Herein an efficient Pd-catalyzed asymmetricallylicsubstitution cascade of both (E)- and (Z)-but-2-ene-1,4-diyl dimethyl dicarbonates with α-substituted cyano ketones is described for the preparation of chiral 2,3-dihydrofurans in up to 97% yield with 98% ee. A suggested steric control process has been proposed to illustrate the differences in enantioselectivity between the reactions of (E)- and (Z)-allyl
Process for reducing 3-heteroaryl-3-oxopropionic acid derivatives
申请人:——
公开号:US20030225274A1
公开(公告)日:2003-12-04
The present invention relates to a process for preparing stereoisomerically enriched 3-heteroaryl-3-hydroxycarboxylic esters by reducing 3-heteroaryl-3-oxocarboxylic esters in the presence of ruthenium-containing catalysts.
A Pd-catalyzed asymmetric allylic substitution cascade of allylic meso-dicarbonates with 3-oxo-nitriles has been developed for the synthesis of chiral bicyclic dihydrofurans bearing two vicinal carbon stereocenters. The reaction proceeds via an asymmetric desymmetrization process with the desired products being obtained in high yields and with up to 97% ee. The reaction was performed on a gram-scale
Preparation of N-unsubstituted β-ketoamides by Rhodococcus rhodochrous-catalysed hydration of β-ketonitriles
作者:Vicente Gotor、Ramón Liz、Ana Mª Testera
DOI:10.1016/j.tet.2003.10.096
日期:2004.1
N-unsubstituted β-ketoamides, hardly obtainable or non-accessible by non-enzymatic methods, have been synthesized, with good to excellent yields, by the generally fast hydration of the corresponding β-ketonitriles, catalysed by the bacterium Rhodococcus rhodochrous IFO 15564. This bacterium shows nitrile hydratase and amidase activities, the latter being inhibited during its growth phase with diethyl phosphoramidate
Process for preparing 3-heteroaryl-3-hydroxypropanoic acid derivatives
申请人:——
公开号:US20040181058A1
公开(公告)日:2004-09-16
The invention relates to a process for preparing enantiomer-enriched 3-heteroaryl-3-hydroxypropanoic acid derivatives and 3-heteroaryl-1-aminopropan-3-ols, and to their use.