バイサイクルエポキシオニウムイオンに対する分子内加減反応の構造/反応性の関係を定義するための実験的および計算的アプローチ
Shuangyi Wan1, Hakan Gunaydin, K N Houk
1Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
Journal of the American Chemical Society
|June 6, 2007
まとめ
酸化分裂反応ではオキシカルベニウムイオンが生成され,バイサイクル型エポキシオニウムイオンが生成されます. これらのイオンの構造は,サイクライゼーション反応がエンドクローズまたはエクソクローズを好むかどうかを決定し,サイクリックオリゴエテルを生成します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 合成化学 合成化学とは
- コンピューティング・ケミストリー
背景:
- 循環性オリゴエッターは,天然製品や医薬品における重要な構造モチーフです.
- 複雑な周期性オリゴエーテルを効率的に合成することは,有機化学における課題です.
研究 の 目的:
- オキシダティブ分裂反応を用いてオキシカルベニウムイオンを生成する方法を研究する.
- バイサイクルエポキシオニウムイオンの形成と反応性を研究する.
- サイクル反応におけるステレオ選択性を制御する要因を理解する.
主な方法:
- オキシダティブ割れ反応は,オキシカルベニウムイオン生成のためのものです.
- オキシカルベニウムイオンの反応は,付着したエポキシドと起こる.
- B3LYP/6-31G ((d)) メソッドを用いた計算研究.
主要な成果:
- オキシカルベニウムイオンは,ペンデントエポキシドと反応して,バイサイクルエポキシオニウムイオンを形成する.
- バイサイクルエポキシオニウム中間物の構造は,エクソ対エンドサイクライゼーションの選択性を著しく影響する.
- Bicyclo[4.1.0]中介物質は内閉を好み,bicyclo[3.1.0]中介物質は外閉を好む.
- 計算分析は,移行状態のエネルギーと選択性の起源についての洞察を提供した.
結論:
- オキシダティブ・クリバージは,サイクルオリゴイザー合成のためのバイサイクルエポキシオニウムイオンへの有効な経路を提供します.
- サイクリングのステレオ化学的結果は,バイサイクルの中間構造に基づいて予測できます.
- 計算化学は,反応機構と選択性を理解するための強力なツールです.
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
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