search for green chemistry methods for the enantioselective reduction of ketoesters Saccharomyces cerevisiae- and ruthenium-catalyzed reactions in water have been investigated. The highest enantiomeric excesses for the reduction of α- and β-ketoesters have been obtained by S. cerevisiae. Chiral ruthenium catalysts are active for the reduction of all ketoesters with low to moderate enantioselectivities
Sterically Hindered Chiral Ferrocenyl P,N,N-Ligands for Highly Diastereo-/Enantioselective Ir-Catalyzed Hydrogenation of α-Alkyl-β-ketoesters via Dynamic Kinetic Resolution
作者:Chuan-Jin Hou、Xiang-Ping Hu
DOI:10.1021/acs.orglett.6b02828
日期:2016.11.4
A new class of sterically hindered chiral ferrocenyl P,N,N-ligands have been prepared through a two-step transformation from (Sc,Rp)-PPFNH2, in which a new (R)-stereogenic center at the pyridinylmethyl position was generated in high diastereoselectivity. With these newly developed P,N,N-ligands, Ir-catalyzed asymmetric hydrogenation of various α-alkyl-substituted β-aryl-β-ketoesters via dynamic kinetic
Use of 1,3-oxazolidin-2-one derivatives of 3-borylpropenoic acids as β-hydroxy acrylic acid equivalents in the asymmetric Diels-Alder reaction catalyzed by a chiral titanium reagent
作者:Koichi Narasaka、Ichiro Yamamoto
DOI:10.1016/0040-4020(92)80025-b
日期:1992.7
Catalytic asymmetric Diels-Alder reaction was developed by employing 3-(3-boryl-propenoyl)-1,3-oxazolidin-2-one as a β-hydroxyacrylic acid equivalent. With a catalytic amount of the titanium reagent, 3-(3-borylpropenoyl)-1,3-oxazolidin-2-ones react smoothly with various dienes in the presence of Molecular Sieves 4A to afford the adducts in high yield with high optical purity. Boryl groups of the adducts