ゴールド交換:金 (III) -酸素結合に逆戻り可能な,形式的なエチレン挿入のメカニズム的研究
Eirin Langseth1, Ainara Nova, Eline Aa Tråseth
1Department of Chemistry and ‡Centre for Theoretical and Computational Chemistry (CTCC) Department of Chemistry, University of Oslo , P.O. Box 1033, Blindern, N-0315 Oslo, Norway.
Journal of the American Chemical Society
|June 20, 2014
まとめ
この研究は,金 ((III) 複合体がエチレンと反応し,新しい金-炭素結合を形成する方法を明らかにしています. アニオン安定化により,TFAやTFEのような酸性溶媒では反応速度が速い.
科学分野:
- 有機金属化学 有機金属化学
- ゴールド・カタリシス
- 反応メカニズム 反応メカニズム
背景:
- 金 ((III) 複合体は,触媒作用において有価であるが,オレフィンとの反応機構については,さらなる解明が必要である.
- リンガンド解離とオレフィン挿入を理解することは,効率的な金触媒反応の設計の鍵です.
研究 の 目的:
- エチレン.とAu (III) 複合体Au (OAc (F)) 2 (tpy) の反応機構を調査する.
- 反応速度と製品の選択性に影響を与える要因を決定する.
- 反応経路を理解する上で溶媒と計算方法の役割を探求する.
主な方法:
- 金 (III) 複合体の合成と特徴づけ
- リンガンド解離を監視するための核磁気共鳴 (19F NMR) スペクトロスコーピー.
- 製品構造を決定するためのX線結晶学.
- 密度関数理論 (DFT) 計算 (PBE0-D3) で,反応メカニズムを解明する.
主要な成果:
- Au (III) 複合体は,アセテートリガンドの可逆解離を経験する.
- エチレンは正式にAu-O結合に挿入し,新しい金-炭素と酸素-炭素結合を形成します.
- 反応速度は,二塩基メタン (CH2Cl2) に比べて,三酸 (TFA) と三エタノール (TFE) で著しく速い.
- DFTの計算は,エチレンが黄金の中心を攻撃することで開始された関連置換メカニズムを示唆しています.
- 製品の選択性は,観測された同位体を好む運動的および熱力学的好みによって支配されます.
結論:
- 反応は,関連置換機構を経由し,オレフィン挿入が続く.
- TFAやTFEのような溶媒は,脱出するアセテートリガンドを安定させることで反応を加速します.
- この研究は,金 ((III) 触媒によるオレフィン機能化に関する詳細なメカニズム的洞察を提供します.
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