ケトンにアルキル基を非対称的に加える,実用的な触媒的加法
Celina García1, Lynne K LaRochelle, Patrick J Walsh
1P. Roy and Diane T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Journal of the American Chemical Society
|September 13, 2002
まとめ
この研究は,ケトンにエチル基を非対称的に加えるための新しい触媒的方法を提示し,高いエナチオ選択性を達成します. この画期的な発見は,キラル三次アルコールを合成するための実用的なアプローチを提供します.
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
- 有機金属化学 有機金属化学
背景:
- アルキルジンク反応剤をアルデヒドに非対称的に添加することが確立されています.
- ケトンに対する一般的で高度なエナチオセレクティブ性の高い触媒添加は,依然として課題です.
研究 の 目的:
- エチル基をケトンに非対称的に加えるための実践的な触媒を開発する.
- キラル三次アルコールの合成において高いエナチオセレクティビティを達成するために.
主な方法:
- カンファー硫ニル塩化物とトランス-1,2-ダイアミノサイクロヘキサンから新しい触媒が合成されました.
- 触媒前駆体はC2対称エクソダイアステロエーマーに還元された.
- 催化システムには,テトライスプロポキシドチタンとダイアルキルジンクを使用した.
主要な成果:
- 触媒システムは,エチル基をケトンにエナチオセレクティブで添加することを達成した.
- その結果,高エナティオメール過量 (一つを除いてすべて> 87% ee) を有する三次アルコールを分離した.
- 特殊な反応により2モル%の触媒を用いた99%eeの3次アルコールの73%が得られました.
結論:
- ケトンの非対称エチル化のための実用的で高度にエナチオセレクティブな方法が確立されました.
- 開発された触媒システムは,価値あるキラル三次性アルコールに効率的なアクセスを提供します.
- この方法は,ケトン添加物の非対称合成における重要なギャップを埋めます.
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