Hydrogen bonding makes a difference in the rhodium-catalyzed enantioselective hydrogenation using monodentate phosphoramidites.
A new generation of monodentate phosphoramidite ligands bearing a primary amine moiety was found to display comparable or better efficiency than bisphosphines in the Rh-catalyzed asymmetric hydrogenation of challenging substrates, such as (Z)-methyl alpha-acetoxyacrylate or (E)-beta-aryl itaconate derivatives, affording the corresponding hydrogenation products with excellent enantioselectivities (up to >99% ee). The presence of intermolecular hydrogen bonding (HB) between two monodentate ligands in the catalyst was found to be critical for excellent catalyst performance. This finding provides a basis for design and development of further catalyst systems using this type of monodentate phosphoramidite ligands.
Liu
Yan
Y
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry (SIOC), Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, PR China.
Sandoval
Christian A
CA
Yamaguchi
Yoshiki
Y
Zhang
Xue
X
Wang
Zheng
Z
Kato
Koichi
K
Ding
Kuiling
K
D002384:Catalysis; D006860:Hydrogen Bonding; D006865:Hydrogenation; D008024:Ligands; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
D008024:Ligands; D009943:Organophosphorus Compounds; C434331:phosphoramidite; D012238:Rhodium