光学的に活性なアンサ-ジルコノセンのポリメリゼーション触媒を用いたキラルアルファ-オレフィンの運動解像度
Cliff R Baar1, Christopher J Levy, Endy Y-J Min
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, CA 91125, USA.
Journal of the American Chemical Society
|July 1, 2004
まとめ
新しいキラルジルコノセンの触媒は,大型オレフィンの効率的なポリメリゼーションを可能にし,ラセミックモノメアの運動解像度を達成します. この過程でエナチオマーが分離され,高同位性ポリマーと,反応が遅い同位体で濃縮された反応しないモノマーが得られます.
科学分野:
- 有機金属化学 有機金属化学
- ポリマーサイエンスの科学
- カタリシス カタリシス カタリシス
背景:
- キラルアルファ-オレフィンポリメリゼーションのためのエナティオプアC1対称メタロセンの開発.
- 新型ジルコノセーン二塩化物の合成,サイクロペンタディエニルリガンドの特定のエナチオピュール置換剤.
研究 の 目的:
- キラルアルファ-オレフィンのポリメリゼーションのためのエナンチオピュアメタロセンの合成と評価.
- これらのメタロセンの触媒的活動と選択性を,大型ラセミックモノメアのポリメリゼーションで調査する.
- これらのシングルサイト触媒を使用して,ラセミックモノメアの運動解像度の可能性を調査する.
主な方法:
- エナンチオピュールC1対称ジルコノセーン二塩化物の合成.
- メチルアルミノキサン (MAO) によるメタロセンの活性化.
- 大量のラセミックアルファ-オレフィンのポリマー化.
- 運動解像度分析 (選択性因子"s"の決定)
- (13) ポリマー戦術性分析のためのC NMRスペクトロスコーピー.
- 構造的およびステリック分析のためのX線結晶学および分子力学.
主要な成果:
- メタロセンは,大量のラセミックモノマーをポリメリ化する前例のない活性を示した.
- 3,4-ジメチル-1-ペンテンの場合,s > 15までの分離因子で,ラセミックモノマーの効果的な動的解像度が達成されました.
- 産生されたポリマー,例えばポリー・3・メチル・1・ペンテンは,高い同毒性を示した.
- 構造的および計算的分析により,移行状態におけるステリック相互作用の洞察が得られた.
結論:
- エナティオピュアメタロセンは,キラルアルファ-オレフィンポリメリゼーションの高度に活性で選択的な触媒である.
- これらの触媒は,ラセミックモノメアの効率的な動的分解を可能にし,エナティオメールを分離します.
- 開発された触媒は,高同位性ポリマーとエナチオメリックに濃縮されたモノマーへの経路を提供します.
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