Jove
Visualize
お問い合わせ
JoVE
x logofacebook logolinkedin logoyoutube logo
JoVEについて
概要リーダーシップブログJoVEヘルプセンター
著者向け
出版プロセス編集委員会範囲と方針査読よくある質問投稿
図書館員向け
推薦の声購読アクセスリソース図書館諮問委員会よくある質問
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experimentsアーカイブ
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教員リソースセンター教員サイト
利用規約
プライバシーポリシー
ポリシー

関連する概念動画

Reactivity of Enolate Ions01:23

Reactivity of Enolate Ions

Enolate ions are formed by the acid–base reaction of a carbonyl compound with a base. This leads to deprotonation of the α hydrogen atom, leading to a resonance-stabilized enolate ion where one of the contributing structures is an oxyanion, which imparts additional stability. Therefore, the proton on the α carbon is more acidic in nature than that of other sp3-hybridized C–H bonds but less acidic than those in O–H bonds where the negative charge in the conjugate base is localized on the oxygen...
Enolate Mechanism Conventions01:15

Enolate Mechanism Conventions

When a carbonyl compound is treated with a strong base, the α position gets deprotonated to give a resonance-stabilized intermediate called an enolate. Enolates are ambident nucleophiles because they possess two nucleophilic sites that can attack an electrophile owing to the delocalization of the negative charge between the α carbon and oxygen atoms. When the oxygen atom attacks an electrophile, it is called O-attack, whereas electrophilic attack via the α carbon is known as C-attack.
C-attack...
Regioselective Formation of Enolates01:33

Regioselective Formation of Enolates

As depicted in the figure below, the unsymmetrical ketones can form two possible enolates: less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are more stable. But the energy required to form kinetic enolates is less.
Reactivity of Enols01:18

Reactivity of Enols

Enols are a class of compounds where a hydroxyl group is attached to a carbon–carbon double bond, which implies that it is a vinyl alcohol. A carbonyl compound with an α hydrogen undergoes keto–enol tautomerism and remains in equilibrium with its tautomer, the enol form. Usually, the keto tautomer is present in a higher concentration than the enol tautomer due to the higher bond energy of C=O compared to C=C. Moreover, the direction of the keto–enol equilibrium is governed by factors like...
Stereochemical Effects of Enolization01:12

Stereochemical Effects of Enolization

The chiral α-carbon of the carbonyl compound is the stereocenter of the molecule. As shown in the figure below, when such a carbonyl compound undergoes racemization under an acidic or basic condition, an achiral enol is formed.
α-Alkylation of Ketones via Enolate Ions01:10

α-Alkylation of Ketones via Enolate Ions

Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the strong interaction...

こちらも読む

関連記事

共著者、ジャーナル、引用グラフによってこの研究に関連する記事。

並び替え
Same author

[Corrigendum] Adenovirus-mediated overexpression of BMP-9 inhibits human osteosarcoma cell growth and migration through downregulation of the PI3K/AKT pathway.

International journal of oncology·2016
Same author

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability.

Nature communications·2016
Same author

Prednison provokes serum and vasoactive substances in a mice model of immune thrombocytopenia.

Iranian journal of basic medical sciences·2016
Same author

H<sub>2</sub>O<sub>2</sub> and Ca<sup>2+</sup>-based signaling and associated ion accumulation, antioxidant systems and secondary metabolism orchestrate the response to NaCl stress in perennial ryegrass.

Scientific reports·2016
Same author

Advances in the development of aptamer drug conjugates for targeted drug delivery.

Wiley interdisciplinary reviews. Nanomedicine and nanobiotechnology·2016
Same author

Desmoplasia suppression by metformin-mediated AMPK activation inhibits pancreatic cancer progression.

Cancer letters·2016

関連する実験動画

Updated: Jul 3, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
08:12

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

Published on: August 16, 2018

分子間エノラートヘテロカップリング:範囲,メカニズム,応用

Michael P DeMartino1, Ke Chen, Phil S Baran

  • 1Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.

Journal of the American Chemical Society
|August 6, 2008
PubMed
まとめ
この要約は機械生成です。

研究者らは,アミドやケトンなどのカルボニル化合物のスケーラブルな酸化結合方法を開発した. この進歩は,複雑な分子合成における応用によって実証された新しい合成経路を提供します.

さらに関連する動画

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
07:06

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
08:25

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)

Published on: January 17, 2020

関連する実験動画

Last Updated: Jul 3, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
08:12

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

Published on: August 16, 2018

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
07:06

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
08:25

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)

Published on: January 17, 2020

科学分野:

  • 有機化学 オーガニック・ケミストリー
  • 合成方法論 合成方法論
  • カタリシス カタリシス カタリシス

背景:

  • カルボニル化合物の酸化性分子間結合は,有機合成における重要な変換である.
  • 既存の方法は,多様な分子アーキテクチャを作成するための汎用性やスケーラビリティが欠けていることが多い.
  • これらの結合のメカニズム的経路を理解することは,さらなる開発に不可欠です.

研究 の 目的:

  • 様々なカルボニル種の酸化性分子間結合のための信頼性の高いスケーラブルなプロトコルを開発する.
  • 銅 (II) と鉄 (III) を媒介する酸化エノラート結合のメカニズム的な詳細を解明する.
  • 複雑な分子合成における開発された方法論の有用性を実証する.

主な方法:

  • 溶性銅 (II) と鉄 (III) の塩を酸化剤として使用して反応条件の最適化.
  • 単一電子移転と異体化経路に関する研究を含む広範なメカニズム調査.
  • 開発されたプロトコルを,幅広い基板 (40例) とスケールアップ研究に適用する.

主要な成果:

  • アミド,イミド,ケトン,オキシンドールの酸化結合のための効率的でスケーラブルなプロトコルを確立しました.
  • 銅 (II) - (単一電子伝送) と鉄 (III) -媒介 (異体化) プロセスを区別する,深遠な機械的洞察を提供した.
  • この方法を (-) - ブルセヘルニンと医学的に重要なサクシナート誘導体の全合成に成功裏に適用した.

結論:

  • 開発された酸化エノラートヘテロカップリング方法は,堅牢で,スケーラブルで,広く適用可能です.
  • 機械学的研究は,金属媒介の酸化結合反応の批判的理解を提供します.
  • この方法論は,複雑な有機分子を構築するための重要な進歩を表しています.