Asymmetric Hydrogenation of α,β-Unsaturated Carboxylic Acids Catalyzed by Ruthenium(II) Complexes of Spirobifluorene Diphosphine (SFDP) Ligands
作者:Xu Cheng、Jian-Hua Xie、Sheng Li、Qi-Lin Zhou
DOI:10.1002/adsc.200606065
日期:2006.7
The ruthenium diacetate complexes ligated by chiral spirobifluorene diphosphines (SFDP) were very effective catalysts for the asymmetric hydrogenation of tiglic acid derivatives and α-methylcinnamic acid derivatives with high activities and excellent enantioselectivities (up to 98 % ee). The α-aryloxybutenoic acids can also be hydrogenated by these catalysts to provide the corresponding saturated α-aryloxybutanoic
Enantioselective Hydrogenation of α-Aryloxy α,β-Unsaturated Acids. Asymmetric Synthesis of α-Aryloxycarboxylic Acids
作者:Peter E. Maligres、Shane W. Krska、Guy R. Humphrey
DOI:10.1021/ol0488035
日期:2004.9.1
[reaction: see text] A facile preparation of chiral alpha-aryloxy carboxylic acids via asymmetrichydrogenation of the corresponding unsaturated acids has been discovered. A number of catalysts have been identified that give high product enantioselectivity, and the scope of the reaction has been examined with respect to substitution on the aromatic ring and olefin.