Enantioselective synthesis of both enantiomers of phosphinothricin via asymmetric hydrogenation of .alpha.-acylamido acrylates
摘要:
Both enantiomers of phosphinothricin (1), a naturally occuring amino acid that contains the unique methylphosphinate moiety, were prepared by asymmetric hydrogenation of alpha-acylamido acrylate precursors 7. L-1 and peptides containing L-1 are inhibitors of the enzyme glutamine synthetase (GS). Inhibition of GS is responsible for the antibiotical and herbicidal properties of these compounds. Synthesis of substrates 7 and parameters influencing the enantioselectivity are discussed. Substrate concentration and solvent polarity appear to have the most marked effects on enantiomeric excesses for a given catalyst system. Enantiomeric excesses reach 91 % for hydrogenations with (R,R)-NORPHOS- and (S,S)-CHIRAPHOS-derived catalysts.
Process for producing phosphorus-containing dehydroamino acid
申请人:Meji Seika Kaisha Ltd.
公开号:US08329935B2
公开(公告)日:2012-12-11
A process for efficiently producing through a small number of steps an N-substituted 2-amino-4-(substituted-oxymethylphosphinyl)-2-butenoic ester which is an intermediate for herbicide L-AMPB. The process comprises reacting a compound represented by the following formula (1): (where R1 represents C1-4 alkyl group) with a compound represented by the following formula (2): (wherein R2, R2′, and R3 each represents C1-4 alkyl and R4 represents benzyloxycarbonyl) in the presence of a base.