超臨界の二酸化炭素中の1,n端のダイオルの選択的単一保護:溶媒調節可能な脱対化の顕著な例
Peter Licence1, William K Gray, Maia Sokolova
1School of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
Journal of the American Chemical Society
|January 6, 2005
まとめ
ディオールとアルコールを用いた超臨界CO2反応は,モノエーテルまたはビスエーテル製品に好意的に調整することができます. 圧力による反応混合物の変化による選択性シフト.
科学分野:
- 化学工学は化学工学というものです.
- 有機化学 オーガニック・ケミストリー
- グリーン・ケミストリー 緑の化学
背景:
- 超臨界流体は,ユニークな反応環境を提供します.
- 選択的なエーテル合成は,様々な化学応用において極めて重要です.
- 反応における製品の分布を制御することは,重要な課題です.
研究 の 目的:
- ディオールとアルコールからモノエーテルとバイエーテルの合成を調査する.
- 超臨界CO2条件が反応選択性に及ぼす影響を調査する.
- 製品配布を決定する段階的行動の役割を理解する.
主な方法:
- 反応は1,n端二酸化物 (n=3,6) と単純なアルコール (MeOH,EtOH,n-PrOH) を用いて実施した.
- 超臨界二酸化炭素 (scCO2) を反応媒介として使用し,アンバーライスト15を酸性触媒として使用した.
- 選択性の変化を研究するために,反応温度 (150°C) と圧力 (50-200 bar) を体系的に変化させました.
主要な成果:
- モノエーテル製品とビスエーテル製品の選択性は,反応圧を変化させることで成功的に切り替えられました.
- 150°Cと50barで,反応はビスエーテル形成を好んだ (1:20比).
- 150°Cと200 barで,反応は非対称化モノエーテル形成 (9:1比) を好みました.
- 観察された選択性スイッチは,反応混合物の相状態 (単相対二相) と相関していた.
結論:
- 超臨界CO2における反応相行動は,エーテル合成の選択性を制御する重要な要因である.
- モノフェーシック条件はモノエーテル形成を好み,バイフェーシック条件はビスエーテル形成を好む.
- 本研究は,scCO2を用いたエーテル化反応における選択性を調節するための方法を提供する.
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