The Asymmetric Synthesis Of Fluorinated Amines Induced By (S)-Tert-Butanesulfinamide

Because of fluorinated compounds have been widely used in the field of bio-pesticides and pharmaceuticals, the development of method for introducing of fluorine-containing group into organic molecule has become a hot research topic in organic chemistry. This thesis studied the asymmetric synthesis of difluoromethylated aziridines, and explored the asymmetric addition reaction of a-trifluoromethyl aldimine with Schiff base.Part I:(S)-N-tert-butanesulfinyl ketimines were synthesized with (S)-N-tert-butanesulfinamide and CF2-substituted aldehydes (ketones) via dehydration condensation catalyzed by Lewis acid Ti(O’Pr)4. And then the asymmetric addition reaction of sulfur ylide to these ketimines to form a-difluoromethylated aziridine was investigated. The desired aziridines can be obtained in yield of46-88%after optimization of reaction conditions including solvents, temperature and reaction time. The diastereoselectivity is depended on the structure of ketimines, the highest dr value for arylketimines is62:38, but it can reach to>99:1for alkynyl ketimines.Part II:Firstly,(S)-N-tert-butanesulfinamide and CF3-substituted aldehydes was condensed to form imines. And then the asymmetric addition reaction of the resulting imine with Schiff base under different conditions was explored. Unfortunately, no pure desired addition product can be isolated after several attempts.