チラルN-ヘテロサイクリックカルベンによって触媒化されたエナチオセレクティブの分子間エナミド-アルデヒドクロスカップリング
Jicheng Wu1, Changgui Zhao1, Jian Wang1
1School of Pharmaceutical Sciences and §School of Medicine, Tsinghua University , Beijing 100084, China.
Journal of the American Chemical Society
|March 30, 2016
まとめ
N-ヘテロサイクリックカルベン (NHC) 触媒は,エナミドとアルデヒド間の新しいクロスカップリング反応を可能にします. この方法は,高収量およびエナチオ選択性で四次炭素中心を持つ有価なキラルアミンを効率的に生成します.
科学分野:
- 有機化学
- カタリシス
- 合成方法論
背景:
- N-ヘテロサイクリックカルベン (NHC) は多用途の有機触媒である.
- 交互結合反応は有機合成において 根本的なものです
- エナミンとアルデヒドは一般的な合成構成要素です.
研究 の 目的:
- 新しいNHC触媒による分子間クロスカップリング反応を 開発する
- 四次炭素中心を持つ,エナティオメリックに濃縮されたN-保護アミンを合成する.
主な方法:
- N-ヘテロサイクリックカルベン (NHC) 触媒を用いた.
- エナミドとアルデヒドの交互結合反応を用いた.
- 収穫量とエナチオ選択性の最適化反応条件
主要な成果:
- エナミドとアルデヒドの 異なった分子間結合が 達成されました
- 高度にエナチオセレクティブなN-保護アミンを提供した.
- 良好な収穫量と高いエナチオ選択性を持つ四次炭素中心を持つ生成製品.
結論:
- 価値あるキラルアミンの 新しく効率的な合成経路を確立しました
- 複雑なC−C結合形成におけるNHC触媒の有用性を実証した.
- 開発された方法は,非対称的な合成のための強力なツールを提供します.
関連する概念動画
Aldehydes and Ketones with Amines: Enamine Formation Mechanism
8.5K
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
8.5K
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
4.3K
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
4.3K
Reactivity of Enols
4.3K
Enols are a class of compounds where a hydroxyl group is attached to a carbon–carbon double bond, which implies that it is a vinyl alcohol. A carbonyl compound with an α hydrogen undergoes keto–enol tautomerism and remains in equilibrium with its tautomer, the enol form. Usually, the keto tautomer is present in a higher concentration than the enol tautomer due to the higher bond energy of C=O compared to C=C. Moreover, the direction of the keto–enol equilibrium is...
4.3K
Stereochemical Effects of Enolization
2.8K
The chiral α-carbon of the carbonyl compound is the stereocenter of the molecule. As shown in the figure below, when such a carbonyl compound undergoes racemization under an acidic or basic condition, an achiral enol is formed.
2.8K
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
10.0K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
10.0K
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
6.5K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
6.5K


