コバルト触媒型アリルC ((sp3) -H 炭酸塩化によるCO2
Kenichi Michigami1, Tsuyoshi Mita1, Yoshihiro Sato1
1Faculty of Pharmaceutical Sciences, Hokkaido University , Sapporo 060-0812, Japan.
Journal of the American Chemical Society
|April 12, 2017
まとめ
新しい触媒方法は,二酸化炭素 (CO2) を使用してアルケンのアルリルC ((sp3) -H結合を効率的にカルボキシル化します. この反応は,価値あるステリル酸誘導体と潜在的に γ-ブチロラクトンへの直接的な経路を提供します.
科学分野:
- 有機化学
- カタリシス
- 持続可能な化学
背景:
- アリルC-H機能化は有機合成における重要な課題である.
- 有機分子に二酸化炭素 (CO2) を効率的に組み込むことは,持続可能な化学にとって極めて重要です.
研究 の 目的:
- 端末アルケンのC ((sp3) -H結合をCO2を用いて直接カルボキシル化するための触媒システムを開発.
- 価値ある炭酸派生物の合成とその後の他の重要な化合物への変換を調査する.
主な方法:
- 触媒としてコバルト (Co) とキサンフォス複合体を利用した.
- 各種アリュアレンと1,4ディエンの反応範囲を調査した.
- 反応条件下で評価された機能群の耐性
主要な成果:
- アリル系C ((sp3) -H結合とCO2の触媒カルボキシル化が達成された.
- 線形ステリル酸とヘキサ-3,5-ディエノ酸を 適度から高度に合成した.
- 他のカルボニル基の存在も含め,優れた地域選択性および顕著な機能群耐性を示した.
結論:
- 単純なアリュアレンからスタイリル酸誘導体を合成するための簡単で選択的な方法を開発した.
- この方法は,後続的な非対称性ダイヒドロキシル化によって γ-ブチロラクトンへの短い合成経路を提供します.
- 触媒のC1構成要素としてCO2の使用の可能性を強調しています.
関連する概念動画
02:50Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
02:10Carbocations
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
01:10Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
01:27Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
01:22Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
01:28Carbon-dioxide Fixation
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...