複合ダイエンとポリエネの合成のための酸化ヘックビニレーション
Jared H Delcamp1, Paul E Gormisky, M Christina White
1University of Mississippi, University, Mississippi 38677, USA.
Journal of the American Chemical Society
|May 25, 2013
まとめ
この研究は,複雑なダイエンとポリエネを生成するための新しい酸化ヘック反応を提示しています. この方法は,単一の結合パートナーのみを活性化することで効率を向上させ,ステレオ定義結合ダイエンの選択的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
- カタリシス カタリシス カタリシス
- 合成方法論 合成方法論
背景:
- ヘック反応は,炭素-炭素結合形成のための強力なツールです.
- ヘック反応の以前の制限には,パラジウム-水素同体化によるステレオ定義結合ダイエンの形成における困難が含まれていた.
- 複雑なダイエンとポリエンの合成のための選択的方法の開発は,依然として重要な課題です.
研究 の 目的:
- 複雑なダイエンとポリエネの選択合成のための新しい酸化ヘック反応を導入する.
- 伝統的なヘック反応におけるパラジウム水化物のイソメリゼーションに関連した制限を克服するために.
- 結合ダイエネとポリエネのより効率的な合成戦略を開発する.
主な方法:
- 酸化性Pd (II) /硫黄酸化物触媒システムを使用しました.
- 使用されている非活性化末端オレフィン (1等価) とビニルボロンエステル (1.5等価).
- ステレオ定義の結合ダイエネとポリエネを生成する反応の能力を調査した.
主要な成果:
- 複雑なダイーンとポリエンの選択的形成を良好な収穫量で達成した.
- 優れたステレオ選択性を示した (E:Z = >20:1; internal:terminal = >20:1).
- 単一のビニル炭素のみの活性化を必要とし,合成効率の向上を示した.
結論:
- 小説の酸化ヘック反応は,ステレオ定義結合ダイエンとポリエネを合成するための堅固な方法を提供します.
- このアプローチは,以前の制限を回避し,効率と選択性を高めます.
- この方法論は,多様な機能に適用可能であり,合成有機化学における重要な進歩を表しています.
関連する概念動画
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
Preparation of Epoxides
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
[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...

