Study On Chiral Dirhodium(Ⅱ) Complexes Catalyzed Reaction Of α-diazo Carbonyl Compounds And Application For The Synthesis Of Chiral GABOB

In this thesis, we focused on the intramolecular C-H insertion reaction of N-(2-benzyloxyethyl)- N-(tert-butyl) diazoacetamide. The relationship between the activity of carbene and the influence factors, such as the type of catalyst, temperature, solvent was systematically studied. Through the extensively study, we found that the solvent can result in a major improvement in the enantioselectivity. Thereby, the chiral dirhodium(II) catalyst Rh2(4S-MEOX)4 and the solvent THF, which promoted the enantioselectivity intramolecular C-H insertion reaction of N-(2-benzyloxyethyl)- N-(tert-butyl) diazoacetamide with up to 91% e.e and 90% yield, consisted of the best catalytic system. Meanwhile, the utility of this method has been well examined in the synthesis of GABOB (? -amino-?? -hydroxybutyric acid). During hydrolysis of ? -lactam, both N-tert-butyl and O-benzyl groups were removed together with ring opening to give GABOB in one step. It is worth to mention that no obvious racemization occurs during the hydrolysis of ? -lactam and subsequently transformations.Chiral dirhodium(II) catalyzed intermolecular cyclopropanation reaction of ?-diazoacetate and styrene has also been studied.