クロミウムの構造と反応性
Pengcheng Wu1, Glenn P A Yap1, Klaus H Theopold1
1Department of Chemistry and Biochemistry and Center for Catalytic Science and Technology , University of Delaware , Newark , Delaware 19716 , United States.
Journal of the American Chemical Society
|June 1, 2018
まとめ
クロミウム ((VI) ダイアルキルはβ-水素が欠け,安定したアルキリデン複合体を形成する. これらの反応性中間物質はC-H結合を活性化し,オレフィンと反応し,金属サイクロブタンを形成する.
科学分野:
- 有機金属化学
- 無機化学
- カタリシス
背景:
- Bis ((arylimido) Cr ((VI) ダイアキルは,反応性中間物の前駆体である.
- オーガノクロム化合物の分解経路は重要な関心事である.
- アルキリデン複合体は,様々な触媒変換において重要な役割を果たします.
研究 の 目的:
- β-水素欠乏したbis ((arylimido) Cr ((VI)) ダイアキルの分解機構を調査する.
- 新しいアルキリデン複合体を合成し,特徴づけること.
- これらのアルキリデンの中間物質の反応性を調べるため
主な方法:
- ビス ((arylimido) Cr ((VI) ダイアキルの合成
- α-水素抽出を含む分解研究
- トリフェニルフォスフィンで中間物質を捕まえる
- X線結晶学を用いたアルキリデン複合体の構造的特徴化.
- C-H活性化とオレフィンとの反応を含む反応性研究.
主要な成果:
- 分解はα-水素抽出により発生し, (ArN) 2CrCHR ((PPh3) 型の分離可能なアルキリデン複合体 (R = tBu, SiMe3) を生成する.
- このような2つの複合体は構造的に特徴付けられ,協調的に不飽和アルキリデンの中間物質を明らかにした.
- これらの中間物質は高反応性を示し,飽和炭化水素のC−H活性化を可能にしました.
- オレフィンとの反応により,金属サイクロブタンが形成された.
結論:
- β-水素を欠くbis ((arylimido) Cr ((VI)) ダイアキルは,安定したアルキリデン複合体への有効な経路を提供する.
- 特徴づけられたアルキリデン複合体は,C-H活性化とオレフィンサイクル化が可能な非常に反応性の高い中間物質である.
- この研究は,オーガノクロミウム化学と合成におけるアルキリデン複合体の有用性に関する理解を拡大する.
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