ベンゾシラシクロブテンとアルキンのリガンド制御のRegiodivergentリング拡張 軸性シラシクロヘクセニルアレンへの経路
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PubMedで要約を見る
まとめ
この要約は機械生成です。リンガンド腔の大きさは,ベンゾシラサイクロブテン環の拡大における地域選択性を制御する. 小型リガンドはSi-Csp3製品を産生し,大型のリガンドはSi-Csp2製品を産生し,キラルシラサイクロヘクセニルアレンのエナチオセレクティブ合成を可能にします.
科学分野
- 有機金属化学
- 非対称な触媒
- 合成有機化学
背景
- ベンゾサイクロブテンは,シリコン化学における多用途な構成要素である.
- 環膨張反応における地域選択性およびエナチオ選択性の制御は,依然として課題である.
研究 の 目的
- ベンゾシラサイクロブテンのリガンド制御された地域分岐性およびエナチオセレクティブリング拡張を達成する.
- リガンド腔の大きさによる反応結果の影響を調べる.
主な方法
- 内部のナフチルアルキンを反応パートナーとして利用した.
- (S) - 8H-ビナフチルフォスフォラミド酸と (R) - スピロフォスフォラミド酸の2つの異なるリガンドを使用した.
- 反応メカニズムを解明するために,密度関数理論 (DFT) の計算を行った.
主要な成果
- リガンドの穴の大きさを調整することで,リングの拡大の地域選択性が決定された.
- 広大なリガンド腔はSi-Csp3環の膨張を好み, (S) -1-シラサイクロヘクセニルアレンを生成した.
- コンパクトなリガンド腔はSi-Csp2環の膨張を好み, (S) - 2 - シラサイクロヘクセニルアレンを生成した.
- 2つの経路で高いエナチオ選択性が得られた.
結論
- リンガンドの設計は,ベンゾシラサイクロブテン環の膨張のステレオ化学的結果を制御するために不可欠です.
- この研究は,価値ある軸性キラルオルガノシリコン化合物を合成するための新しい方法を提供します.
- DFT計算は,観測された地域およびエナチオ選択性に関するメカニズム的洞察を提供します.
関連する概念動画
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
Dienophiles with one or more electron-withdrawing substituents form stereochemically different products in which the substituents are oriented in an endo (towards) or exo (away) configuration relative to the double bond.
The endo isomer is formed faster and is the kinetic product. The exo isomer is more stable and is the thermodynamic...
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
For the electrons to flow seamlessly between the two π systems, specific stereochemical and conformational requirements must be met.
Stereochemical Orbital Symmetry
The frontier molecular orbitals that satisfy the symmetry...
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The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
From a molecular orbital perspective, the interacting lobes of the two π systems must be in phase...
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Reaction Mechanism
In the first step, a π...
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
The feasibility of cycloaddition reactions under thermal and photochemical conditions can be...
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
A...