オレフィンエポキシデーションとアルケンの水酸化反応における単核非ヘム高スピン鉄 (III) -アシルペロキソ複合体
Bin Wang1, Yong-Min Lee1, Martin Clémancey2
1Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea.
Journal of the American Chemical Society
|January 28, 2016
まとめ
単核非ヘム鉄 (III) -アシルペロキソ複合体は,オレフィンとヒドロキシラートアルカンを高精度で効率的にエポキシジングする. これらの鉄複合体は強力な酸化物質として作用し,O−O結合の割れ方による炭化水素酸化を促進します.
科学分野:
- 無機化学
- 有機金属化学
- カタリシス
背景:
- 非ヘム鉄複合体は,生物無機化学と触媒に不可欠である.
- 高スピンの鉄 (III) -アシルペロキソ種の反応性を理解することは,新しい酸化触媒の開発の鍵です.
- オレフィンエポキシデーションとアルカン水酸化は,有機合成における基本的な変換である.
研究 の 目的:
- 単核非ヘム高スピン鉄 (III) -アシルペロキソ複合体を合成し,特徴づけること.
- オレフィンエポキシデーションとアルカン水酸化におけるこれらの複合体の触媒的活性を調べる.
- 反応メカニズムを解明し,活性酸化物種を特定する.
主な方法:
- 鉄 (III) -アシルペロキソ複合体の合成とスペクトル学的特徴付け.
- 様々なオレフィンとアルカンを用いた触媒研究
- 運動同位体効果 (KIE) の測定
- ステレオ化学とエナチオ選択性分析
- 同位体ラベル (H2~18) Oを用いたメカニズム調査.
主要な成果:
- オレフィンエポキシデーションで高いステレオ,化学,およびエナンチオ選択性が得られた.
- サイクロヘクセンエポキシデーションにおける1. 0の運動同位体効果 (KIE) は,C=CエポキシデーションがC-H活性化よりも優れていることを示している.
- チラルの鉄 (III) - アシルペロキソ複合体は,高いエナチオ選択性を持つエポキシドを産生し,酸化剤としてアシルペロキソ種を特定した.
- アルケンの水酸化は低温 (−40°C) で効率的に発生し,地域とステレオ選択性が高い.
- 機械学的研究により,C−H結合の活性化が速度決定因子であり,アルコールの産物の源としてアシルペロキソ酸素が確認された.
結論:
- 単核非ヘム高スピン鉄 (III) -アシルペロキソ複合体は,炭化水素酸化のための強力な酸化物質である.
- これらの複合体は,エポキシデーションと水酸化反応の両方で高い選択性を示す.
- 鉄 (III) - アシルペロキソ種は,鉄オキソではないが,活性なエポキシジング剤である.
- このメカニズムは,アクティブな酸素化種を生成するために,アシルペロキソリガンドのO-O結合の割れ目を伴う.
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