チイラニウムとセレナニウムイオンからアルケーンへの直接の硫およびセレナニウムグループ移転の観察
Scott E Denmark1, William R Collins, Matthew D Cullen
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA. sdenmark@illinois.edu
Journal of the American Chemical Society
|February 21, 2009
まとめ
スルフェニウムとセレニウムイオンは,三つ組の環からアルケーンにステレオ特異的に移動する. セレニウム移転は瞬間的であったが,硫黄移転は様々であり,硫黄とセレニウムイオンの安定性が異なることを示した.
科学分野:
- オルガノ硫黄化学 オルガノ硫黄化学
- オルガノセレニウム 化学 オルガノセレニウム化学
- 反応メカニズム 反応メカニズム
背景:
- スルフェニウムとセルフェニウムイオンは,反応性のある中間物質である.
- -イラニウムイオンとして知られる3つ構成のリング種は,前駆体である.
- それらの転送反応を理解することは,合成アプリケーションの鍵です.
研究 の 目的:
- スルフェニウムとセレネニウムイオンのステレオ特異的移転を調査する.
- チラニウムとセレニウムイオンの反応性と安定性を比較する.
- 移転能力とイオン安定性に対する置換剤の影響を調査する.
主な方法:
- シルバーヘクサフッロアンチモナートを使用したチラニウムおよびセレニルイラニウムヘクサフッロアンチモナートの生成.
- NMRスペクトル (1H, 13C, 77Se) を使用して生成されたイオンの特徴づけ.
- 異なった温度で活性化されていないアルケンのイオン転送反応の研究.
- セレニラニウムイオンの相対的な安定性を決定するための均衡測定.
主要な成果:
- チイラニウムイオンは,変数移転能力を示した;S-フェニルチイラニウムはゆっくり移転したが,S-メチルチイラニウムは移転しなかった.
- セレニニウムイオン (Se-フェニルおよびSe-ブチル) は,低温 (-70 °C) でセレニニウム分子を瞬時に転送した.
- 1-フェニルセレニウムイオンの相対的な安定性の順序は,シス-テトラメチレン <トランス-2,3-ディプロピル ≈トランス-2,3-ディイソプロピル <シス-ヘクサメチレン.
結論:
- スルフェニウムとセレネニウムイオンは,異なった移転行動と安定性を表しています.
- セレニウムイオンは一般的に,セレニウムイオンよりも反応性が高く,セレニウム分子を簡単に転送します.
- この研究は,これらの重要な硫黄とセレニウム中間物質の安定性と反応性を支配する要因についての洞察を提供します.
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