Studies On Copper-Catalyzed Synthesis Of Thioesters Via Cross-coupling Of Aryl Hydrazides

Thioester compounds are an important class of intermediates in organic synthesis and acylation reactions.They are widely found in natural products,pharmaceutical intermediates,and pesticides.Traditionally,thioester compounds were synthesized by the cross-coupling of benzoyl chlorides with sulfhydryl compounds.In view of the hygroscopicity and instability of benzoyl chloride,a green,efficient,and economic method for constructing thioesters was highly required.The benzoyl hydrazide compound has many advantages over other carboxylic acid derivatives,such as stable properties,easy availability,and no special odor.In this thesis,the research work of copper-catalyzed reaction of aryl hydrazide with disulfide or thiol/thiophenol for the synthesis of thioester compounds was carried out with the research of "simple and efficient preparation of thioester compounds".The specific contents and research results are as follows:(1)A new method for the synthesis of thioesters has been developed by using aryl hydrazide compounds and disulfides as starting materials.This method using low-cost and readily available ammonium persulfate as oxidant and cuprous cyanide as catalyst to realize efficient synthesis of thioesters without adding any acid,base and ligand.The method is novel,simple with good functional group tolerance and substrate scope,which provides a new way for the synthesis of thioesters.(2)A simple and efficient method for the synthesis of thioesters via copper-catalyzed coupling of aryl hydrazides has been developed.This method using thiol/thiophenol as sulfur source,cheap and easily available ammonium persulfate as oxidant,cuprous cyanide as catalyst,DMSO as solvent,which can realize efficient synthesis of thioesters under acid/base and ligand-free conditions.