アリリミンとダニシェフスキーダイエンの間の効率的で実用的なAg触媒サイクロアディション
Nathan S Josephsohn1, Marc L Snapper, Amir H Hoveyda
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Journal of the American Chemical Society
|April 3, 2003
まとめ
この研究では,Danishefsky dieneとaryl iminesを使用して,効率的な銀触媒化非対称サイクロアディション反応を導入しています. この方法は,容易に準備できるキラルリガンドを使用し,溶媒のないオプションを提供することで,高いエナチオセレクティブ性と収量を達成します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- アシンメトリック・カタリシス
- サイクル添加反応 サイクル添加反応
背景:
- ダニシェフスキーのダイエンは,有機合成における多用途の反応剤である.
- サイクロードダクトの非対称合成は,医薬品開発において極めて重要です.
- エナチオセレクティブなサイクル添加には効率的な触媒方法が必要です.
研究 の 目的:
- アリルイミンにダニシェフスキーのダイネを効率的にアグ触媒で非対称的に加える方法を開発する.
- サイクルロードダクトの形成において,高いエナチオセレクティビティと収量を達成するために.
- 溶媒フリーおよび空気耐性プロトコルを含む,実用的反応条件を探求する.
主な方法:
- 銀 (Ag) 触媒による非対称サイクロアディション反応を用いた.
- Danishefsky dieneと様々なアリルイミンを基底として使用した.
- i-Leu.のような安価な材料から派生した,容易に作製できるキラルリガンドを開発し,使用した.
- 低温 (4°C) で,低触媒負荷 (0.1-1mol %) で研究された反応.
主要な成果:
- サイクルロードダクトでは,≥89%の高エナティオメア過剰 (ee) が達成されました.
- 孤立した高収量≥85%の高収量を得ました.
- 溶媒のない条件下や空気中での成功反応が実証されています.
- リサイクル可能な,第1世代のサポートされたキラル触媒を,5回の成功サイクルで報告しました.
結論:
- 効率的で実用的なAg触媒による非対称サイクロアディション法が確立されています.
- 開発されたキラルリガンドと触媒システムは,貴重なサイクルロードダクトの合成に有効です.
- 再利用可能な触媒と単純化された反応条件の可能性は,この方法の適用性を高めます.
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 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...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
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: 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...


