トランジション・メタルフリー γ-C ((sp3) -H メチレン1,2-ジヒドロピリジン合成のためのエナミノンの機能化と溶融三環ピリド[1,2-a]インドール構造における応用
Contact us if these videos are not relevant.
Contact us if these videos are not relevant.
PubMedで要約を見る
まとめ
この要約は機械生成です。研究者は,エナミノンとアルキノンを用いてメチレン機能化された1,2-ジヒドロピリジン (1,2-DHP) の新しい合成を開発した. この効率的な方法は,二重C-H活性化によって複雑なインドル-ピリジン混合構造の作成も可能にします.
科学分野
- 有機化学
- 合成化学
- ヘテロサイクル化学
背景
- エナミノンとアルキノンは有機合成における多用途な構成要素である.
- 機能化されたピリジンへの効率的な合成経路の開発は,重要な関心事である.
- C-H活性化戦略は 分子構造の強力なツールを提供します
研究 の 目的
- メチレン機能化された1,2-ジヒドロピリジン (1,2-DHPs) の合成のための新しい無効反応を開発する.
- エナミノンの新しい γ-C ((sp3) -H 結合変換の有用性を探求する.
- 合成された1,2-DHPを複雑な溶融ヘテロサイクルの構造に適用することを実証する.
主な方法
- β-メチルエナミノンとアルキノンの間の無効反応.
- セシウム炭酸 (Cs2CO3) を用いた触媒
- 二重C-H活性化による1,2-DHP製品の1段階変換
主要な成果
- 幅広い範囲と高効率のメチレン機能化された1,2-ジヒドロピリジン (1,2-DHPs) の合成に成功した.
- エナミノンの γ-C ((sp3) -H 結合の新たな変換が達成された.
- インドル-ピリジンのハイブリッド構造で融合した三環構造の1段階合成が実証された.
結論
- エナミノンとアルキノンから1,2-DHPを合成する新しい効率的な経路が確立されています.
- この方法は,新しい γ-C ((sp3) -H 活性化経路を使用する.
- 合成された1,2-DHPは,二重C-H活性化による複雑な融合ヘテロサイクルの構築のための貴重な中間物質として機能する.
関連する概念動画
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
However, enamines are neutral and less reactive than enolates, which bear a net negative charge. Consequently, enamines are effective Michael donors...
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.
Both imine formation and enamine formation are reversible and...
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...
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
Figure 1.
A primary arylamine attacks the nitrosonium ion to form an...
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.
In the Curtius rearrangement, acyl azides are converted into primary amines under thermal conditions, accompanied by the loss of gaseous N2 and CO2. The loss of nitrogen acts as...