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对Heck反应与基酸盐的研究:可以控制1,2-迁移吗? 范围和局限性 范围和局限性
Jean-Philippe Ebran1, Anders L Hansen, Thomas M Gøgsig
1The Center for Insoluble Protein Structures inSPIN, Department of Chemistry, the Interdisciplinary Nanoscience Center, University of Aarhus, Langelandsgade 140, 8000 Aarhus, Denmark.
Journal of the American Chemical Society
|May 4, 2007
概括
这项研究引入了Heck合反应的新催化剂系统,使得从简单的乙烯酸盐和酸盐合成二烯产物. 布赫瓦尔德的双基基酸联体X-Phos有效地促进了乙烯基替代,同时抑制了不必要的中间迁移.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- 赫克合反应是碳-碳键形成的强大工具.
- 开发高效的催化系统来合非激活基板仍然是一个挑战.
- 控制区域选择性和防止1,2-迁移等副作用对于合成实用性至关重要.
研究的目的:
- 开发一种新型的催化剂系统,用于与缺电子基因的非活性乙烯酸盐的Heck合.
- 探索在这种转换中使用布赫瓦尔德的基基酸 (例如,X-Phos) 作为配体.
- 为了研究和控制1,2-迁移的基介质.
主要方法:
- 作为催化剂系统,采用了二复合与环氧八二烯 (PdCl2 ((COD)) 和布克瓦尔德的基双 (X-Phos) 作为催化剂系统.
- 采用化作为添加剂,以促进乙烯基替代.
- 研究了C1替代剂对乙烯酸基底物的影响,以控制异构化和迁移.
- 进行了与化的竞争实验,以评估催化剂的选择性.
主要成果:
- 该X-Phos配体有效地促进了各种基酸盐与缺电子基的Heck合.
- 添加化抑制了基二氧化中介的1,2-迁移.
- 1,2-迁移的程度取决于C1替代物,C1-基四等碳产生最佳结果.
- 通过仔细的连接物选择 (X-Phos vs. P(t-Bu) 实现了与乙烯酸化物在乙烯酸酸盐上的选择性Heck合3).
结论:
- 已经开发出了一种新的高效的催化系统,用于HECK合非活性乙烯酸盐.
- 选择素连接体 (X-Phos或P(t-Bu) 3允许偏好合成迁移或非迁移的Heck产品.
- 催化剂系统证明了对烯化物合的选择性,而不是对乙烯酸C-O键激活的选择性.
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