Au (I) -触媒化水利化における地域選択性の静電制御
Vivian M Lau1, William C Pfalzgraff1, Thomas E Markland1
1Department of Chemistry, Stanford University , 337 Campus Drive, Stanford, California 94305, United States.
Journal of the American Chemical Society
|February 23, 2017
まとめ
イオンペアリングによる触媒反応の制御は,選択的に産物形成を誘導する. カウンターイオンと触媒の間の静電相互作用は,移行状態を調整し,領域選択性を最大12倍に高めます.
科学分野:
- カタリシス
- 有機化学
- コンピュータ化学
背景:
- 競合する反応経路は,しばしば異なる電荷分布を持つ移行状態を特徴とする.
- 反応の選択性を制御するためにこれらの電荷の違いを利用することは困難です.
- 触媒複合体のイオンペアリングは静電制御のための潜在的なメカニズムを提供します.
研究 の 目的:
- イオンペアリングが金で触媒化された水酸化反応における地域選択性への影響を調査する.
- 移行状態のエネルギーと製品の配分にどのように影響を与えるかを理解する.
- イオンペアリング効果の調節における溶媒介電体の役割を探求する.
主な方法:
- カチオンのAu (I) 触媒を用いた3置換フェニルプロパルギルエーサーの水酸化実験.
- SbF6対離子とのイオンペアリングを制御するための溶媒介電流の系統的な変化.
- 移行状態のエネルギー差 (ΔΔE‡) を決定する密度関数理論 (DFT) の計算.
主要な成果:
- 2H-クロメンの形成の地域選択性は,溶媒のダイエレクトリックによって最大12倍に変化した.
- DFT計算は,Δ(ΔΔE‡) を分析することで,実験選択性の変化を正確に予測した.
- イオンペアリングは,より大きな電荷分離で移行状態を優先的に安定させます.
結論:
- カウンテリオンとのイオンペアリングは,触媒の領域選択性を制御するために効果的に使用できます.
- 溶媒の介電はイオンペアリングを強制し,複雑な溶媒の相互作用に影響を与えるという二重な役割を果たします.
- この研究は,静電制御に基づく選択的触媒システムの設計のための枠組みを提供します.
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