アルキンのコバルト媒介の周期的および線形2:1コリゴメリゼーションとアルケンのコリゴメリゼーション: DFT研究
Vincent Gandon1, Nicolas Agenet, K Peter C Vollhardt
1Université Pierre et Marie Curie-Paris 6, Laboratoire de Chimie Organique (UMR CNRS 7611), Institut de Chimie Moléculaire (FR 2769), case. 229, 4 place Jussieu, F-75252 Paris Cedex 05, France. gandon@ccr.jussieu.fr
Journal of the American Chemical Society
|June 29, 2006
まとめ
アルキンとアルケンのコバルト触媒 [2+2+2] サイクル添加は,DFTを用いて研究されました. コバルト-炭素結合へのアルケンの挿入は,重要な中間物質を形成し,サイクロヘキサディエンまたはヘキサトリエンにつながり,2つの状態の反応性が潜在的に関与しています.
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
- コンピューティング・ケミストリー
背景:
- コバルト複合体は,アルキンとアルケンの [2+2+2]サイクル添加を触媒化する.
- 反応メカニズムの理解は,触媒の設計と最適化に不可欠です.
研究 の 目的:
- 2つのアルキンと1つのアルケンのコバルト媒介 [2+2+2]サイクロアディションのメカニズムを解明する.
- CpCo複合体の1,3-サイクロヘキサディエンとヘキサトリエンの形成を調査する.
- 触媒サイクルにおけるスピン状態と2状態反応性の役割を調査する.
主な方法:
- 密度関数理論 (DFT) の計算が採用されました.
- 高スピンと低スピンの潜在エネルギー表面の分析.
- 最低エネルギー交差点 (MECP) を含む,主要な中間物質と移行状態の特定.
主要な成果:
- アルケンの組み込みは,Co-Cシグマ結合への挿入を経由して進み,7つ構成の金属サイクル中間物質を形成します.
- この中間物質は,CpCo複合体のサイクロヘクサディエンまたはヘクサトリエン製品につながる可能性があります.
- ヘクサトリエンの形成はエチーンによって促進され,芳香的二重結合によるC-H活性化を含むことができる.
- シングレットコバルト種は,トリプル種よりも運動的に優れているが,両方のスピン表面を含む2つの状態の反応性が提案されている.
結論:
- このメカニズムは,アルキンがコバルト-炭素結合に挿入され,アルキンのサイクロトリメリゼーションとは異なる.
- 7基の金属サイクルは,周期性オリゴーマーと線形オリゴーマーの両方の形成を説明する重要な中間物質です.
- シングレット・トリプレットの混合を含む2状態の反応性は,MECPの発見によって支持され,重要な役割を果たす可能性があります.
関連する概念動画
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01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
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