より高い反応温度で改善された地域選択性を持つアレン環C-C結合にIrの可逆挿入
Martin Jakoobi1, Yancong Tian1, Roman Boulatov1
1Department of Chemistry , University of Liverpool , Crown Street , Liverpool L69 7ZD , United Kingdom.
Journal of the American Chemical Society
|March 19, 2019
まとめ
研究者は,芳香C-C結合に地域選択的なイリジウム挿入を成し遂げ,ダイリジウム金属サイクルを形成した. この突破は,新しいアレン機能化とよりクリーンな化石燃料の変換を可能にし,選択性はステリック要因によって制御されます.
科学分野:
- 有機金属化学
- カタリシス
- 有機合成
背景:
- 芳香C-C結合への地域選択的金属挿入は,アレン機能化とよりクリーンな化石燃料の変換に不可欠です.
- 合成化学において,C−C結合活性化のための効率的な方法の開発は依然として重要な課題である.
研究 の 目的:
- メチルアレンの芳香C-C結合にイリジウムの可逆挿入を報告する.
- ディアリジウム金属サイクルの形成を調査し,その同位体選択性を制御する.
主な方法:
- イリジウム複合体を用い,メタルを η4結合メチルアレンに挿入する.
- 変数温度 (50~150°C) を用いて反応結果を分析する.
- 反応メカニズムを解明するために,運動理論と密度関数理論 (DFT) を実施する.
主要な成果:
- リバーシブルなイリジウム挿入により,最大99%の8つ組のダイリジウムメタラサイクルが得られる.
- 温度に依存する選択性が実証され,1つの同位体が150°Cで優勢である.
- メチル群とCp*リガンドの間のステリック排斥が,地域選択性を支配する重要な要因として特定された.
結論:
- 芳香C−C結合に地域選択的にイリジウムを挿入する方法を確立した.
- より高い温度でのイリジウムの挿入の可逆性は,均衡と選択的な製品形成を可能にします.
- この研究は,新しいアレン機能化戦略とよりクリーンな化学変換の基盤を提供します.
関連する概念動画
02:55Temperature Dependence on Reaction Rate
88.9K
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
88.9K
02:49Bond Energies and Bond Lengths
31.4K
Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, that is, the energy necessary to separate the bonded atoms. Separating any pair of bonded atoms requires energy — the stronger a bond, the greater the energy required to break it.
31.4K
02:28Effect of Temperature Change on Reaction Rate
5.1K
The Arrhenius equation,
5.1K
02:43Peptide Bonds
82.7K
A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid's carboxyl group and another amino acid's amino group combine, releasing a water molecule. The resulting bond is the peptide bond. The products that such linkages form are peptides. As more amino acids join this growing chain, the resulting chain is a polypeptide. Each polypeptide has a free amino group at one end. This end has the N-terminal, or the amino-terminal, and the other end has a free...
82.7K
00:57C–C Bond Cleavage: Retro-Aldol Reaction
7.6K
The reverse of the aldol addition reaction is called the retro-aldol reaction. Here, the carbon–carbon bond in the aldol product is cleaved under acidic or basic conditions to form two molecules of carbonyl compounds. The mechanism of the reaction consists of three steps.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
7.6K
01:08Types of Chemical Reactions: Exchange and Reversible
10.6K
An exchange reaction is a chemical reaction in which both synthesis and decomposition occur, chemical bonds are both formed and broken, and chemical energy is absorbed, stored, and released.
A special kind of exchange reaction is the oxidation-reduction reaction, or the redox reaction. These reactions involve the transfer of electrons from one compound to another. The electrons in these reactions commonly come from hydrogen atoms, which consist of an electron and a proton. A molecule gives up a...
A special kind of exchange reaction is the oxidation-reduction reaction, or the redox reaction. These reactions involve the transfer of electrons from one compound to another. The electrons in these reactions commonly come from hydrogen atoms, which consist of an electron and a proton. A molecule gives up a...
10.6K