Enantioselective Hydrogenation of β-Keto Esters using Chiral Diphosphine-Ruthenium Complexes: Optimization for Academic and Industrial Purposes and Synthetic Applications
作者:V. Ratovelomanana-Vidal、C. Girard、R. Touati、J. P. Tranchier、B. Ben Hassine、J. P. Genêt
DOI:10.1002/adsc.200390021
日期:2003.1
Enantioselectivehydrogenationusingchiralcomplexes between atropisomeric diphosphines and ruthenium is a powerful tool for producing chiral compounds. Using a simple and straightforward in situ catalyst preparation, the conditions were optimizedusing molecular hydrogen for both academic and industrialpurposes. This led to the best conditions and the lowest catalytic ratio required for the pressure
Lewis Base Activation of Lewis Acids: Catalytic, Enantioselective Addition of Silyl Ketene Acetals to Aldehydes
作者:Scott E. Denmark、Gregory L. Beutner、Thomas Wynn、Martin D. Eastgate
DOI:10.1021/ja047339w
日期:2005.3.1
The concept of Lewisbase activation of Lewisacids has been reduced to practice for catalysis of the aldolreaction of silyl ketene acetals and silyl dienol ethers with aldehydes. The weakly acidic species, silicon tetrachloride (SiCl4), can be activated by binding of a strongly Lewis basic chiral phosphoramide, leading to in situ formation of a chiral Lewisacid. This species has proven to be a competent
Iridium-catalyzed asymmetric hydrogenation of <font>β</font>-keto esters with f-amphox ligands
作者:Chao Qin、Xiu-Shuai Chen、Chuan-Jin Hou、Hongzhu Liu、Yan-Jun Liu、De-Zhi Huang、Xiang-Ping Hu
DOI:10.1080/00397911.2017.1414267
日期:2018.3.19
ABSTRACT The iridium-catalyzed asymmetric hydrogenation of β-keto esters with chiral tridentate P,N,N-ligands (f-amphox) has been developed. Under the optimized conditions, a wide range of β-keto esters can be hydrogenated smoothly, affording the corresponding β-hydroxy esters in good to excellent enantioselectivities (up to 95% ee). GRAPHICAL ABSTRACT
Chiral Bicyclic NHC/Cu Complexes for Catalytic Asymmetric Borylation of α,β-Unsaturated Esters
作者:Yuya Miwa、Takumi Kamimura、Kiyoaki Sato、Daichi Shishido、Kazuhiro Yoshida
DOI:10.1021/acs.joc.9b02096
日期:2019.11.1
The potential of using chiral bicyclic NHC ligands that exhibit modularity was investigated in the Cu-catalyzed asymmetric borylation reaction of α,β-unsaturatedesters. After screening for ligands and optimization of the reaction conditions, the corresponding products were afforded with good enantioselectivities (up to 85% ee).
Lewis Base Activation of Lewis Acids. Addition of Silyl Ketene Acetals to Aldehydes
作者:Scott E. Denmark、Thomas Wynn、Gregory L. Beutner
DOI:10.1021/ja0282947
日期:2002.11.1
olefinic aldehydes as well as aliphatic aldehydes (albeit more slowly) with excellent enantioselectivity. The homologous tert-butyldimethylsilyl ketene acetal of tert-butyl propanoate adds with nearly exclusive anti diastereoselectivity to a similar range of aldehydes also with excellent enantioselectivity. The origin of the slower reaction rate with aliphatic aldehydes is revealed to be the formation of chlorosilyl