触媒的に非対称なα-イミノール再配置:新しいキラルプラットフォーム
Xin Zhang1, Richard J Staples, Arnold L Rheingold
1Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
Journal of the American Chemical Society
|September 24, 2014
まとめ
研究者らは,α-ヒドロキシイミンをα-アミノケトンに変換する新種のジルコニウムベースのキラル触媒を発見した. この高度なエナチオセレクティブ性の高い触媒は,様々な基板に対して優れた収量とエナチオメール過剰 (ee) を達成します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- アシンメトリック・シンセシス
背景:
- α-ヒドロキシイミンのα-アミノケトンへの再配置は,有機合成における重要な変換である.
- この反応,特に1,2-炭素シフトを含む効率的なキラル触媒の開発は,依然として重要な課題です.
研究 の 目的:
- 1,2-炭素シフトによるα-ヒドロキシイミンのα-アミノケトンへの非対称的な再配置を媒介できる最初のキラル触媒を特定すること.
- この変換に最も効果的なものを見つけるために,非対称な触媒の多様なライブラリをスクリーニングする.
主な方法:
- VAPOL,VANOL,およびその誘導体を含む19種類の非対称な触媒のスクリーニング.
- X線 difraksionを用いた最も効果的な触媒の詳細な特徴.
主要な成果:
- VAPOL,VANOL,および7,7'-(t) Bu2VANOLのアルミナート複合体は,88%のエナティオメール過剰 (ee) を達成し,有意な触媒活性を示した.
- VANOLのジルコニウム複合体は最適の触媒として出現し,ほとんどの基板に対して97%から>99%のEEを生成しました.
- X線微分分析により,ジルコニウム触媒は3つのVANOLリガンドと2つの陽子化されたN-メチルイミダゾールを含むホモレプティック複合体であることが明らかになった.
結論:
- α-ヒドロキシイミンの非対称的な再配置のために,新しく非常に効果的なジルコニウムベースのキラル触媒が開発されました.
- この触媒は,高いエナチオ選択性を持つα-アミノケトンの合成を大幅に促進し,有機化学者に貴重なツールを提供します.
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