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Deschenaux, Robert
Résultat de la recherche
Stereoselectivity in reactions of metal complexes. VIII. Asymmetric synthesis of some amino acids by stereoselective transamination of aliphatic keto acids in mixed ligand copper(II)-Schiff-base complexes
1984, Deschenaux, Robert, Bernauer, Klaus
Optically active alanine, valine and leucine were obtained by a transamination reaction between pyridoxamine and the corresponding ?-keto acid in the presence of a Cu2+-complex with the tridentate ligand 2,6-bis[(3S)-3-phenyl-2-azabutyl]pyridine. In each case the amino acid with (R)-configuration was formed preferentially, and the max. enantiomeric excesses were 54% (alanine), 48% (leucine) and 29% (valine). The stereoselectivity of the reaction is discussed in terms of the possible structure and the stability of the intermediate Cu2+-ketimine-ligand complex. [on SciFinder(R)]
Stereoselectivity in reactions of metal complexes. VII. Asymmetric synthesis of amino acids by metal ion-promoted transamination
1983, Bernauer, Klaus, Deschenaux, Robert, Taura, Toshiaki
Enantioselective synthesis of phenylalanine was performed by reacting phenylpyruvic acid with pyridoxamine followed by ketimine-aldimine isomerization of the resulting Schiff base catalyzed by an optically active copper(II)-complex. UV and CD measurements showed that the enantiomeric excess strongly depends on the reaction conditions and on the reaction time and in favorable cases it reacted values of 80%. The selectivity of the reaction is discussed on the basis of possible structures of the intermediate mixed ligand complex. [on SciFinder(R)]