ビアリル結合バイメタリックコバルト触媒を用いたエポキシドのエナチオセレクティブポリメリゼーション:メカニズム研究
Syud M Ahmed1, Albert Poater, M Ian Childers
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States .
Journal of the American Chemical Society
|November 9, 2013
まとめ
ビアリル結合バイメタリックコバルト触媒は,プロピレン酸化物 (PO) のエナチオセレクティブポリメリゼーションを可能にします. 触媒の構造,特にビナフトールリンクナーは,この重要なポリメリゼーションプロセスにおけるステレオ選択性を決定する.
科学分野:
- オーガノメタリック化学
- ポリマー化学 ポリマー化学
- カタリシス カタリシス カタリシス
背景:
- プロピレン酸化物 (PO) のポリメリゼーションは,ポリエーターの生産に不可欠です.
- POポリメリゼーションにおける高エナンチオセレクティビティを達成することは,依然として課題です.
- バイメタリックサランコバルト触媒は,制御されたポリメリゼーションの可能性を秘めています.
研究 の 目的:
- ビアリル結合バイメタリックコバルト (Co) 触媒を用いたプロピレン酸化物 (PO) のエナチオセレクティブポリメリゼーションを調査する.
- 触媒の構造的特徴,選択性,酸化状態,共触媒の役割,およびモノマー連鎖メカニズムを明らかにする.
- 強化された触媒性能のための構造活動関係の探索.
主な方法:
- POポリメリゼーション運動と選択性の実験的調査.
- 異なるリンク器構造を持つ新しい二金属触媒の合成.
- 機械的洞察と構造分析のための密度関数理論 (DFT) 計算.
主要な成果:
- ビナフトールリンクナーの絶対的ステレオ化学は,エナチオセレクティビティの決定に極めて重要です.
- 新しい柔軟なバイフェノルリンクカー触媒は,選択性が低いものの,エナチオセレクティブPOポリメリゼーションを示した.
- DFTは,活性触媒の形態が,エクソアニオンリガンドとエンドポリマーアルコキシドを含むことを明らかにしました.
- イニシエーションは,エンドクロライドリガンドによって好ましい; 伝播は,2つのエクソカルボキシラートリガンドから恩恵を受けます.
結論:
- ビアリル結合バイメタリックコセラン触媒は,エナチオセレクティブPOポリメリゼーションに有効です.
- 触媒の設計,特にリンクナーのステレオ化学と柔軟性,エナチオセレクティビティに大きく影響する.
- DFTからの詳細なメカニズム理解は,より効率的な触媒の設計に役立ちます.
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