アルケンの鉄触媒カルボニル化-過酸化をアルデヒドおよびヒドロペロキシドで行う
Weiping Liu1, Yuanming Li, Kaisheng Liu
1Department of Chemistry, Renmin University of China, Beijing 100872, China.
Journal of the American Chemical Society
|June 22, 2011
まとめ
新しい3つの成分反応により,アルケーン,アルデヒド,およびヒドロペロキシドからβ-ペロキシケトンを合成します. この方法では,単一ポットまたは段階的なプロセスを通して,α-カルボニルエポキシドを効率的に生成します.
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:
- 複雑な有機分子のための効率的な合成経路の開発は,化学において極めて重要です.
- 鉄触媒は,貴金属触媒の費用対効果が高く,環境に害のない代替手段です.
研究 の 目的:
- β-ペロキシケトンを合成するための新しい3つの成分反応を開発する.
- α-カルボニルエポキシドの合成におけるこの反応の応用を探求する.
主な方法:
- アルケーン,アルデヒド,および水酸化物を含む3つの成分反応で,鉄 (II) クロリド (FeCl2) によって触媒化されます.
- 中間β-ペロキシケトンの段階的または単発塩基誘発エポキシデーション.
主要な成果:
- FeCl2触媒による三成分反応を用いてβ-ペロキシケトンを成功して合成した.
- α-カルボニルエポキシドの合成は,段階的および単一ポットエポキシデーションの両方の方法によって達成されました.
結論:
- 開発された3つの成分反応は,β-ペロキシケトンへの効率的な経路を提供します.
- この方法論は,α-カルボニルエポキシドへの汎用的な経路を提供し,異なる合成戦略に適応できます.
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.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Hydroboration-Oxidation of Alkenes
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
Baeyer–Villiger oxidation converts aldehydes to carboxylic acids and ketones to esters. The reaction uses peroxy acids or peracids and is often catalyzed by acid. The reaction is named after its pioneers, Adolf von Baeyer and Victor Villiger. The reaction is achieved by a wide range of peracids such as m-chloroperoxybenzoic acid (mCPBA), perbenzoic acid (C6H5COOOH), peracetic acid (CH3COOOH), hydrogen peroxide (H2O2), and tert-butyl hydroperoxide (t-BuOOH).
The carbonyl center is activated by...
The carbonyl center is activated by...
Radical Anti-Markovnikov Addition to Alkenes: Mechanism
The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy radical...
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy radical...
Oxidative Cleavage of Alkenes: Ozonolysis
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.


