環横ダイエルス・アルダー反応の非対称な触媒
Emily P Balskus1, Eric N Jacobsen
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
Science (New York, N.Y.)
|September 22, 2007
まとめ
この研究は,複雑な分子合成のための触媒的非対称的トランスアヌラーディエルス・アルダー反応を導入します. この方法は,高いステレオ化学的制御を持つポリサイクル化合物を生成し,新しい合成戦略を提供します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- 合成化学 合成化学とは
背景:
- トランスアヌーラ反応は複雑な分子構造を提供する.
- これらの反応におけるステレオ化学的結果の制御は難しい.
- チラルの触媒は,トランスアヌル反応には適用されていない.
研究 の 目的:
- 触媒的非対称トランスアヌーラール・ディエルス・アルダー反応を開発する.
- ポリサイクリック製品合成において高いエナティオメリック過剰を達成するために.
- 自然製品の総合合成における有用性を実証する.
主な方法:
- 新規のキラル触媒システムの開発.
- 触媒系を環横ダイエルス・アルダー反応に適用する.
- 11,12-diacetoxydrimaneの総合成における反応を利用する.
主要な成果:
- 触媒的非対称トランスアヌーラール・ディエルス・アルダー反応は,高エナティオメール過量を持つポリサイクル製品を生成する.
- 触媒は,既存のキラルセンターを有する基板におけるダイアステレオ選択性に影響を与える.
- セスクイテルペンの天然製品の完全な合成が成功しました.
結論:
- 触媒的非対称なトランスアニュラルのダイエルス・アルダー反応は実現可能で効果的です.
- このアプローチは,複雑なポリサイクルのステレオ制御合成のための強力なツールを提供します.
- この方法論は,テルペンの天然製品フレームワークへの一般的な経路を提供します.
関連する概念動画
![[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: 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...
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.
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
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...