Baker's yeast reduction of (E)-1-phenyl-1,2-propanedione 2-(O-methyloxime). A key step for a (−)-norephedrine synthesis
摘要:
The enantioselective Baker's yeast reduction of (E)-1-phenyl-1,2 propanedione 2-(O-methyloxime) 1 afforded (-)-(R)-1-hydroxy-1-phenyl-2-propanone 2-(O-methyloxime) 2 with 97% of enantiomeric excess (ee) which was diastereoselectively reduced by LiAlH4 to obtain the (-)-(R,S)-norephedrine with ee=82% and (-)-(R,R)-norpseudoephedrine with ee=93% in a ratio 4:1 respectively. (C) 1997 Elsevier Science Ltd.
Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines
作者:Josep Mas-Roselló、Tomas Smejkal、Nicolai Cramer
DOI:10.1126/science.abb2559
日期:2020.6.5
report that an iridium catalyst paired with a strong acid can hydrogenate C=N bonds without disturbing a weak N–O bond on the same nitrogen center. The reactions proceed at room temperature with high enantioselectivity. Science, this issue p. 1098 An iridium catalyst paired with an acid selectively reduces a C=Nbond while leaving an adjacent N–O bond intact. Asymmetric hydrogenations are among the most
Enantioselective bioreduction of ( E )-1-phenyl-1,2-alkanedione 2-( O- methyloxime)
作者:Olyr C Kreutz、Renata C.M Segura、J.Augusto R Rodrigues、Paulo J.S Moran
DOI:10.1016/s0957-4166(00)00163-4
日期:2000.6
The baker's yeast reduction of (E)-1-phenyI-1,2-alkanedione 2-(O-methyloxime), PhC(O)C(NOMe)R (R = Me, Et, n-Pr, n-Bu), gave the corresponding optically active alcohols PhCH2OHC(NOMe)R in 88-99% enantiomeric excess and 48-75% chemical yield. The R configuration was proposed for these alcohols based on circular dichroism analysis. Only the phenylglyoxal O-methylaldoxime (R=H) gave poor enantiomeric excess (65%) and chemical yield (14%). These compounds are potential chiral building blocks for the stereoselective synthesis of norephedrine analogs. (C) 2000 Elsevier Science Ltd. All rights reserved.
POLYMERS FUNCTIONALIZED WITH OXIME COMPOUNDS CONTAINING AN ACYL GROUP
申请人:Bridgestone Corporation
公开号:EP2649102B1
公开(公告)日:2014-11-26
US8748531B2
申请人:——
公开号:US8748531B2
公开(公告)日:2014-06-10
Baker's yeast reduction of (E)-1-phenyl-1,2-propanedione 2-(O-methyloxime). A key step for a (−)-norephedrine synthesis
作者:Olyr C. Kreutz、Paulo J.S. Moran、J.Augusto R. Rodrigues
DOI:10.1016/s0957-4166(97)00280-2
日期:1997.8
The enantioselective Baker's yeast reduction of (E)-1-phenyl-1,2 propanedione 2-(O-methyloxime) 1 afforded (-)-(R)-1-hydroxy-1-phenyl-2-propanone 2-(O-methyloxime) 2 with 97% of enantiomeric excess (ee) which was diastereoselectively reduced by LiAlH4 to obtain the (-)-(R,S)-norephedrine with ee=82% and (-)-(R,R)-norpseudoephedrine with ee=93% in a ratio 4:1 respectively. (C) 1997 Elsevier Science Ltd.