American Chemical Society
jo300867y_si_002.pdf (3.67 MB)

Stereoselective Synthesis of Norephedrine and Norpseudoephedrine by Using Asymmetric Transfer Hydrogenation Accompanied by Dynamic Kinetic Resolution

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journal contribution
posted on 2012-06-15, 00:00 authored by Hyeon-Kyu Lee, Soyeong Kang, Eun Bok Choi
Each of the enantiomers of both norephedrine and norpseudoephedrine were stereoselectively prepared from the common, prochiral cyclic sulfamidate imine of racemic 1-hydroxy-1-phenyl-propan-2-one by employing asymmetric transfer hydrogenation (ATH) catalyzed by the well-defined chiral Rh-complexes, (S,S)- or (R,R)-Cp*RhCl­(TsDPEN), and HCO2H/Et3N as the hydrogen source. The ATH processes are carried out under mild conditions (rt, 15 min) and are accompanied by dynamic kinetic resolution.