Study On Asymmetric Alkylation Reactions Of 2,5-Diketopiperazines Catalyzed By Aza-Spirocyclic Triazolium

Piperazine and its derivatives are the core skeletons of many natural products and drug molecules,among which chiral 2,5-Diketopiperazines derivatives(2,5-DKPs)usually show excellent biological activities.However,the separation of active natural products is difficult due to limited sources and the lack of catalytic asymmetric synthesis strategies seriously hinder its application and development.Based on this,as an important extension of the spirocyclic amide triazolium phase transfer catalyst developed in our group for the asymmetric reaction,we design and implement the direct single or double asymmetric alkylation reaction of α-ester substituted 2,5-DKP,and efficiently constructed a series of 2,5-DKPs containing single or double quaternary carbon.This paper is divided into the following three chapters:Chapter 1: Some active natural products of 2,5-DKP and their synthesis methods are listed.The synthesis methods of 2,5-DKPs are summarized in three sections: 1)Synthesis from chiral α-amino acids or their derivatives;2)Functionalization of chiral2,5-DKPs;3)Catalytic asymmetric transformation.Chapter 2: The research progress of spirocyclic amide catalysts developed by our group,is introduced in brief;The exploration,optimization and expansion of asymmetric alkylation reactions of α-ester substituted 2,5-DKP with our catalysts.In addition,the intramolecular hydroarylation reactions of 2,5-DKPs was preliminarily investigated based on the ligands developed by our group.Chapter 3: Experimental operation and characterization data of related compounds.