水素原子源として水を使用したアルコールの脱酸素化
David A Spiegel1, Kenneth B Wiberg, Laura N Schacherer
1Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
Journal of the American Chemical Society
|September 8, 2005
まとめ
トリアルキルボランは水素源として水を用いてメチルキサンタートの還元性去酸素化を促進する. この新しい反応により,高効率のアルカンとデウテリウムが組み込まれ,水とボランに対する新しい反応性を明らかにします.
科学分野:
- 有機金属化学 有機金属化学
- ラジカル・ケミストリー (Radical Chemistry) とは
- オーガニック・シンセシス オーガニック・シンセシス
背景:
- メチルキサンタートは,有機合成における多用途の前駆体である.
- 還元性脱酸素化は,機能的グループ操作の重要な変換である.
- 水とトライキルボランは,既知の反応パターンを持つ一般的な反応剤です.
研究 の 目的:
- トライアルキルボランを用いたO-アルキル-S-メチルディチオカルボナートの還元性去酸素化を調査する.
- 水素/デウテリウム源として水またはデウテリウム酸化物の使用を調査する.
- 水とトライアルキルボランの反応機構と新種の反応性を解明する.
主な方法:
- 反応はトライアルキルボラン (トリメチルボラン,トリエチルボラン,トリビチルボラン) とO-アルキル-S-メチルディチオカルボネートを用いて行われました.
- 水または二酸化デュテリウムは,それぞれプロチウムまたは二酸化デュテリウムの源として使用されました.
- トライアルキルボラン-水複合体と反応機構を研究するために,Ab initio計算を行った.
主要な成果:
- 還元性脱酸素化は,プロチオアルカンまたはデュテリオアルカン産物の高収量で進行した.
- デウテリウム酸化物を使用すると,優れたデウテリウム組み込みレベルが達成されました.
- Ab initio計算では,トライキルボラン-水複合体のO-H結合解離エネルギーが低いことが示され,ラジカルチェーンメカニズムをサポートしています.
結論:
- トリアルキルボランは,水を用いたメチルキサンタートの新種の還元性去酸素化を媒介する.
- この方法は,高収量と同位体ラベリングを持つアルカンへの多用途の経路を提供します.
- この発見は,水とトライキルボランに対して,これまで認識されなかった反応モードを明らかにした.
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