安定したフォスフォニウムシロイリドで,シロ-ウィッティッグの反応剤として反応性がある
David Gau1, Tsuyoshi Kato, Nathalie Saffon-Merceron
1Universite de Toulouse, UPS, LHFA, and CNRS, LHFA UMR 5069, F-31062 Toulouse, France.
Journal of the American Chemical Society
|June 6, 2009
まとめ
研究者は,安定したフォスフォニウムシライリド,フォスフォニウムイリドのシリコンアナログを合成しました. この新しい化合物は,シラ-ウィティッグ反応剤として作用し,カルボニルと新しい化学反応を可能にします.
科学分野:
- オーガノシリコン化学 化学
- メイングループ 化学
- 合成有機化学 合成有機化学について
背景:
- リン酸イリドは有機合成において極めて重要であり,通常は炭素を含みます.
- Fosphonium ylidesのシリコンコンゲネアは,以前は一時的な中間物質と考えられていた.
- シリコンベースのイリドの安定性と反応性に関する理解は限られている.
研究 の 目的:
- 安定したフォスフォニウムシライリドを合成し,特徴づけること.
- 合成されたシライリドの構造的および電子的性質を調査する.
- 合成反応剤としてのフォスフォニウムシライリドの反応性を調査する.
主な方法:
- フォスフォニウムシライリドの合成.
- 構造的決定のためのX線結晶学.
- 特徴付けのための光譜分析 (NMR,IR)
- カルボニル化合物の反応性に関する研究.
主要な成果:
- 驚くほど安定したフォスフォニウムシライリドの合成が成功しました.
- X線構造は,長いSi-P結合とピラミッド化されたシリコンセンターを明らかにし,弱いP-Si pi相互作用を示唆しました.
- シライリドは,核愛性シリコン中心を持つアルファ,ベータ,両性特性を示した.
- この化合物は,カルボニル誘導体によるシラ-ウィティッグ反応剤として効果的に機能した.
結論:
- 安定したフォスフォニウムシロイリドが合成され,以前の仮定に異議を唱える.
- 独特の電子構造は,特にシラ-ウィティッグ反応において,新しい反応性を可能にします.
- この発見は,オルガノシリコン化学と合成方法論のための新しい道を開く.
関連する概念動画
Aldehydes 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.
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
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Carboxylic Acids to Acid Chlorides
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α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the bromine molecule...
SN2 Reaction: Transition State
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
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