シリリウム触媒を用いたアリファティックな炭素-ハロゲン結合の水素デハロゲン化およびその他の水素デハロゲン化
Christos Douvris1, C M Nagaraja, Chun-Hsing Chen
1Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, USA.
Journal of the American Chemical Society
|March 12, 2010
まとめ
新しい触媒は,C-F,C-Cl,C-Br結合の効率的な水分除を,トライアキルシランを用いて可能にします. この反応は,選択的にC ((sp ((3)) -ハロゲン結合を標的とし,CF ((4) を除き,広範囲の基板範囲を提供します.
科学分野:
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
- 合成有機化学 合成有機化学について
背景:
- ハイドロデハロゲネーションは,有機合成における重要な変化である.
- 既存の方法は,しばしば選択性が欠けているか,厳しい条件を必要とする.
- 強い炭素-ハロゲン結合,特にC-F結合を分裂するための効率的な触媒の開発は,依然として課題です.
研究 の 目的:
- さまざまな炭素-ハロゲン結合の水分分解のための新しい触媒システムを開発する.
- これらの触媒の範囲と限界を調査し,C-F,C-Cl,C-Br結合割れに焦点を当てます.
- 異なるハロゲン基板に対する触媒システムの反応性と選択性を理解する.
主な方法:
- ハロゲン化カルボランアニオンを触媒として用いたトライアキルシリリウムカチオン等価剤を用いた.
- トライアルキリシランを,水解塩素化反応のステキオメトリック反応剤として使用する.
- X線 difraksionを含むスペクトロスコーピカルおよび結晶学的技術を使用して,触媒システムと反応製品を特徴付けます.
主要な成果:
- 触媒系は,C-F,C-Cl,C-Br結合の水素分解を効率的に促進し,C ((sp ((3)) -ハイブリッド化された炭素のみで発生します.
- アルキルフッ化物やベンゾトリフッ化物を含む幅広いC-F結合を含む基板は反応するが,CF (−4) は反応しない.
- 様々なアルキル塩化物と原発アルキルブロミドで,それぞれ水酸化塩化物と水酸化ブロミンが示されました.
- 競争実験では,原発アルキルハリドの軽いハロゲンに対する運動的好みを明らかにしたが,C ((6) F ((5) CX ((3)) システムでは,ヒドロデクロリネーションよりもヒドロデフローリネーションが速い.
結論:
- トリアルキルシリウムカチオン/ハロゲン化カルボランアニオン系は,水解ハロゲン化のための有効で安定した触媒を代表しています.
- 触媒は,C ((sp ((3)) -ハロゲン結合を標的にし,さまざまなハロゲンに対して異なる反応性を示すユニークな選択性を示す.
- この方法論は,合成化学者にとって,特に困難な基質の脱フッ素化のために,貴重な新しいツールを提供します.
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