トングステンオクソアルキリデン複合体によって促進されるZ-選択的オレフィン転移反応
Dmitry V Peryshkov1, Richard R Schrock, Michael K Takase
1Department of Chemistry 6-331, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|November 24, 2011
まとめ
新しいボルンガムの触媒は,Z選択オレフィン結合を促進し,高収量とステレオ選択性を達成します. ボロン化合物による活性化により,熱力学的産物形成のための触媒活性が強化されます.
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
- オーガニック・シンセシス オーガニック・シンセシス
背景:
- トングステン-オクソ複合体は,様々な触媒変換において極めて重要です.
- オレフィン結合のための選択的触媒の開発は,有機合成における重要な課題です.
研究 の 目的:
- 新しいボルンガム-オクソ複合体を合成し,特徴づけること.
- Z選択オレフィン結合反応におけるこれらの複合体の触媒活性を評価する.
- 触媒性能に対するルイス酸活性化の効果を調査する.
主な方法:
- リガンド添加反応によるボルンガム-オクソ複合体の合成.
- スペクトロスコーピテクニックを用いた特徴付け (詳細は抽象文に記載されていません).
- 終端オレフィンとのZ選択オレフィン結合における触媒試験.
- トリス (pentafluorophenyl) ボランを用いたルイス酸の活性化.
主要な成果:
- 新しいボルンガム-オクソ複合体,W ((O) ((CH-t-Bu) ((OHMT) ((Me ((2) Pyr)) ((PMe ((2) Ph)) (5) が合成されました.
- 複合体5は,端末オレフィンのZ選択結合の触媒として高い有効性を示し,0.2%の負荷で>75%の製品と>99%のZ構成を生成しました.
- 複合体5をB ((C ((6) F ((5)) ((3)) で活性化すると,熱力学的産物 (~20%Z) を生成する非常に活性な触媒 (5·B ((C ((6) F ((5)) ((3)) が生成される.
結論:
- 合成されたボルンガム-オクソ複合体5は,Z選択オレフィン結合のための非常に効果的な触媒である.
- ルイス酸の活性化により,B (C) (6) F (5)) (3) が触媒の活性と選択性を変化させる.
- この研究は,ステレオ選択的オレフィン変換のための新しい触媒システムを提供しています.
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