group compatibility.In chapter 3,we have synthesized a series of halogenated/thiocyanated pyrazolines via copper salt promoting aminohalogenation/ thiocyanation of ?,?-unsaturated hydrazones.In addition,this type of core is also a valuable unit in the fields of organic synthesis and medicine.This novel strategy greatly increases the possibility of further reaction of the pyrazolines.In Chapter 4,A convenient copper-catalyzed sulfeno-/selenoamination of ?,?-unsaturated hydrazones with disulfides/diselenides via radical pathway has been developed.The protocol enables efficient access to various sulfenylated/selenylated pyrazolines under mild reaction conditions and no extra oxidant is required.It is noticeable that the reaction can be smoothly carried out when it was scaled up to the gram scale.