高効率のエナチオセレクティブ内分子C ((sp3) -Hアミデーションのための非C2対称キラル-at-ルテニウム触媒
Zijun Zhou1, Shuming Chen2, Yubiao Hong1
1Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Strasse 4 , 35043 Marburg , Germany.
Journal of the American Chemical Society
|November 22, 2019
まとめ
遠隔のN-ヘテロサイクルカルベンリガンドを備えた新しいキラルルテニウム触媒は,効率的な分子内C ((sp3) -Hアミデーションを可能にします. 非C2対称な触媒は,C2対称な対称性を上回る高いエナチオ選択性を持つキラルガンマラクタムを生成する.
科学分野:
- 有機金属化学
- キャタリシス
- 非対称合成
背景:
- ルテニウム触媒は有機合成に不可欠です
- キラル触媒は,エナチオ選択的変換を可能にします.
- N-ヘテロサイクリックカルベン (NHCs) は,触媒における多用途リガンドである.
研究 の 目的:
- チラルルテニウム触媒の新種を導入する
- これらの複合体の分子内C ((sp3) -Hアミデーションにおける触媒的活性を調べる.
- 金属中心の立体化学が触媒的な結果に与える役割を理解する.
主な方法:
- ピリジリデンリモートN-ヘテロサイクリックカルベン (rNHC) リガンドによるキラルルテニウム複合体の合成.
- 1,4,2-ダイオクサゾール-5-オンの分子内C ((sp3) -Hアミデーションの触媒試験
- キラルクロマトグラフィを用いたエナティオメール比率の決定
- 反応メカニズムを解明するための密度関数理論 (DFT) の計算.
主要な成果:
- 7-メチル-1,7-フェナントロリニウムヘテロサイクルによって合成されたキラルルテニウム触媒の新種が合成された.
- 非C2対称のキラル-アット-ルテニウム複合体は,内分子C ((sp3) -Hアミデーションの高触媒活性を示し,キラル・ガンマ-ラクトームを99:1まで生成した.
- 触媒の負荷は0.005モル% (最大11,200トン) であった.
- C2対称性ダイアステロエーマーでは,主として望ましくないカーティウス型再配置が行われました.
- DFTの計算は,非C2対称な触媒の優れた反応性の起源を明らかにした.
結論:
- 比較的金属中心のステレオ化学は,C ((sp3) -Hアミデーションにおける高いエナチオ選択性の達成に不可欠である.
- 非C2対称性のあるキラルルテニウム触媒は,キラルガンマラクタムの合成に前例のない効率性を提供します.
- 開発された触媒システムは,非対称合成のための貴重なツールを提供します.
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