N-スルフォニルイミンの触媒的非対称酸化は,過酸化水素-トリクロアセトニトリル系を用いて行われます
Daisuke Uraguchi1, Ryosuke Tsutsumi, Takashi Ooi
1Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University , Nagoya 464-8602, Japan.
Journal of the American Chemical Society
|May 18, 2013
まとめ
新しいペイン型酸化は,過酸化水素とトリクロアセトニトリルを使用して,キラルなN-スルフォニルイミンを効率的に生成します. このP-スピロキラル触媒は,広範な応用のための高度なエナチオセレクティブ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
- アシンメトリック・シンセシス
- カタリシス カタリシス カタリシス
背景:
- ペイン型酸化は,有機合成における重要な変換である.
- N-スルフォニルイミンのエナンチオセレクティブ・メソッドの開発は,キラル・ビルディング・ブロックへのアクセスには極めて重要です.
研究 の 目的:
- N-スルフォニルイミンの効率的で高度にエナチオセレクティブなペイン型酸化を開発する.
- 開発されたメソッドの基質一般性および化学選択性を探求する.
主な方法:
- 酸化剤として過酸化水素とトリクロアセトニトリルを使用した.
- P-スピロキラルトライアミノイミノフォスフォランを触媒として使用した.
- 様々なN-スルフォニルイミン基板との反応の範囲を調査した.
主要な成果:
- 効率的で高度にエナチオセレクティブなペイン型酸化が達成された.
- N-スルフォニルイミンの広範な基板一般性を実証した.
- 触媒システムによって誘発されるユニークな化学選択性が観察されました.
結論:
- 開発されたペイン型酸化は,非対称合成のための強力なツールです.
- P-スピロキラル触媒は,エナチオ選択性に対する正確な制御を可能にします.
- この方法は,貴重なキラルN-スルフォニルイミン誘導体へのアクセスを提供します.
関連する概念動画
02:44Oxidation 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.
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...
02:04Oxidation 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.
02:47Alkynes 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.
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.