In Situ メチレンキャピング:効率的なステレオレテンティブ触媒性オレフィンメタテシスの一般的な戦略. 生物学的活性化合物の合成に関する概念,方法論的含意,応用
Chaofan Xu1, Xiao Shen1, Amir H Hoveyda1
1Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.
Journal of the American Chemical Society
|July 28, 2017
まとめ
Z-ブテンでインシットメチレンキャピングは,ステレオ選択的オレフィン転移を拡大する. この実用的な戦略は,堅固なルテニウム触媒を用いた多様な変換の効率とZ選択性を高めます.
科学分野:
- 有機化学
- カタリシス
- 合成化学
背景:
- オレフィンメタテシスは強力な合成ツールですが,その範囲とステレオ選択性はしばしば制限されています.
- メタテシス反応において,特に末端アルケンの場合,高いZ選択性を達成することは,依然として課題である.
- メチリデンの主要中間物質の安定性は,触媒システム全体で一般的な問題である.
研究 の 目的:
- 触媒制御型ステレオ選択性オレフィンメタテシスを強化するために,実用的で広く適用可能な in situ メチレンキャピング戦略を導入する.
- 簡単に入手可能な材料で反応を可能にすることで,オレフィン転移の範囲を拡大する.
- 既存の方法と比較して反応効率とZ選択性を改善する.
主な方法:
- 商業的に利用可能なZ-ブテンをインシットメチレンキャピング剤として利用する.
- 堅牢でアクセス可能なルテニウムベースのディチオラート触媒を使用しています.
- 様々な機能化されたオレフィンとダイエンで交差転移と環閉転移反応を行う.
主要な成果:
- in situ メチレンキャピング戦略は,Z選択性 (90: 10から> 98: 2 Z: E) と様々な基板とのクロスメタテシスの効率を大幅に改善しました.
- 原油クラッキングからのZ-E-ブテン混合物を使用しても,変換は非常に効率的でステレオ選択的でした.
- 環閉メタテシスにより,優れたZ選択性 (96:4-98:2 Z:E) を有する14〜21基のマクロサイクルアルケンが得られた.
- 同じルテニウム触媒は,交差転移と環閉転移の両方に変更なしに有効でした.
結論:
- 局所メチレンキャピングは,オレフィン転移の範囲を拡大し,ステレオ選択性を改善する汎用的な戦略です.
- このアプローチは,生物学的活性化合物やストレントマクロサイクルを含む複雑な分子の効率的な合成を可能にします.
- この方法は,メチリデン複合体の安定性の限界を克服し,ステレオ定義オレフィンを事前に合成する実用的な代替案を提供します.
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