Study On Lewis Acid-Catalyzed Dynamic Kinetic Asymmetric Transformations Of Racemic Aziridines With Ketene Silyl Acetals

This thesis mainly focuses on the development of Lewis acid-catalyzed dynamic kinetic asymmetric transformations reactions of racemic 2-（hetero）aryl-N-sulfonylazirdin-es with ketene silyl acetals,and the main content is as follows:After a screening of various chiral metal catalytic systems（metal salts and chiral ligands）and the optimization of reaction parameters such as reaction temperature and catalyst loading,the optimal reaction conditions for the catalytic asymmetric reaction were established as follows:[（CH₃CN）₄Cu]PF₆（5 mol%）,（S）-BINAP（6 mol%）in toluene at room temperature.Under these conditions,the scope of substrates（10-94%yield,68-97%ee）was studied and a series of chiralγ-aminobutyrate ester compounds were synthesized.Starting from the product 3ba,the anti-depression drug molecule（R）-rolipram was synthesized in high yield and enantioselectivity via a two-step reaction sequence.The newly synthesized compounds were characterized by modern characterization techniques such as NMR,HPLC and HRMS.