単電子還元によって可能になったエナミドのコバルト触媒による非対称な水素化
Max R Friedfeld1, Hongyu Zhong1, Rebecca T Ruck2
1Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Science (New York, N.Y.)
|May 26, 2018
まとめ
新しい亜鉛活性化法により,コバルト・フォスフィン触媒を用いた効率的な非対称な水素化が可能である. レベチラセタムのような重要な薬剤を 合成するために 費用対効果の高い代替手段を 提供しています
科学分野:
- カタリシス
- 有機金属化学
- アシンメトリック・シンセシス
背景:
- 高価な金属に匹敵する性能を持つ第一列の移行金属触媒の開発は極めて重要です.
- 一電子化学は 潜在的可能性を秘めていますが 解消の課題に直面しています
研究 の 目的:
- 一電子化学を用いた触媒の活性化モードを特定する.
- トランジション金属触媒の第1列の解消経路を克服する.
- 非対称な水素化のための効率的なコバルト-フォスフィン触媒を発見するために.
主な方法:
- 高通量スクリーニングと互換性のある亜鉛活性化法を使用した.
- コバルトとフォスフィンの組み合わせは,機能化されたアルケンの非対称な水素化のためにスクリーニングされた.
- (R,R) -Ph-BPEとコバルト塩化物から最適化された触媒を準備した.
主要な成果:
- 多くのコバルト-フォスフィンの組み合わせが非対称な水素化のために特定されました.
- 最適化された触媒は,プロティック媒体で高い活性とエナチオ選択性を示した.
- 200グラムスケールで0. 08モル%の触媒負荷でレベチラセタムの非対称合成が成功しました.
- ステイキオメトリック研究では,コバルト (II) が亜鉛によって促進され,安定したコバルト (I) 種に1電子減少することが示された.
結論:
- 亜鉛活性化方法は,高活性で選択的なコバルト・フォスフィン触媒の発見に有効である.
- このアプローチは,土に豊富な金属を用いて薬剤の効率的な非対称合成を可能にします.
- コバルトの活性化に関するメカニズム的な洞察は,将来の触媒設計のための基盤を提供します.
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