Fréchet-type core-functionalized chiral diamine-based dendritic ligands and hybrid dendritic ligands condensed from polyether wedge and Newkome-type poly(ether-amide) supported multiple ligands were designed and synthesized. The solubility of hybrid dendrimers was found to be finely controlled by the polyether dendron. The catalytic efficiency and recovery use of dendritic ruthenium complexes were compared
Cobalt‐Catalyzed Transfer Hydrogenation of α‐Ketoesters and
<i>N</i>
‐Cyclicsulfonylimides Using H
<sub>2</sub>
O as Hydrogen Source
作者:Yang Gao、Xuexin Zhang、Ronibala Devi Laishram、Jingchao Chen、Kangkui Li、Keyang Zhang、Guangzhi Zeng、Baomin Fan
DOI:10.1002/adsc.201900636
日期:2019.9.3
A Co‐catalyzed effective transferhydrogenation of various α‐ketoesters and N‐cyclicsulfonylimides by safe and environmentally benign H2O as hydrogensource is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N‐cyclicsulfonylimides.
Multiple Dendritic Catalysts for Asymmetric Transfer Hydrogenation
作者:Ying-Chun Chen、Tong-Fei Wu、Jin-Gen Deng、Hui Liu、Xin Cui、Jin Zhu、Yao-Zhong Jiang、Michael C. K. Choi、Albert S. C. Chan
DOI:10.1021/jo0257795
日期:2002.7.1
and were well-characterized by NMR and MS techniques. Their ruthenium complexes prepared in situ had good solubility in the reaction medium (azeotrope of formic acid and triethylamine) and demonstrated high catalytic activity and enantioselectivity comparable to monomeric catalysts in the asymmetric transfer hydrogenation of ketones and imines. Quantitative yields and for some cases a slightly higher
This invention relates to peptidyl compounds of the formulas (I) and (II) active as cathepsin S, a cysteine protease, inhibitors. The compounds are selective, reversible inhibitors of the cathepsin S are therefore useful in the treatment of autoimmune and other diseases. The invention also relates to processes for preparing such compounds and pharmaceutical compositions comprising them.
1
Enantiomerically pure isoxazolines via addition of nitrile oxides to chiral N-acryloyl toluene-2,α-sultams
作者:Wolfgang Oppolzer、Arend J. Kingma、Sasi K. Pillai
DOI:10.1016/s0040-4039(00)93489-0
日期:1991.9
New saccharine-derived, crystalline acryloylsultams undergo efficient 1,3-dipolar cycloadditions of nitrileoxides with ≥95:5 stereoface discrimination. Products or are purified by simple crystallization and cleaved with recovery of the chirophore to provide optically pure Δ2-isoxazolines .