非対称的に歪んだ,高度にPiベースのポルフィリンモジュールを運ぶサイクルホストを使用して,キラルフルレンC76のワンポットエナンチオセレクティブ抽出
Yoshiaki Shoji1, Kentaro Tashiro, Takuzo Aida
1Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Journal of the American Chemical Society
|April 9, 2010
まとめ
挑戦的なキラルフルレーンC ((76) 解像度は,新しいサイクルホストを使用して達成されます. この宿主体は選択的にC ((76)) のエナティオメールを捕獲し,単一の抽出で有意なエナティオメール過剰を示しています.
科学分野:
- 超分子化学 超分子化学
- ホスト・ゲスト・ケミストリー
- 有機化学 オーガニック・ケミストリー
背景:
- C76) のような非置換キラルフルレンは,光学解像度に対して大きな課題を提示する.
- ホスト・ゲスト化学は,複雑な分子のエナチオマーを分離するための効果的な方法を模索しています.
研究 の 目的:
- キラルフルレンのC ((76) のエナチオセレクティブ解離のための新しいサイクルホストを開発する.
- エナンチオセレクションを担当する宿主の構造的特徴を調査する.
主な方法:
- メソ-ディアリル-ベータ-オクタエチルポルフィリン (P(2H)) とそのキラルなN-2-アセトキシエチル誘導体 (P(N-EtOAc)) を含む新型循環宿主分子の合成 1(2H)).
- 合成された宿主を用いてC ((76)) のエナチオマーを捕まえるエナチオセレクティブ抽出実験.
- 特定の宿主群の貢献度を評価するために,参照宿主群による制御実験を行う.
主要な成果:
- 新型サイクリック宿主1~2Hは,C~76をエナチオセレクティブで成功裏に捕まえた.
- 単一の抽出で,C ((76) の7%のエナティオメア過剰が達成されました.
- 制御実験では,キラルなN置換ポルフィリン単位のpi基本性および非対称的歪みの決定的な役割が強調されました.
結論:
- 設計されたサイクリックホストは,キラルフルレンのC ((76) エナンティオメアを効果的に分解します.
- キラル・ポルフィリン・ユニットの電子的およびステリック的性質は,エナンチオセレクションを達成するための鍵です.
- この研究は,キラルフルレネに挑戦する光学的解像度のための新しい戦略を提供します.
さらに関連する動画
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
関連する概念動画
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
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...