アルカンボリレーションのボロン補助シグマ結合転移経路の実験的および計算的証拠
Charles Edwin Webster1, Yubo Fan, Michael B Hall
1Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, USA.
Journal of the American Chemical Society
|January 23, 2003
まとめ
金属複合体からのCOリガンドの光エジェクションにより,C-H結合を活性化する中間物質が生成されます. ボロン・ボロンは,
科学分野:
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
- C-H アクティベーション
背景:
- CpM(CO) n+1BR2複合体からのCOリガンドの光エジェクションにより,16電子の中間物質が生成されます.
- これらの中間物質は,周期性ダイオキシボリルリガンドを特徴とし,C-H結合の活性化が可能である.
研究 の 目的:
- ディオキシボリル移行金属複合体によって開始されるC-H結合活性化のメカニズムを調査する.
- C−H活性化プロセスにおけるダイオキシボリルリガンドの空のp軌道における役割を明らかにする.
主な方法:
- フォトエジェクションとC-H機能化に関する実験研究.
- 反応機構と電子効果を調査するための理論的計算.
主要な成果:
- 16電子のダイオキシボリル中間体による効率的で地域選択的なC-H結合活性化が実証されています.
- ボロン原子の空のp軌道が,C−H活性化に決定的であることを示した.
- そのメカニズムは,金属介的シグマ・ボンド・メタテシスによる,ボロン補助によるメタテシスであると特定した.
結論:
- ボロンの空のp軌道では,金属からの電子密度を受け入れることで,移行状態と中間物質を安定させます.
- このユニークなメカニズムは,ボロンへの水素移転と,その後のアルカンの機能化を促進します.
- 観察された化学反応は,アルキルまたはアリルリガンドを含むCpM(CO) n複合体と,以前に報告された複合体とは異なる.
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