碳酸的有机催化功能化:异尿催化不对称的分子内和分子间迈克尔添加 - - 乳酸化
Dorine Belmessieri1, Louis C Morrill, Carmen Simal
1EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, UK.
Journal of the American Chemical Society
|February 10, 2011
概括
特拉米索尔和性异尿素催化不对称的迈克尔添加. 这些反应产生高度立体控制的碳和异环产物,包括功能化的印和二二硫碳酸盐.
科学领域:
- 有机化学 有机化学
- 不对称的催化剂.
背景情况:
- 在合成化学中,开发有效的催化方法来制造复杂的性分子至关重要.
- 迈克尔加法反应是基本的碳-碳键形成过程,它们的不对称变体非常受欢迎.
研究的目的:
- 探索特拉米索尔和奇拉性异尿素作为非对称迈克尔添加-乳酸化反应的有机催化剂的实用性.
- 在合成有价值的异环化合物中实现高水平的二选择性和反选择性.
主要方法:
- 催化不对称的分子内迈克尔添加-乳酸化使用Tetramisole与enone酸.
- 催化不对称的分子间迈克尔添加-乳酸化,使用带有酸和α-keto-β,γ-不和 Ester 的奇拉性异尿素.
主要成果:
- 特拉米索尔调解了分子内反应,产生了具有出色的二极管控制 (高达99:1 dr) 和二极管控制 (高达99% ee) 的碳化合物和异环产物.
- 基拉尔异尿素促进了分子间反应,产生具有高二选择性 (高达98:2dr) 和反选择性 (高达99%ee) 的抗二胺.
- 合成的产品很容易被衍生成功能化的印和二二二氧化碳酸盐.
结论:
- 特拉米索尔和性异尿素是不对称的迈克尔添加-乳酸化反应的有效器官催化剂.
- 这些催化系统提供了一条强大的通路,以致于密集的功能化性内,二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二二
相关概念视频
01:08Conjugate Addition of Enolates: Michael Addition
The attack of a nucleophile at the β carbon of an α,β-unsaturated carbonyl compound is called conjugate addition. Conjugate addition reactions of active methylene compounds, such as β-diketones, β-keto esters, β-keto nitriles, and α-nitro ketones, are called Michael addition reactions.
01:09Conjugate Addition to α,β-Unsaturated Carbonyl Compounds
α,β-Unsaturated carbonyl compounds are molecules bearing a carbonyl and alkene functionality in conjugation with each other. The conjugation in the molecule leads to three resonance structures. The hybrid form exhibits two probable electrophilic sites: the carbonyl carbon and the β carbon.
01:07Preparation of Acid Anhydrides
One of the methods for preparing symmetrical or unsymmetrical acid anhydrides involves the treatment of acid chlorides with the sodium salt of carboxylic acids. The reaction proceeds via a nucleophilic acyl substitution.
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
01:08Nitriles to Carboxylic Acids: Hydrolysis
Nitriles undergo acid-catalyzed hydrolysis or base-catalyzed hydrolysis to form a carboxylic acid. These reactions proceed via an amide intermediate.
01:41Reactions of Carboxylic Acids: Introduction
Carboxylic acids possess an acidic –COOH functional group. The acidity can be attributed to the resonance stabilization of their conjugate base, wherein the negative charge is delocalized over both oxygen atoms.
01:27Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).