ケレーションアシスト,銅 (II) アセテート加速度アジドアルキンサイクル添加のメカニズムに関する実験調査
Gui-Chao Kuang1, Pampa M Guha, Wendy S Brotherton
1Department of Chemistry and Biochemistry, Florida State University, Tallahassee, 32306-4390, United States.
Journal of the American Chemical Society
|August 4, 2011
まとめ
この研究では,シェラ化アジドと銅 (II) アセテートがアジド-アルキンサイクル添加反応をどのように加速するか明らかにしています. メカニズムモデルでは,銅 ((I/II) /アジド相互作用と混合価二核銅種が触媒作用において果たす重要な役割を強調しています.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- 反応メカニズム 反応メカニズム
背景:
- 銅で触媒化されたアジド-アルキンサイクル添加 (AAC) は,重要な"クリック化学"反応です.
- AAC反応における銅(II) アセテート (Cu(OAc) ((2)) とのケラートアジドの高い反応性は,メカニズム的な説明を必要としています.
研究 の 目的:
- チラートアジドを含む加速銅 (((II) 媒介のAAC反応のメカニズムモデルを策定する.
- 異なる酸化状態における銅イオンの役割と,反応経路における溶媒の影響を明らかにする.
主な方法:
- 反応モニタリングのための光と (1) H NMRアッセイの開発.
- 溶剤の運動性同位体効果とプレミクシング実験を含む運動学的研究.
- Cu (((OAc)) (((2) を含むシェラ化アジドのX線結晶構造分析.
主要な成果:
- 銅 (II) から銅 (I) にメタノール (メタノールの酸化) とアセトニトリル (アルキンの酸化性ホモカップリング) に変換するための明確な誘導反応を特定しました.
- 決定された運動順序で,銅イオンとケラートアジドの間の急速な均衡前相互作用が明らかになった.
- アルキン酸化性ホモカップリングとAACの間で,バイメタリック経路と塩基触媒を伴うメカニズム的な相乗効果が観察されました.
結論:
- 混合バレンスの二核銅種 (+2と+1) は,2つの銅センターの役割が異なるため,非常に効率的な触媒として提案されています.
- 銅 (I/II) /アジドの相互作用の運動的重要性を強調し,銅 (I/II) /アルキンの相互作用に関する既存の焦点を補完しました.
- 素早く Cu ((OAc) ((2)) を媒介する AAC 反応と ケラートアジドのメカニズム的基礎を提供し,触媒に実用的な影響を及ぼした.
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