Zhang, YJ Kim, KY Park, JH Song, CE Lee, K Lah, MS Lee, SG 2024-01-21T05:14:51Z 2024-01-21T05:14:51Z 2022-01-10 2005-03 1615-4150 https://pubs.kist.re.kr/handle/201004/136672 The diastereomeric 1,4-diphosphine ligands, (S,S,S,S)-1a, (R,S,S,R)-1b and (R,S,S,S)-1c, with the imidazolidin-2-one backbone were synthesized, and utilized for an investigation of the effects of backbone chirality on the enantioselectivity in the Rh(I)-catalyzed hydrogenation of various functionalized olefinic substrates. It was found that the catalytic efficiencies are largely dependent on the configurations of the alpha-carbons to phosphine. Thus, the Rh complex of the pseudo-C-2-symmetrical diphosphine, (R,S,S,S)-1c, showed excellent enantioselectivities (93.0-98.6% ees) in the hydrogenations of a broad spectrum of substrates, and especially in the hydrogenations of methyl alpha-(N-acetyamino)-beta-arylacrylates (95.3-97.0% ees). However, the enantioselectivities obtained with the C-2-symmetrical (R,S,S,R)-1b were largely dependent on the substrate (19.8-97.3% ees). The Rh complex of ligand la having the (S,S,S,S)-configuration showed the lowest catalytic efficiency for all of the substrates examined (0-84.8% ees). English WILEY-V C H VERLAG GMBH HIGHLY ENANTIOSELECTIVE HYDROGENATION RHODIUM-CATALYZED HYDROGENATION AMINO ACID-DERIVATIVES 1,4-BISPHOSPHINE Synthesis of diastereomeric 1,4-diphosphine ligands bearing imidazolidin-2-one backbone and their application in Rh(I)-catalyzed asymmetric hydrogenation of functionalized olefins Article 10.1002/adsc.200404286 1 ADVANCED SYNTHESIS & CATALYSIS, v.347, no.4, pp.563 - 570 ADVANCED SYNTHESIS & CATALYSIS 347 4 563 570 scie scopus 000227764500011 2-s2.0-17144424244 Chemistry, Applied Chemistry, Organic Chemistry Article HIGHLY ENANTIOSELECTIVE HYDROGENATION RHODIUM-CATALYZED HYDROGENATION AMINO ACID-DERIVATIVES 1,4-BISPHOSPHINE asymmetric hydrogenation backbone chirality diphosphine ligands olefins rhodium