The Asymmetric Hydrogenation Of Protected Ethyl 1-(2-Aminoaceto)cyclopropanecarboxylates

In this thesis, we studied the asymmetric hydrogenation of protected ethyl 1-(2-aminoaceto)cyclopropanecarboxylates. After optimizing reaction conditions, we chose EtOH as the solvent, 70 oC as the temperature, [RuCl(benzene)(S)-SunPhos]Cl as the catalyst, which was synthesized with SunPhos and [Ru(benzene)Cl2]2. Highly effective asymmetric hydrogenation was realized and high enantioselectivities (up to 98.7% ee) were obtained. This asymmetric hydrogenation provides a key intermediate for the enantioselective synthesis of (S)-7-amino-5-azaspiro[2.4]heptane moiety of quinolone antibacterial agents. Because of its convenience, high efficiency and selectivity, this new synthetic method shows great significance and prospect in industrial applications.