アリルハリドによって電子が豊富なオレフィンのヒックアリレーションは,イオン液が促進し,高度に地域選択性がある
Jun Mo1, Lijin Xu, Jianliang Xiao
1Department of Chemistry, Liverpool Centre for Materials and Catalysis, University of Liverpool, Liverpool L69 7ZD, UK.
Journal of the American Chemical Society
|January 13, 2005
まとめ
イオン性液を用いたパラジウム触媒によるヘックアリレーションは,枝分かれしたアリラートオレフィンの効率的な合成を可能にします. この方法は,多様なアリルハリドで高い地域選択性を提供し,従来の分子溶媒の性能を上回ります.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- グリーン・ケミストリー (Green Chemistry)
背景:
- ヘック反応は,重要な炭素-炭素結合形成反応である.
- 伝統的なヘック反応は,しばしば高価で利用できないアリルトリフラートに依存する.
- 電子が豊富なオレフィンによるヘック反応において高い地域選択性を達成することは困難である.
研究 の 目的:
- 容易に入手可能なアリルブロミドとヨドドを使用した地域選択のパラジウム触媒ヘックアリレーション法を開発する.
- イミダゾリウムイオン液体をヘックアリレーションの反応媒体として使用することを調査する.
- 多様な置換剤を用いた,枝分かれした,アリラートオレフィンの合成を調査する.
主な方法:
- パラジアム触媒によるビニルエーテル,エナミド,アリルトリメチルシランのヘックアリレーション.
- イミダゾリウムイオン液体を反応媒体として利用する.
- カップリングパートナーとして様々なアリルブロミドとヨジドを使用しています.
主要な成果:
- イミダゾリウムイオン液体では,高効率と顕著な地域選択性が達成されました.
- この反応で得られたのは,枝分かれしたアリラートオレフィンのみで,アルファがヘテロ原子に (ビニルエーテルとエナミドの場合) またはベータがヘテロ原子に (アリルトリメチルシランの場合) アリル置換された.
- 対照的に,分子溶媒での反応は,地域異性体の混合物を生成した.
結論:
- イミダゾリウムイオン液体は,パラジウム触媒によるヘックアリレーションにおけるユニークな地域制御を促進します.
- この方法は,枝分かれした,アライラドオレフィンを合成するためのシンプルで効果的な,よりグリーンな代替手段を提供します.
- 開発された化学は,ヘック反応の範囲を拡大し,より幅広い基質とアリレーティング剤を含むようにします.
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