トリフローロメチル群は,形状安定剤と探査機としての作用: cinchonaのアルカリド基板の形状分析
G K Surya Prakash1, Fang Wang, Martin Rahm
1Loker Hydrocarbon Research Institute, Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Journal of the American Chemical Society
|July 1, 2014
まとめ
キニジンにCF3群を加えると,フッ素NMRを用いたシンホーナ・アルカロイド構成の研究が可能になる. 経験的な溶解モデルは,溶媒の効果を正確に予測し,反応性研究を支援します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 物理化学 物理化学
- スペクトル顕微鏡検査です.
背景:
- シンコナ・アルカロイドは,形状的に柔軟な支架である.
- 構成的行動の調査は,それらの性質と反応性を理解するために重要である.
- フッ素-19核磁気共鳴 (19F NMR) スペクトロスコピーは,形状分析のための敏感な探査機を提供します.
研究 の 目的:
- シンチョナのアルカロイド構成に対する溶媒の影響を予測する理論的 (PCM) および経験的 (Kamlet-Taft) 溶解モデルの正確性を評価する.
- 様々な溶媒におけるキニジンと9-エピキニジンの構成的振る舞いを調査する.
- シンコナアルカロイドの反応性における溶媒誘発型変化の役割を明らかにする.
主な方法:
- 形状の安定性を高めるために,C9位置にCF3群を配置したキニジンの改変.
- 19F NMRスペクトロスコーピーを用いて,異なる溶媒における構成分布を決定する.
- 線形自由エネルギー関係 (LFER) 方法を適用して溶解モデルを評価する.
- カルプラス型方程式を用いて,構成分析を行う.
- 溶剤依存反応性を研究するためのモデルSN2反応を提示する.
主要な成果:
- CF3群の導入は,シンコナ・アルカロイド・スキャフォルドの構成的相互変換の障壁を大幅に増加させた.
- 経験的溶解モデル (Kamlet-Taft) は,溶媒がコンフォームに与える影響を正確に予測した.
- 理論的なPCM溶解モデルは,この研究で比較的低い信頼性を示した.
- キニジンと9-epi-キニジンのコンフォーム行動は,経験的モデルとKarplus方程式を使用して成功裏に調査されました.
結論:
- フッ化物-19 NMRは,シンコナのアルカロイド構造を研究するための強力なツールであり,特にCF3グループで改変された場合です.
- 経験的な溶解モデルは,これらのシステムに対する溶媒の影響を予測するのに信頼性があります.
- 溶剤によって引き起こされる形状の変化は,モデルSN2反応で示されているように,シンコナアルカロイドの反応性において重要な役割を果たします.
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