エタ3-シラプロパルギル/アルキニルシリルモリブデン複合体:合成,構造,メタノールに対する反応性
Mako Yabe-Yoshida1, Chizuko Kabuto, Kuninobu Kabuto
1Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Journal of the American Chemical Society
|June 13, 2009
まとめ
エタ(3) -シラプロパルギルリガンドを含む新種の有機金属複合体が合成されました. これらの複合体はメタノールと反応し,メタラサイクルとアリル複合体を形成し,有機シリコン化学を拡張します.
科学分野:
- 有機金属化学 有機金属化学
- シリコン化学 シリコン化学
- 協調化化学について
背景:
- 新種の有機金属化合物の合成は,新しい触媒および材料アプリケーションの開発に不可欠です.
- オーガノシリコン化合物は,シリコン原子の特性によりユニークな性質を提供します.
研究 の 目的:
- モリブデンの新型エタ (((3) -シラプロパルギルおよびアルキニルシリル複合体を合成し,特徴づけること.
- これらの新しい複合体のメタノールとの反応性を調査する.
主な方法:
- アルキニルシラネとCp*(CO) (((2) ((MeCN) MoMeの反応により,エタ(3) -シラプロパルギル/アルキニルシリル複合体の合成.
- NMRスペクトロスコピーとX線結晶学を用いた構造的特徴化.
- メタノールとの反応を含む反応性研究.
主要な成果:
- 新種のエタ (3) -シラプロパルギル/アルキニルシリル複合体 (Cp * CO) 2 Mo 3 -エタ 3 -Ph 2 SiCCR) が成功して合成されました (3a, R = (t) Bu; 3b, R = (i) Pr).
- 複合体3aはメタノールと反応して,安定した4つ構成の金属サイクルCp*(CO)(2) MoC(=CH(t) Bu) SiPh(2) OMe (5a) を生成した.
- 複合体3bはメタノールと反応して,中間金属サイクル (5b) を通して,エタ{3) -アリル複合体Cp*(CO)(2) Mo{eta(3) -MeOPh(2) Si) HCCHCMe(2) } (7) を形成する.
結論:
- この研究は,新しいオルガノシリコン-モリブデン複合体の合成と特徴付けの成功を示しています.
- 反応性研究により,メタノールと反応した際にメタラサイクルとエタ ((3) -アリル複合体の形成の明確な経路が明らかになりました.
- これらの発見は,オルガノシリコン化学の理解と,新しい有機金属変換の発展に貢献します.
関連する概念動画
01:22Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.
03:08Hydroboration-Oxidation of Alkenes
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02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
02:40Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Introduction
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
02:15Preparation of Alcohols via Addition Reactions
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
01:19Aldehydes and Ketones to Alkenes: Wittig Reaction Overview
The Wittig reaction is the conversion of carbonyl compounds-aldehydes and ketones-to alkenes using phosphorus ylides, or the Wittig reagent. The reaction was pioneered by Prof. Georg Wittig, for which he was awarded the Nobel Prize in Chemistry.