Studies On Lewis Acid-Catalyzed Asymmetric Ring-opening Reactions Of Aziridines With Amines

This thesis is focused on the development of catalytic asymmetric ring-opening reactions of aziridines which amines,which was outlined as below:After an initial screening of a range of experiment parameters,such as metal salts,chiral ligands,reaction solvents and temperature,the optimum reactions conditions were identified as follows: the combination of AgSbF₆ and?S?-DTBM-SEGPHOS as catalyst and m-xylene as solvent at ambient temperature.With this catalyst system,the ring-openings of both racemic 2-aryl aziridines via kinetic resolution and meso-aziridines via desymmetrization could be accomplished with various primary and secondary amines,with up to 99% yield and 97% ee.This reaction system features 100% atom-economy,broad substrate scope as well as mild reaction conditions,which makes a highly efficient way to diverse chiral vicinal diamine derivatives.Chiral vicinal diamines not only play an important role asymmetric catalytic chemistry as the core framework of many widely used chiral ligands or catalysts,but also occur in a number of naturally occurring or synthetic compounds with significant physiological activities.