在室温下用催化β-基托的β-基托的脱化β'-功能化与室温的英多尔
Mikko V Leskinen1, Kai-Tai Yip, Arto Valkonen
1Department of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 JYU, Finland.
Journal of the American Chemical Society
|March 20, 2012
概括
这项研究引入了一种新型的催化反应,用于将β-keto与醇功能化. 该方法在温和条件下实现了高选择性和良好的产量,提供了一个新的合成途径.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- β-基托和英多尔是药品和材料中重要的结构动图.
- 对于合成化学而言,它们直接功能化的高效方法至关重要.
- 现有的方法通常需要恶劣的条件或缺乏区域选择性.
研究的目的:
- 开发一种新型的脱化交叉合反应,用于α-置换β-基托和醇之间.
- 为了实现两个合伙伴的高区域选择性.
- 使用催化剂建立温和的反应条件.
主要方法:
- 帕拉催化脱化合.
- 使用阿尔法替代的β-基托和醇作为基质.
- 在室温温和的温和条件下使用各种氧化剂.
主要成果:
- 实现了高的C3区域选择性,用于醇成分.
- 对于β-基托成分,已证明具有较高的β'-区域选择性.
- 在温和,室温条件下与各种氧化剂获得良好的产品产量.
结论:
- 开发的方法提供了一种高效和选择性的途径,用于合成功能化道和β-基托衍生物.
- 反应在温和的催化下进行,使其对复杂分子合成具有吸引力.
- 提出了两种潜在的反应机制,它们在醇参与的时间上有所不同.
相关概念视频
Aldol Condensation with β-Diesters: Knoevenagel Condensation
The Knoevenagel condensation is an aldol-type reaction involving the condensation of aldehydes or ketones with active methylene compounds such as β-diesters to produce substituted olefins.
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
Baeyer–Villiger oxidation converts aldehydes to carboxylic acids and ketones to esters. The reaction uses peroxy acids or peracids and is often catalyzed by acid. The reaction is named after its pioneers, Adolf von Baeyer and Victor Villiger. The reaction is achieved by a wide range of peracids such as m-chloroperoxybenzoic acid (mCPBA), perbenzoic acid (C6H5COOOH), peracetic acid (CH3COOOH), hydrogen peroxide (H2O2), and tert-butyl hydroperoxide (t-BuOOH).
The carbonyl center is activated by...
The carbonyl center is activated by...
Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization
Dieckmann cyclization is an intramolecular Claisen condensation of diesters. The reaction occurs in the presence of a base and generates a cyclic β-ketoester as the final product. Commonly, 1, 6 and 1, 7-diesters are preferred substrates for the reaction since the generated five, and six-membered cyclic β-keto esters are particularly more stable.
α-Alkylation of Ketones via Enolate Ions
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the strong interaction...
Preparation of Diols and Pinacol Rearrangement
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.


