キラル・サイクロペンタディニル・コバルト (III) 複合体は,高度にエナチオセレクティブの3d金属触媒C-H機能化を可能にします
Kristers Ozols1, Yun-Suk Jang1, Nicolai Cramer1
1Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland.
Journal of the American Chemical Society
|March 23, 2019
まとめ
新しいコバルト (III) 複合体は,キラルリガンドで効率的な非対称C-H機能化を可能にします. これらの触媒は,ダイヒドロアイソキノロン合成において高いエナチオセレクティビティを達成し,ロジウム (III) 方式を上回る.
科学分野:
- 有機金属化学
- 非対称な触媒
- 合成有機化学
背景:
- チラルのサイクロペンタディエニルリガンドは,金属触媒反応におけるステレオ化学の制御に不可欠である.
- 非対称C-H機能化は,効率的な分子合成の鍵となる戦略である.
- コバルトの触媒は ロージウムのような貴金属の 代替品として有望です
研究 の 目的:
- 三置換されたキラルサイクロペンタディニルリガンドを含む新しいコバルト (III) 複合体を合成し,特徴づけること.
- これらの新しいコバルト複合物の ステリックと電子の性質を調査する.
- 非対称なC−H機能化反応におけるその可能性を評価する.
主な方法:
- コバルト (III) 複合体の合成にキラルサイクロペンタディニルリガンドが用いられる.
- 合成された複合体のステリックおよび電子パラメータの詳細なマッピング.
- コバルト複合体を非対称C-H機能化反応の触媒として適用し,特にN-クロロベンザミドとアルケンの二酸化イソキノロン合成.
主要な成果:
- 新しい一連のコバルト (III) 複合体の合成と特徴づけに成功した.
- 複合体の非対称なC-H機能化を触媒化する有効性の実証.
- 優れたエナチオ選択性 (最大99. 5: 0. 5er) と高地域選択性 (高地域選択性) を得ている.
- この変換には既存のロジウム (III) ベースの方法よりも優れている.
- アルキルアルケンのような挑戦的な基板でも高い地域選択性とエナチオ選択性を示した.
結論:
- 開発されたコバルト (III) 複合体は,非対称なC-H機能化のための非常に効果的な触媒である.
- これらの複合物は,この反応クラスのロジウム (III) 触媒よりも重要な進歩を表しています.
- この方法論は価値あるダイヒドロイソキノロン製品への 堅牢で選択的な経路を提供する.
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