Hydrogen Bonding Makes a Difference in the Rhodium-Catalyzed Enantioselective Hydrogenation Using Monodentate Phosphoramidites
作者:Yan Liu、Christian A. Sandoval、Yoshiki Yamaguchi、Xue Zhang、Zheng Wang、Koichi Kato、Kuiling Ding
DOI:10.1021/ja063350f
日期:2006.11.1
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%
Condensation of maleic anhydride or dimethyl maleate with benzylaldehydes controlled by tris(4‐anisyl)‐phosphine to synthesize dimethyl (E)‐2‐benzylidenesuccinates has been systematically investigated. The protocol gives the product with high stereoselectivity in moderate to good yields under mild conditions. A plausible mechanism has been proposed.