直接接続されたエニネ・ダイノフィルの高度に選択的なディエルス・アルダー反応
Mingji Dai1, David Sarlah, Maolin Yu
1Department of Chemistry, Columbia University, Havemeyer Hall, New York, New York 10027, USA.
Journal of the American Chemical Society
|January 18, 2007
まとめ
リンクされたエニネ・ディエノフィルのダイエルス・アルダー反応は,高い選択性を示しています. オレフィン系部位にある遠隔活性化グループは,地域化学を決定し,天然産物の亜構造物の合成を可能にします.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 合成化学 合成化学とは
背景:
- ダイエルス・アルダー反応は,周期性化合物の形成に不可欠である.
- エニネは,サイクロアディションにおけるユニークな反応性課題を提示します.
研究 の 目的:
- 関連性のあるエニネ・ディエノフィールとのダイエルス・アルダー反応の地域選択性を調査する.
- サイクル添加の結果に対する活性化群の影響を理解する.
主な方法:
- 代用されたエニネ・ダイノフィールによるダイエルス・アルダーサイクル添加反応.
- 観測された反応性と選択性を説明するための計算分析.
主要な成果:
- ディエルス・アルダー反応は,エニネのアセチレン中心部のみで発生した.
- リージオケミストリーは,オレフィン系部位の遠隔活性化群が優勢で,アセチレン系部位の活性化群が優勢であった.
- 計算による研究は,アセチレンサイクル添加と遠隔グループ制御の好みを合理化しました.
結論:
- 結合されたエニネ・ディエノフィルは,ディエルス・アルダー反応において高い選択性を有する.
- リモート・アクティベーション・グループは,地域化学を大幅にコントロールしています.
- これらの発見は,オルセニラートタイプの天然製品への新しい合成経路を開きます.
関連する概念動画
01:24Diels–Alder Reaction: Characteristics of Dienophiles
In a Diels–Alder reaction, the diene is usually an electron-rich system and acts as a nucleophile, whereas the dienophile is electron-deficient and functions as an electrophile. Much like the diene, the nature of the dienophile significantly impacts the outcome of the reaction.
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...
01:29Diels–Alder Reaction: Characteristics of Dienes
The Diels–Alder reaction brings together a diene and a dienophile to form a six-membered ring. Both components have unique characteristics that influence the rate of the reaction.
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
01:31Diels–Alder vs Retro-Diels–Alder Reaction: Thermodynamic Factors
The Diels–Alder reaction is thermally reversible, meaning that the reaction reverts to the starting diene and dienophile under suitable temperatures. The forward reaction gives a cyclohexene derivative and is favored at low to medium temperatures. The reverse process, also called retro-Diels–Alder reaction, is a ring-opening process favored at high temperatures.