ロタキサンと金属イオン交換可能な分子シャトルのダイエルス・アルダー活性テンプレート合成
James D Crowley1, Kevin D Hänni, David A Leigh
1School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, United Kingdom.
Journal of the American Chemical Society
|March 26, 2010
まとめ
この研究では,金属のルイス酸を用いて[2]ロタキサンを合成し,ダイエルス・アルダー反応とテンプレート分子組立を触媒化する. 金属触媒は最終的なロタキサンに留まり,さらなる分子操作を可能にします.
科学分野:
- 超分子化学 超分子化学
- オーガニック・シンセシス オーガニック・シンセシス
- 協調化化学について
背景:
- テンプレート誘導合成は,複雑な分子構造に不可欠である.
- 金属イオンは,有機反応のテンプレートや触媒として作用する.
- ロタキサンは,ユニークな性質を持つ機械的に相互に絡み合っている分子です.
研究 の 目的:
- 金属のルイス酸を用いた[2]ロタキサンの新種の合成を開発する.
- ルイス酸をダイエルス・アルダー反応の触媒とテンプレートとして利用する.
- 最終的なロタキサン構造における金属結合部位の保持を調査する.
主な方法:
- Zn ((II) または Cu ((II) のルイス酸を用いて,ダイエルス-アルダーサイクル添加を触媒化する.
- 多歯ピリジルまたはビピリジンのマクロサイクルを使用して,デオノフィルの方向性をテンプレートします.
- ケラートされたディエノフィルと"止まった"ディエンを反応させる.
主要な成果:
- [2]ロタキサンの合成が成功し,産量は最大91%に達した.
- 金属結合部位がロタキサン構造の中で無傷のままであることの実証.
- 留まった金属の場所を利用して,切り替え可能なマクロサイクルの位置を持つ分子シャトルを作成します.
結論:
- 金属のルイス酸は効率的に触媒とテンプレート [2]rotaxane合成することができます.
- アクティブテンプレートアプローチでは,金属の調整部位を保持した機能的なロタキサンを作成できます.
- これらのロタキサンは,高度な分子機械とスイッチを開発するためのプラットフォームとして機能します.
関連する概念動画
[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.
Diels–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.
Diels–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.
Diels–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...
Diels–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...
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.


