シリルピリジニウムとキノリニウムカチオンにおけるキラル記憶
Anthony Fernandes1, Claire Laye1, Suman Pramanik1
1Université Bordeaux, CNRS, ISM, UMR 5255 , F-33400 , Talence , France.
Journal of the American Chemical Society
|December 10, 2019
まとめ
研究者はピリジンとキノリンで安定したシリルカチオンを合成し,N-Si相互作用とストレートリングを明らかにした. これらのキラルシリコンの中間物質は 記憶力を発揮し 構成の安定性についての洞察を 提供します
科学分野:
- オルガノシリコン化学
- ヘテロサイクル化学
- 超分子化学
背景:
- シリルカチオンは,シリコン化学において重要な反応性中間物質である.
- シリルカチオンの安定化は,その反応性と性質を理解するための鍵です.
- ヘテロサイクルの化合物は,カチオンの種を安定させるためのユニークな調整の可能性を提供します.
研究 の 目的:
- ピリジンとキノリンで安定したシリルカチオンを合成し,特徴づけること.
- これらの新しいシリルカチオンにおける構造的特徴と結合を明らかにする.
- シリコン・センターの"キラル・メモリー"を 調べるためだ
主な方法:
- 核磁共振 (NMR) スペクトロスコーピ (1H, 13C, 15N, 29Si, 1H DOSY)
- X線 difraktion 試験について
- 密度関数理論 (DFT) の計算
主要な成果:
- ピリジンとキノリンで安定したシリルカチオンが成功しました.
- 構造研究は,N-Si相互作用と四つ組のリングの緊張を明らかにし,シリコンの安定化を確認した.
- チラルの記憶はシリコン原子で観察され,選択性はヘテロサイクルの影響を受けた.
結論:
- N-Si相互作用はシリルカチオンセンターを効果的に安定させる.
- ストレントヘテロサイクリックリングの形成は重要な構造的特徴です.
- シリルカチオンにおけるキラル記憶は示され,構成安定性を理解するための基礎を提供します.
関連する概念動画
Chirality at Nitrogen, Phosphorus, and Sulfur
6.7K
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
6.7K
Prochirality
4.8K
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...
4.8K
Chirality
28.8K
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
28.8K
Stereoisomerism of Cyclic Compounds
10.8K
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,...
10.8K
Molecules with Multiple Chiral Centers
14.7K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
14.7K
Radicals: Electronic Structure and Geometry
4.9K
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
4.9K


