One Pot Stereoselective Construction Of Novel Aziridine Derivatives

Aziridines,an important class of three-membered azaheterocycles,have been widely used in organic chemistry.Furthermore,the aziridine skeleton are present in many natural products and compounds of pharmaceutical significance.Thus,the construction of these three-membered ring motifs has been an active research area in organic synthesis and drug chemistry.Traditionally,the main approaches to the construction of aziridines include the nitrogen-olefin additions,the carbon-imine cyclizations,aziridinations via intramolecular substitution and the azirine transformations.Despite these impressive advances,the development of new synthetic treansformations for the efficient construction of diverse aziridines is still in great demand.In this thesis,we developed a novel one-pot sequential transformation,using potassium iodide as catalyst and tert-butyl hydroperoxide as oxidant,via Mannich reaction and oxidative C-H amination of cyclic imines with ?-ketoacids.By optimizing the reaction conditions,the aziridine derivatives were synthesized in moderate to high yields(46 – 78%)and excellent diastereoselectivities.In addition,chiral aziridine derivatives have been synthesized in the presence of the copper complexes of chiral bisoxazoline ligands.A series of products were obtained with moderate to high yields(46 – 81%)and good enantioselectivities(80 – 87%).Finally,the highly optically pure isomer(ee > 99.9%)was obtained,and its absolute conformation was confirmed by X-ray single crystal diffraction analysis.