35144-07-1Relevant academic research and scientific papers
Asymmetric Catalyses. V. Enantioselective Amino Acid Synthesis by Hydrogenation of Prochiral Olefins with Rh-Complexes of the New Optically Active Chelating Phosphane Norphos
Brunner, Henri,Pieronczyk, Willigis,Schoenhammer, Beate,Streng, Karin,Bernal, Ivan,Korp, Jim
, p. 1137 - 1149 (2007/10/02)
Racemic bicyclohept-5-ene-2,3-diylbis(diphenylphosphane oxide), NorphosO, can be resolved with (-)-di-O-benzoyltartaric acid, (-)-DBW.The X-ray structure analysis of the diastereomer (-)-NorphosO/(-)-DBW, which is less soluble in ethanol, exhibits strong hydrogen bonds between the carboxylic groups of DBW and the PO groups.The bonding of the DBW-carboxylic groups to different NorphosO units leads to the formation of infinite close-packed chains.From the internal comparison with (-)-DBW the absolute configuration follows as (2R,3R) for (-)-Norphos.The chelating phosphanes (+)- and (-)-Norphos, obtained by SiHCl3-reduction of (+)- and (-)-NorphosO, respectively, afford neutral and cationic Rh-complexes which, with H2 at room temperature and atmospheric pressure within a few hours, give quantitative hydrogenation of α-(acetylamino)cinnamic acid, α-(acetylamino)acrylic acid and Dopa precursors.The optical yields vary between 79 and 97percent.
