水素原子を単核銅で抽象化するメカニズム:水素原子の移転か,協調した陽子結合電子の移転か?
Mukunda Mandal1, Courtney E Elwell1, Caitlin J Bouchey1,2
1Department of Chemistry, Minnesota Supercomputing Institute, Chemical Theory Center, and Center for Metals in Biocatalysis , University of Minnesota , 207 Pleasant Street SE , Minneapolis , Minnesota 55455 , United States.
Journal of the American Chemical Society
|October 17, 2019
まとめ
二酸化炭素アミドリガンドを持つ銅 (III) 複合体は,水素原子移転 (HAT) および協調された陽子結合電子移転 (cPCET) 機構を通じてX-H結合を活性化します. 反応性は銅の機能性と基板によって異なるが,複合体1が最も反応性がある.
科学分野:
- 協調化学
- 有機金属化学
- カタリシス
背景:
- 銅 (III) -酸素複合体は,X-H結合 (X = C,O) を生体模倣的に活性化することが知られている.
- リガンドフレームワークであるN,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis),N,N'-bis (N,N'-bis) は,高値銅種を安定化するのに重要な役割を果たしている.
- X-H結合の活性化メカニズムを理解することは,新しい触媒プロセスを開発する上で鍵となる.
研究 の 目的:
- メタクロフェニル基を持つ新しい銅 (III) 複合体,LCu (III) -O2CAr1 (3) を合成し,特徴づけること.
- 複合体1,2,3のX-H結合活性性を調べ,比較する.
- 観察されたX-H結合の活性化に関与するメカニズム的経路 (水素原子移転対協調型陽子結合電子移転) を解明する.
主な方法:
- 銅 (III) 複合体の合成と特徴付け
- 様々なO-HとC-Hを含む基板との反応速度を決定するための運動研究.
- 水素原子移転 (HAT) と協調された陽子結合電子移転 (cPCET) を区別するための理論的ツールの適用.
主要な成果:
- 複合体1がX- H結合の活性化において最も高い反応性を示し,複合体3が続いており,複合体2は非反応的であった.
- 動力学的測定は,明確な速度の違いを持つ二次反応動力学を示した.
- HATとcPCETの両方のメカニズムは,基質と銅複合体の構造によって異なるX- H結合活性化経路として特定されました.
結論:
- X-H結合の活性化における正式な銅 (III) 複合体の反応性は,酸化能力と特定の機能化メカニズムの両方によって影響を受けます.
- この研究は,さまざまなX-H結合活性化が可能である反応性銅 (III) 種をサポートするディカルボキシアミドリガンドの汎用性を強調しています.
- この研究は,生体模倣と触媒の応用に関連する,銅媒介結合活性化のメカニズム的なニュアンスについての洞察を提供します.
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