Cu ((II) -アレンとボロン酸間の酸素化クロスカップリング反応をエアロビック条件下でメカニズムの研究
Qian Zhang1, Yang Liu1, Ting Wang2
1MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China.
Journal of the American Chemical Society
|April 10, 2018
まとめ
この研究は,アリル銅 (II) が,アリル銅 (III) ではなく,銅で触媒化されたクロスカップリング反応の主要な中間物質であることを明らかにしている. このメカニズムの理解は,新しい銅触媒反応の設計に役立ちます.
科学分野:
- 有機金属化学
- キャタリシス
- 有機合成
背景:
- 銅の塩は豊富で 安価で 有害性が低い 代用品です
- 銅触媒反応はC-CとC-ヘテロ原子結合形成に広く使用されているが,そのメカニズムは不明である.
- アザカリックス[1]アレン[3]ピリジンマクロサイクルは,メカニズム研究のために明確に定義されたアリル銅 (II) とアリル銅 (III) コンプレックスを提供します.
研究 の 目的:
- 空気を酸化剤として使用したアレンとボロン酸間のCu (II) 触媒による酸化クロスカップリングの反応機構を解明する.
- 触媒サイクルに含まれる 有機金属中間物質を特定する.
- 新しい銅触媒反応の合理的な設計のための洞察を提供するために.
主な方法:
- アリルボロン酸によるステキオメトリック反応
- スペクトロスコーピテクニック:XPS,EPR,1H NMR,HRMS,UV-vis
- 製品と銅の種を分離し,定量化する.
- 電子構造とエネルギーの計算分析
主要な成果:
- アリル銅 (II) が反応性中間物質として特定され,アリル銅 (III) ではない.
- 提案されたメカニズムは,電離性メタリング,トランスメタリング,Cu (III) とCu (I) を形成する酸化還元反応,および還元性除去を含む.
- Cu ((I) 種は酸素によってCu ((II) に再酸化され,次のサイクルのための触媒を再生します.
結論:
- クロスカップリング反応におけるアリル銅 (II) 化合物の反応性は明らかにされている.
- Cu (II) 誘導された酸化クロスカップリングの詳細な触媒サイクルが提案されています.
- この機械的理解は,新しい銅触媒合成方法論の開発に価値があります.
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