Highly Efficient Ytterbium Triflate Catalyzed Michael Additions of α-Nitroesters in Water
作者:Erik Keller、Ben Feringa
DOI:10.1055/s-1997-5761
日期:1997.7
Michaeladditions of alpha-nitroesters with enones and alpha,beta-unsaturated aldehydes result in quantitative conversions to the corresponding 1,4-adducts by performing the reactions in water in the presence of ytterbiumtriflate as water-tolerant Lewis acid.
A Diastereo- and Enantioselective Synthesis of α-Substituted <i>syn</i>-α,β-Diamino Acids
作者:Anand Singh、Jeffrey N. Johnston
DOI:10.1021/ja8011808
日期:2008.5.1
Highly diastereo- and enantioselective additions of substituted alpha-nitroesters to imines have been developed. High diastereoselection relies on the finding that the combination of chiral proton catalyst 2b and alpha-nitro aryl esters bearing 2,6-disubstitution combine to raise substrate-controlled diastereoselection to >20:1 in favor of the syn diastereomer. Furthermore, the chiral catalyst provides
[EN] ASYMMETRIC MICHAEL AND ALDOL ADDITION USING BIFUNCTIONAL CINCHONA-ALKALOID-BASED CATALYSTS<br/>[FR] ADDITIONS ASYMETRIQUES DE MICHAEL ET D'ALDOL UTILISANT DES CATALYSEURS BIFONCTIONNELS A BASE DE CINCHONINE
申请人:UNIV BRANDEIS
公开号:WO2005121137A1
公开(公告)日:2005-12-22
One aspect of the present invention relates to quinine-based and quinidine-based catalysts. Another aspect of the invention relates to a method of preparing a derivatized quinine-based or quinidine-based catalyst comprising 1) reacting quinine or quinidine with 5 base and a compound that has a suitable leaving group, and 2) converting the ring methoxy group to a hydroxy group. Another aspect of the present invention relates to a method of preparing a chiral, non-racemic compound from a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral ketone, comprising the step of: reacting a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral 10 ketone with a nucleophile in the presence of a catalyst; thereby producing a chiral, non racemic compound; wherein said catalyst is a derivatized quinine or quinidine. Another aspect of the present invention relates to a method of kinetic resolution, comprising the step of reacting racemic chiral alkene with a nucleophile in the presence of a derivatized quinine or quinidine.
METHOD FOR PRODUCING LAMELLARIN AND DERIVATIVE THEREOF
申请人:Tunghai University
公开号:US20180273543A1
公开(公告)日:2018-09-27
The present application discloses a method for producing lamellarin and a derivative thereof, which is able to greatly shorten the synthesis path of the lamellarin and the derivative thereof, and to improve the yield of the lamellarin and the derivative thereof, so as to increase use of the lamellarin or the derivative thereof in pharmaceutical industry.