ルイス酸が促進したチタンアルキリデンの形成:オレフィントリメリゼーション触媒に関連するオフサイクル中間物質
Aaron Sattler1, David G VanderVelde, Jay A Labinger
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology , Pasadena, California 91125, United States.
Journal of the American Chemical Society
|July 10, 2014
まとめ
エチレンとα-オレフィンのトリメリゼーションのために2つの新しいフェノキシイミンチタニウム前触媒が合成されました. 1つの前触媒は効率的に1-ヘクセンとC15オレフィンを生成し,もう1つは複雑な反応性を示すが,それでもオレフィントリメリゼーションを可能にします.
科学分野:
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
- ポリマーサイエンスの科学
背景:
- エチレンとα-オレフィンのトリメリゼーションは,貴重な化学物質の生産に不可欠な反応です.
- 効率的で選択的な前触媒の開発は,オレフィン変換技術の進歩の鍵です.
- タイタンベースの複合体は,触媒的なオレフィンオリゴメリゼーションの有望な経路を提供します.
研究 の 目的:
- 新型フェノキシイミンチタニウム前触媒の合成と特徴づけ.
- エチレンおよびα-オレフィントリメリゼーションにおけるこれらの前触媒の触媒活性を調べる.
- オフサイクル反応を含む活性化メカニズムと反応経路の解明.
主な方法:
- X線 difraksionを用いたチタニウム前触媒の合成と構造的特徴付け.
- 前触媒の活性化には,トリス・ペンタフローロフェニル・ボラン (B・C6F5) 3) が用いられる.
- 低温での反応中間物質とメカニズムをモニタリングするための光譜分析 (NMR).
- エチレンと1-ペンテンのトリメリゼーションにおける触媒性能の評価.
主要な成果:
- (FI) Ti (CH2SiMe3) 2Meと (FI) Ti (CH2CMe3) 2Meという2つの新しいフェノキシイミンチタニウム前触媒が成功して合成され,特徴づけられました.
- (FI) Ti (CH2SiMe3) 2MeをB (C6F5) 3で活性化すると,エチレンを効率的に1 - ヘクセンと1 - ペンテンからC15オレフィンにトリメリザーします.
- ネオペンチルアナログである (FI) Ti ((CH2CMe3) 2Meは,α除去と分子内転移を含む複雑な低温反応性を示すが,オレフィントリメリゼーションの効果的な前触媒である.
結論:
- 合成されたフェノキシイミンチタニウム複合体は,エチレンとα-オレフィントリメリゼーションの有効な前触媒である.
- この研究は,リガンド置換剤によって異なる活性化経路と中間種を明らかにした.
- オフサイクル経路にもかかわらず,ネオペンチル前触媒は強力な触媒活性を示し,これらのシステムの汎用性を強調しています.
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