イミネとアミノアルカンの誘導体の触媒的な炭素-炭素結合形成反応
Yi-Jing Chen1, Kazutaka Seki, Yasuhiro Yamashita
1Department of Chemistry, School of Science, The University of Tokyo, and the HFRE Division, ERATO, Japan Science Technology Agency, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|February 20, 2010
まとめ
この研究は,9-フッ素ニリデンの保護を利用して,アミノアルカンとイミンの間の炭素-炭素結合を形成するための新しい触媒方法を導入しています. この反応により,高収量とダイアステレオ選択性が得られ,非対称合成の可能性が生まれます.
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:
- アミノアルカンとイミンは,有機合成における重要な構成要素である.
- C-C結合形成のための効率的な触媒方法は非常に求められています.
- グループを保護することは,反応性と選択性を制御する上で重要な役割を果たします.
研究 の 目的:
- アミノアルカンとイミンの間の新しい触媒C-C結合形成反応を開発する.
- 9-フッ素エニリデンを窒素原子の保護および活性化グループとして利用する.
- 高い収穫量,ダイアステレオ選択性,および非対称な変種を探求するために.
主な方法:
- 9-フッ素ニリデンの保護を使用したイミンとアミノアルカンの触媒結合.
- KO(t) Bu/18-crown-6またはカリウム2,6-ジメチルフェノキシドを触媒として使用しています.
- 酸性デプロテクションにより,最終的なアミン製品が得られ,9-フッ素ロレノンが回収されます.
主要な成果:
- 高い収量とダイアステロ選択性を持つ成功した触媒C-C結合形成.
- 様々なアミノアルカンとイミンのための広範な基板範囲が実証されています.
- モノアミンおよびダイアミン誘導体を生成する選択的脱保護を達成し,定量的な9-フッ素ロレノンの回収を行います.
- 予備的な非対称的な変種は,有望なエナチオセレクティブ性を示した.
結論:
- 開発された方法は,アミノアルカンとイミンを含むC-C結合形成の効率的な経路を提供します.
- 9-フッ素エニリデンのグループは,効果的な保護および活性化剤として機能します.
- この方法論は汎用性があり,非対称合成にも対応し,キラルアミンの生産に新たな道を開く.
関連する概念動画
01:16Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview
Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.
01:23Aldehydes and Ketones with Amines: Imine Formation Mechanism
Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
01:14Aldehydes and Ketones with Amines: Enamine Formation Mechanism
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
01:38Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Carbonyl compounds and primary amines undergo reductive amination first to produce imines, followed by secondary amines in the same reaction mixture, using selective reducing agents like sodium cyanoborohydride or sodium triacetoxyborohydride. Reductive amination produces different degrees of substitution of amines depending on the starting amine substrate.
01:19Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
01:29Preparation of Amides
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...