H. Brunner, A. Knott, M. Kunz
Jul 1, 1986
Citations
0
Influential Citations
7
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract The Z - and E -isomers of the α- N -benzoylamino-2-butenoic acid methyl ester, the E/Z mixtures of α- N -benzoylamino-2-butenoic acid, and the Z -form of α- N -acetylamino-2-butenoic acid were hydrogenated enantioselectively. The hydrogenation products are derivatives of α-aminobutyric acid, which can be reduced to aminobutanol, the optically active component of the antituberculosis drug (+)-ethambutol. In situ catalysts consisting of [Rh(cod)Cl] 2 and the optically active phosphine ligands (+)- and (−)-Norphos, (+)-Prophos, (−)-Chiraphos, (−)-BPPFA, (−)-Diop, and (+)- and (−)-CpMn(CO) 2 diop were used. The best results were obtained with the substrate ( Z )-α-acetylamino-2-butenoic acid and the catalyst [Rh(cod)Cl] 2 /(−)-Norphos with 91.4% e.e.