Ring-opening Reactions Of Aziridines With Alkynals And Carboxylic Acids Catalyzed By Small Organic Molecule

Aziridines and their derivatives have attracted increasing attention of organic chemists as versatile building blocks for the synthesis of many nitrogen-containing biologically interesting molecules. In this thesis, we focus on ring-opening reactions of aziridines by two kinds of nucleophiles via organic small molecule.The ring-opening reactions of aziridines with alkynals catalyzed by N-heterocyclic carbine and the ring-opening reactions of aziridines with carboxylic acids catalyzed by DBU were described, respectively.Part I: Study on the ring-opening reactions of aziridines with alkynalsWe have successfully demonstrated the ring-opening reaction of aziridines with alkynals catalyzed by N-heterocyclic carbine precursor IXy·HCl. In this reaction, we did not get the expected pyridine derivatives by ammonia hydrogenation. Instead, the reaction afford the corresponding β-sulfonyl amino allyl esters in moderate yields.Part II: Study on the ring-opening reactions of aziridines with carboxylic acidsIn part two, the ring-opening reaction of aziridines with olefine acid, aromatic acid, fatty acid, acetylene acid catalyzed by DBU was studied in detail. We found that the reaction of aziridines with carboxylic acids catalyzed by organic base –DBU afford the corresponding β-sulfonyl amino esters. The advantages of this method include high yield, good substrate generality, metal-free conditions, and experimentally operational ease.