イリジウム触媒によるアリル置換における地域選択性の起源
Sherzod T Madrahimov1, Qian Li2, Ankit Sharma2
1Department of Chemistry, University of Illinois , 600 South Mathews, Urbana, Illinois 61801, United States.
Journal of the American Chemical Society
|October 27, 2015
まとめ
トリフェニルフォスフィートリガンドを含むイリジウム触媒は,枝分かれした製品に対して高い地域選択性を示す. ステリックではなく非共性相互作用が,触媒反応におけるこの選択性を説明する.
科学分野:
- 有機金属化学
- カタリシス
- 有機合成
背景:
- カタリシスの地域選択性は,特定の有機製品を合成するために不可欠です.
- トリフェニルフォスフィート (P(OPh) 3を含むイリジウム複合体は,高い地域選択性があることが知られている.
- この選択性の起源を理解することは,触媒設計の鍵です.
研究 の 目的:
- 枝分かれした製品を好むイリジウム触媒反応における地域選択性の起源を調査する.
- 活性な触媒物種と主要な中間物質を特定する.
- イリジウム対パラジウムシステムの選択性を支配する要因を解明する.
主な方法:
- イリジウム複合体とトリフェニルフォスフィートリガンドの詳細な研究
- アリリジウム複合体の生成と特徴付け
- 電子と非共性相互作用を評価するための計算研究.
- アリルパラジウム複合体との比較
主要な成果:
- 活性触媒は,P,C結合種を静止状態としてP,OPh) 3のサイクルメタレーションによって形成される.
- アリリジウム複合体は有能な中間物質である.
- 電荷と結合長などの要因は,イリジウムとパラジウムとの選択性を区別しない.
- 計算上の研究は,弱い,魅力的な非共性相互作用が,イリジウムとの分岐産物形成を好むことを示している.
結論:
- ビニルC-H結合とのH結合受容体相互作用など,弱引力非共性相互作用は,イリジウム触媒の地域選択性にとって重要である.
- これらの吸引力は,排斥的なステリック効果とともに,触媒的選択性を合理化するために不可欠である.
- 発見は,触媒開発における非共性相互作用の検討の重要性を強調する.
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