Tetrazolic Acid Functionalized Dihydroindol: Rational Design of a Highly Selective Cyclopropanation Organocatalyst
摘要:
Herein we wish to report our development of an improved catalyst (S)-(-)-indoline-2-yl-1H-tetrazole (1) for the enantioselective organocatalyzed cyclopropanation of alpha,beta-unsaturated aldehydes with sulfur ylides. The new organocatalyst readily facilitates the enantioselective organocatalytic cyclopropanation, providing cyclized product in excellent diastereoselectivities ranging from 96% to 98% along with enantioselectivities exceeding 99% enantiomeric excess for all reacted alpha,beta-unsaturated aldehydes. The new catalyst provides the best results so far reported for intermolecular enantioselective organocatalyzed cyclopropanation.
Enantioselective Organocatalytic Cyclopropanations. The Identification of a New Class of Iminium Catalyst Based upon Directed Electrostatic Activation
作者:Roxanne K. Kunz、David W. C. MacMillan
DOI:10.1021/ja042774b
日期:2005.3.1
A new method for enantioselectiveorganocatalyticcyclopropanation is described. This study outlines the identification of a new class of iminium catalyst based on the concept of directed electrostatic activation (DEA). This novel organocatalytic mechanism exploits dual activation of ylide and enal substrates through a proposed electrostatic activation and stereodirected protocol. Formation of trisubstituted
描述了一种对映选择性有机催化环丙烷化的新方法。本研究概述了基于定向静电活化 (DEA) 概念的新型亚胺催化剂的鉴定。这种新颖的有机催化机制通过提出的静电激活和立体定向协议利用了叶立德和 enal 底物的双重激活。对多种α、β-不饱和醛和锍叶立德可形成具有高水平对映和非对映诱导的三取代环丙烷。此外,机理研究发现,该环丙烷化反应表现出与提议的 DEA 步骤一致的对映选择性和反应性特征。
Application of novel sulfonamides in enantioselective organocatalyzed cyclopropanation
作者:Antti Hartikka、Adam T. Ślósarczyk、Per I. Arvidsson
DOI:10.1016/j.tetasy.2007.05.030
日期:2007.7
Three novel aryl sulfonamides derived from (2S)-indoline-2-carboxylic acid have been obtained and used as organocatalysts. The catalysts incorporate diverse functionality on the phenyl ring, enabling steric, and electronic fine tuning of the catalysts. The catalysts facilitate the reaction between a range of alpha, beta-unsaturated aldehydes and sulfur ylides, thus providing cyclopropane products in enantiomeric excesses of up to 99%. (c) 2007 Elsevier Ltd. All rights reserved.
N-Heterocyclic Carbene Catalyzed CC Bond Cleavage in Redox Esterifications of Chiral Formylcyclopropanes
作者:Stephanie S. Sohn、Jeffrey W. Bode
DOI:10.1002/anie.200601919
日期:2006.9.11
Organocatalytic asymmetric cyclopropanation of α,β-unsaturated aldehydes with arsonium ylides
作者:Yun-Hui Zhao、Gang Zhao、Wei-Guo Cao
DOI:10.1016/j.tetasy.2007.10.007
日期:2007.10
A novel organocatalytic asymmetric cyclopropanation of alpha,beta-unsaturated aldehydes with arsonium ylides using diphenylprolinol silylether as a catalyst is described. A variety of chiral cyclopropyl aldehydes are obtained in moderate to good yields with up to 99:1 dr (diastereomeric ratio) and 99% ee under simple and mild reaction conditions. (c) 2007 Elsevier Ltd. All rights reserved.
[DE] ORGANISCHE SALZE SOWIE VERFAHREN ZUR HERSTELLUNG VON CHIRALEN ORGANISCHEN VERBINDUNGEN<br/>[EN] ORGANIC SALTS AND METHOD FOR PRODUCING CHIRAL ORGANIC COMPOUNDS<br/>[FR] SELS ORGANIQUES ET PROCÉDÉ DE PRODUCTION DE COMPOSÉS ORGANIQUES CHIRAUX
申请人:STUDIENGESELLSCHAFT KOHLE MBH
公开号:WO2007098741A2
公开(公告)日:2007-09-07
[EN] The invention relates to a method for producing chiral organic compounds by asymmetric catalysis, using ionic catalysts comprising a chiral catalyst anion. The claimed method is suitable for reactions which are carried out over cationic intermediate stages, such as imnium ions or acyl pyridinium ions. The invention enables the production of chiral compounds with high ee values, that until now could only be obtained by means of costly purification methods. [FR] L'invention concerne un procédé de production de composés organiques chiraux par catalyse, procédé selon lequel des catalyseurs ioniques présentant un anion de catalyseur chiral sont utilisés. Ledit procédé convient à la mise en oeuvre de réactions se produisant sur des états intermédiaires cationiques, tels que sur des ions imnium ou sur des ions acylpyridinium. Ce procédé permet de produire des composés chiraux à excès énantiomère élevé qui n'étaient jusqu'à présent obtenus que par des procédés de purification coûteux. [DE] Es wird ein Verfahren zur Herstellung von chiralen organischen Verbindungen durch asymmetrische Katalyse beansprucht, in welchem ionische Katalysatoren eingesetzt werden, die ein chirales Katalysatoranion aufweisen. Das beanspruchte Verfahren ist zur Durchführung von Reaktionen geeignet, die über kationische Zwischenstufen verlaufen, wie über Imniumionen oder über Acylpyridiniumionen. Es können chirale Verbindungen mit hohen ee-Werten hergestellt werden, die bisher nur durch aufwendige Reinigungsverfahren erhalten wurden.