1196988-56-3Relevant academic research and scientific papers
A new class of tunable dendritic diphosphine ligands: Synthesis and applications in the Ru-catalyzed asymmetric hydrogenation of functionalized ketones
Ma, Baode,Miao, Tingting,Sun, Yihua,He, Yanmei,Liu, Ji,Feng, Yu,Chen, Hui,Fan, Qing-Hua
supporting information, p. 9969 - 9978 (2014/08/18)
A series of tunable G0-G3 dendritic 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) ligands was prepared by attaching polyaryl ether dendrons onto the four phenyl rings on the P atoms. Their ruthenium complexes were employed in the asymmetric hydrogenation of β-ketoesters, α-ketoesters, and α-ketoamides to reveal the effects of dendron size on the catalytic properties. The second- and third-generation catalysts exhibited excellent enantioselectivities, which are remarkably higher than those obtained from the small molecular catalysts and the first-generation catalyst. Molecular modeling indicates that the incorporation of bulky dendritic wedges can influence the steric environments around the metal center. In addition, the ruthenium catalyst bearing a second-generation dendritic ligand could be recycled and reused seven times without any obvious decrease in enantioselectivity.
Catalytic enantioselective arylation of glyoxylate with arylsilanes: Practical synthesis of optically active mandelic acid derivatives
Aikawa, Kohsuke,Hioki, Yueta,Mikami, Koichi
supporting information; experimental part, p. 2346 - 2350 (2011/06/26)
Just a little does the trick! The catalytic enantioselective arylation using chiral dicationic palladium complexes provides a reliable and useful access to enantiomerically enriched mandelic-acid derivatives. Significantly low catalyst loading (down to 0.002 mol%) as well as easy catalyst handling are the advantage of this practical method.
A rapid and green approach to chiral α-hydroxy esters: asymmetric transfer hydrogenation (ATH) of α-keto esters in water by use of surfactants
Yin, Lu,Jia, Xian,Li, Xingshu,Chan, Albert S.C.
experimental part, p. 2033 - 2037 (2010/01/16)
A series of α-hydroxy esters were rapidly prepared (1.5 h) from α-keto esters via asymmetric transfer hydrogenation (ATH) in water by the use of surfactants for the first time. This green method, catalyzed by a water-soluble and recyclable Ru(II) complex, gave moderate to high enantioselectivities (up to 99.7% ee) with DTAB as an additive and HCOONa as the hydrogen source.
CeCl3·7H2O: An effective additive in ru-catalyzed enantioselective hydrogenation of aromatic α-ketoesters
Meng, Qinghua,Sun, Yanhui,Ratovelomanana-Vidal, Virginie,Genet, Jean Pierre,Zhang, Zhaoguo
, p. 3842 - 3847 (2008/09/21)
(Chemical Equation Presented) In the presence of catalytic amounts of CeCl3·7H2O, [RuCl(benzene)(S)-SunPhos]Cl is a highly effective catalyst for the asymmetric hydrogenation of aromatic α-ketoesters. A variety of ethyl α-hydroxy-α-arylacetates have been prepared in up to 98.3% ee with a TON up to 10 000. Challenging aromatic α-ketoesters with ortho substituents are also hydrogenated with high enantioselectivities. The addition of CeCl3·7H2O not only improves the enantioselectivity but also enhances the stability of the catalyst. The ratio of CeCl3·7H2O to [RuCl(benzene)(S)-SunPhos]Cl plays an important role in the hydrogenation reaction with a large substrate/catalyst ratio.
