从有机中消除β-的机制研究 (II) 酸复合物
Erik J Alexanian1, John F Hartwig
1Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|October 29, 2008
概括
这项研究研究了(II) 乙烯酸复合物,揭示了β-的消除是它们热分解的关键,形成甲和乙. 反应速率受到氨酸度和酸盐替代物的影响.
科学领域:
- 有机金属化学 有机金属化学
- 反应机制 反应机制
- 金催化剂的使用方法
背景情况:
- 双氨基 ((II) 乙烯酸复合物是有机金属反应中的关键中间体.
- 了解它们的热分解途径对于设计新的催化过程至关重要.
研究的目的:
- 阐明在双氨基 ( bisphosphine alkylplatinum) 酸盐复合物中的热反应的详细机械路径.
- 为了比较乙酸和酸复合物的β-消除的机制和动力学.
主要方法:
- 热反应的详细机械研究.
- 动力学研究以确定反应速率的依赖性.
- 动态同位素效应测量以确定速度限制步骤.
- 对替代酸盐复合物的研究,以评估固体和电子效应.
主要成果:
- 热反应产生甲和埃诺,产品的分布取决于埃诺固体.
- 反应速率与添加的氨酸度相反,表明氨酸解离会先于β-消除.
- 一个主要的动态同位素效应支持限制速率的β-消除或C-H键形成.
- 取电子替代剂对酸盐阻滞反应的影响很小,而β-基替代剂对速率的影响很小.
- 酸复合物的分解速度与类似的基复合物相似,在发生差异时,酸β-的消除速度更快.
结论:
- 消除β-是 ((II) 酸盐复合物的热分解的一个关键步骤.
- 该机制涉及可逆的氨酸解离,其次是β-消除.
- 酸联体体的立体和电子因素影响反应速率,尽管整体分解速率与基复合物相似.
相关概念视频
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