イソシアニドの触媒変換におけるルテニウムとシリコンの重要な協力性
Mark C Lipke1, Allegra L Liberman-Martin1, T Don Tilley1
1Department of Chemistry, University of California , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|July 8, 2016
まとめ
複数の金属-水素-シリコン結合を持つルテニウム複合体はイソシアン化物の変換を媒介する. これらの反応はシリコンを
科学分野:
- 有機金属化学
- カタリシス
- シリコン化学
背景:
- M-H-Si結合を持つルテニウム複合体は,知られている触媒である.
- イソシアニドは有機合成における多用途の不飽和基質である.
研究 の 目的:
- イソシアン化物に対する複数のM-H-Si結合を持つルテニウム複合体の反応性を調査する.
- これらの複合体によって媒介されるアイソシアン化変異のメカニズムを解明する.
- 移行金属触媒反応におけるシリコンの役割を調査する.
主な方法:
- ルテニウム-シラン複合体の合成と特徴付け.
- 制御された条件下でイソシアン化物との反応
- デュテリウムラベル付け,運動同位体効果 (KIE) 研究,NMRスペクトル検査
主要な成果:
- ルテニウム複合体とイソシアン化物からカルベン複合体の形成.
- 複合体2aは,水塩化,水素化,C-H活性化によりシラサイクロインドリン産物を生成した.
- コンプレックス1cはイソシアン化還元結合を催化してアルケンを形成する.
- メカニズムの研究により,様々なシリコン調整種が関与していることが明らかになった.
結論:
- ルテニウム-シラン複合体は,偽触媒および触媒反応を含む複雑なアイソシアン化変異を媒介することができる.
- シリコンは複雑な役割を果たし,複数の調整モードとM-H-Si結合を通して参加します.
- これらの発見は,移行金属触媒におけるシリコンの有用性の理解を広げています.
関連する概念動画
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
4.0K
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...
4.0K
01:22Heterogeneous Catalysis
75
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...
75
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.3K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
9.3K
01:20Radical Reactivity: Concentration Effects
1.9K
In a radical reaction, the concentration of starting materials governs the selectivity of a radical. For example, the reaction between an alkyl halide and an alkene, in the presence of tin hydride and AIBN, begins with the generation of a tin radical. The generated radical then abstracts halogen from the alkyl halide, producing an alkyl radical. This alkyl radical can either react with tin hydride, yielding an alkane, or add to an alkene, generating a nitrile-stabilized radical, eventually...
1.9K
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
7.9K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
7.9K
02:50Catalysis
31.8K
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.
31.8K