オキシカルベニウムイオンへのエナチオセレクティブのチオウレア触媒添加物
Sarah E Reisman1, Abigail G Doyle, Eric N Jacobsen
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Journal of the American Chemical Society
|May 16, 2008
まとめ
チラル尿素とチオウレア触媒は,オキシカルベニウムイオンのエナチオ選択反応を可能にします. これらの触媒は,シリルケテンアセタルの1-クロロアイソクロマンへの置換を促進し,三次ベンジルアミド誘導体は最良の結果を示しています.
科学分野:
- 有機化学 オーガニック・ケミストリー
- アシンメトリック・カタリシス
背景:
- オキシカルベニウムイオンは,有機合成における重要な中間物質である.
- その反応に対するエナチオセレクティブ・メソッドの開発は,キラル分子を作る上で極めて重要です.
研究 の 目的:
- オキシカルベニウムイオンを含む非対称な触媒反応を報告する.
- キラル尿素およびチオウレア誘導体のエナチオセレクティブ変換の触媒としての使用を調査する.
主な方法:
- 単純でキラルな尿素とチオウレア誘導体を触媒として利用した.
- シリルケテンアセタルの1-クロロアイソクロマンへの置換反応を調査した.
- 触媒構造を分析し,特に三次ベンジルアミド基を持つものを分析した.
主要な成果:
- キラル尿素およびチオウレア誘導体によって触媒化された,成功しているエナンチオセレクティブ置換反応が実証されています.
- 最も高いエナチオ選択性を提供する三次ベンジルアミド含有触媒を特定しました.
- 最適な触媒構造は,エナンチオ濃縮された2 - アリルピロリジン誘導体から導出されていることが判明しました.
結論:
- チラル尿素およびチオウレア誘導体は,非対称オキシカルベニウムイオン化学の効果的な触媒である.
- キラル触媒によるアニオン結合は,反応性オキシカルベニウムイオン中間物質を生成するように提案されています.
- エナチオセレクティブ合成は,ピロリジン構造から派生したカスタマイズされたキラル触媒を使用して達成できます.
関連する概念動画
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Direct addition products are formed faster owing to...
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