アリルC-H結合のアイリジウムへの選択的添加は,オーソを調整グループに配合する. ケラートアシストされていない
Xiawei Zhang1, Mira Kanzelberger, Thomas J Emge
1Department of Chemistry, Rutgers-The State University of New Jersey, Piscataway, New Jersey 08854, USA.
Journal of the American Chemical Society
|October 14, 2004
まとめ
ピンサー結合イリジウム複合体は,ニトロベンゼンとアセトフェノンと反応し,アリルC-H結合添加を経由してO,C-ケラ化製品を形成する. この反応は,初期機能群の調整なしに発生し,C-H活性化メカニズムに関する以前の仮定に異議を唱える.
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
- 合成化学 合成化学とは
背景:
- (PCP) Irとして表記されるピンサー・リガートイリジウム複合体は,触媒として知られています.
- アリルC-H結合の活性化は,有機合成における重要な変換である.
研究 の 目的:
- (PCP) Irのニトロベンゼンおよびアセトフェノンとの反応機構を調査する.
- C-H機能化プロセスに含まれる地域選択性と中間物質の解明.
主な方法:
- 環境温度での (PCP) Ir前駆体とニトロベンゼンおよびアセトフェノンの反応.
- 形成されたO,Cケラド複合体の構造的特徴.
- 低温核磁気共鳴 (NMR) 研究で,反応中間物質と運動を検出する.
主要な成果:
- アリルC-H結合添加と酸素協調によるO,C-ケラート複合体の形成.
- 反応は,C−H添加が続く初期機能群調整を経由して進行しないことを実証する.
- 運動学的研究により,低温でのパラおよびメタC-H機能化が好ましいことが明らかになり,その後,オルソ添加は補助なしで発生しました.
結論:
- これらの反応におけるC-H添加は,最初の酸素調整によって導かれることはありません.
- 非補助的なオーソC-H加法メカニズムが提案され,その後にケレーションが行われます.
- この研究は,ピンチャー結合イリジウム複合体によるC-H活性化のメカニズム的経路に関する新しい洞察を提供します.
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