CeCl3.7H2O: an effective additive in Ru-catalyzed enantioselective hydrogenation of aromatic alpha-ketoesters.
In the presence of catalytic amounts of CeCl 3.7H 2O, [RuCl(benzene)(S)-SunPhos]Cl is a highly effective catalyst for the asymmetric hydrogenation of aromatic alpha-ketoesters. A variety of ethyl alpha-hydroxy-alpha-arylacetates have been prepared in up to 98.3% ee with a TON up to 10,000. Challenging aromatic alpha-ketoesters with ortho substituents are also hydrogenated with high enantioselectivities. The addition of CeCl 3.7H 2O not only improves the enantioselectivity but also enhances the stability of the catalyst. The ratio of CeCl 3.7H 2O to [RuCl(benzene)(S)-SunPhos]Cl plays an important role in the hydrogenation reaction with a large substrate/catalyst ratio.
Meng
Qinghua
Q
School of Chemistry and Chemical Technology, Shanghai Jiaotong University, Shanghai, China.
Sun
Yanhui
Y
Ratovelomanana-Vidal
Virginie
V
Genêt
Jean Pierre
JP
Zhang
Zhaoguo
Z
D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D006865:Hydrogenation; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
D004952:Esters; D007659:Ketones; D009942:Organometallic Compounds; D014867:Water; D002563:Cerium; D012428:Ruthenium; D006859:Hydrogen; C026690:cerous chloride