関連する実験動画
Updated: Aug 8, 2025
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
05:15
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
6.9K
自己組み立てカプセルにおけるオキシメスの選択的結合と同体化
Kuppusamy Kanagaraj1, Rui Wang1, Ming-Kai Zhao1
1Center for Supramolecular Chemistry & Catalysis and Department of Chemistry, College of Science, Shanghai University, Shanghai 200444, China.
Journal of the American Chemical Society
|March 1, 2023
まとめ
研究者らは,アルドキシムのZ同位体を選択的に結合して分離する新しいカプセルを開発しました. この超分子システムは,カプセル内のE-Zイソメリゼーションを容易にし,新しい分離とイソメリゼーション戦略を提供します.
科学分野:
- 超分子化学
- 有機合成
- 材料科学
背景:
- アルドキシムはE/Z同位体として存在し,しばしば分離を困難にする類似の性質を有する.
- カルコゲン結合は,分子認識のためのユニークな非共性相互作用を提供します.
- 超分子カプセルは 化学プロセスのための制御された環境を提供する.
研究 の 目的:
- 機能化されたアルキルOメチルアルドキシームを合成する.
- 超分子カプセル内のアルドキシムイソメアの選択的結合とイソメリゼーションを調査する.
- ゲスト構造とカプセル環境がE-Zイソメリゼーションに与える影響を調べる.
主な方法:
- 様々な機能群を持つC7-C13アルキル-O-メチルアルドキシムの合成
- 水溶性ベンゾセレノジアゾールカプセルを用いたカプセル化試験
- NMRスペクトロスコーピーと拡散オーダースペクトロスコーピー (DOSY) を用いた特徴付け.
- 結合親和性と異体化メカニズムを理解するための計算モデリング.
主要な成果:
- 合成されたアルドキシムは,溶液で約60:40のE/Z同位体比を示した.
- ベンゾセレノディアゾールカプセルは,Z同位体に対して高い選択性を示した.
- 最適なゲストチェーン長 (14重原子) は,分離のための99%以上のE-からZ-同位体選択性を達成した.
- カプセル内で発生したE- Zイソメリゼーションは,超音波で加速された.
結論:
- 超分子封じ込めにより,アルドキシム同位体の選択的結合と分離が可能である.
- カプセル環境は,E-Zイソメリゼーションを促進し,制御する.
- このシステムは,同位体分離とダイナミックな分子プロセスのための有望なプラットフォームを提供します.
関連する概念動画
Preparation of Epoxides
7.9K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
7.9K
Acid-Catalyzed Ring-Opening of Epoxides
7.5K
Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
7.5K
Base-Catalyzed Ring-Opening of Epoxides
8.7K
Due to their highly strained structures, epoxides can readily undergo ring-opening reactions through nucleophilic substitution, either in the presence of an acid or a base. The nucleophilic substitution reactions in the presence of acid are called acid-catalyzed ring-opening reactions, and nucleophilic substitution reactions in the presence of a base are called base-catalyzed ring-opening reactions. Epoxides undergo base-catalyzed ring-opening reactions in the presence of a strong nucleophile...
8.7K
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.5K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
14.5K
Regioselectivity of Electrophilic Additions-Peroxide Effect
8.8K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
8.8K
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.6K
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.
10.6K

