[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.
Catalytic Asymmetric Alkylation Reactions for the Construction of Protected Ethylene-Amino and Propylene-Amino Motifs Attached to Quaternary Stereocentres
作者:Thomas A. Moss、David M. Barber、Andrew F. Kyle、Darren J. Dixon
DOI:10.1002/chem.201203825
日期:2013.2.25
An efficient catalytic and stereoselective method for the direct construction of protected ethylene‐amino and propylene‐amino scaffolds attached to quaternary stereocentres is reported. Preliminary investigations revealed a mild base catalysed nucleophilic ring opening of N‐sulfonyl aziridines using the commercially available phosphazene base 2‐tert‐butylimino‐2‐diethylamino‐1,3‐dimethyl‐perhydro‐1
Enantioselective organocatalytic Michael additions to acrylic acid derivatives: generation of all-carbon quaternary stereocentres
作者:Caroline L. Rigby、Darren J. Dixon
DOI:10.1039/b805233f
日期:——
and N-acryloyl pyrrole have been identified as effective electrophiles in the enantioselectiveMichaeladdition reaction with beta-keto ester pro-nucleophiles catalysed by a cinchona alkaloid derived bifunctional organocatalyst; enantiomeric excesses of up to 98% and yields of up to 96% can be obtained for a range of Michael acceptors and pro-nucleophiles.
An oxidative coupling for the synthesis of arylated quaternary stereocentres and its application in the total synthesis of powelline and buphanidrine
作者:Katherine M. Bogle、David J. Hirst、Darren J. Dixon
DOI:10.1016/j.tet.2010.04.132
日期:2010.8
Catechol derivatives directly bonded to all-carbon quaternary stereocentres are prevalent in nature. An oxidative coupling strategy for the synthesis of this motif is described. Pivoting on the base-catalysed Michael addition of carbon-centred pro-nucleophiles to in situ generated ortho-benzoquinones, the method is broad in scope, high yielding and provides remarkably simple access to this challenging motif. The application of this methodology in the total synthesis of the crinane-type amaryllidaceae alkaloids (+/-)-powelline and (+/-)-buphanidrine is demonstrated and our efforts towards an enantioselective synthesis described. (C) 2010 Elsevier Ltd. All rights reserved.
An Organocatalytic Oxidative Coupling Strategy for the Direct Synthesis of Arylated Quaternary Stereogenic Centers
作者:Katherine M. Bogle、David J. Hirst、Darren J. Dixon
DOI:10.1021/ol702277v
日期:2007.11.1
A broadly applicable oxidative coupling strategy of 3-substituted catechols and carbon-centered pro-nucleophiles for the construction of arylated quaternary stereogenic centers has been developed. Pivoting on a base-catalyzed addition of a carbon-centered acid to an in situ generated o-benzoquinone, the method is general and atom-economical and provides remarkably efficient access to one of the most challenging structural motifs. Furthermore, use of chiral bifunctional organocatalysts allows the process to be rendered asymmetric (up to 81% ee).