Investigations into the Stability of Tethered Palladium(II) Pincer Complexes during Heck Catalysis
Investigations into the Stability of Tethered Palladium(II) Pincer Complexes during Heck Catalysis
复制标题
Heck 催化过程中束缚钯 (II) 钳配合物稳定性的研究
DOI：
10.1021/om048992v
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发表时间：
2005
期刊：
影响因子：
2.8
通讯作者：
M. Weck
中科院分区：
文献类型：
--
作者：
W. Sommer;Kunquan Yu;J. Sears;Yaying Ji;Xiaolai Zheng;R. Davis;C. Sherrill;†‡ and Christopher W. Jones;M. Weck
各种苍白的PCP钳形络合物通过酰胺或醚键共价连接到聚合物和二氧化硅载体上，并在碘苯和丙烯酸丁酯的Heck反应中进行了评估。通过中毒和动力学研究，确定了所研究的所有络合物在反应条件下的分解。此外，提出了PCP和SCS钳形Pd(II)络合物分解途径的初始步骤，并用原位核磁共振、质谱学、X-射线吸收光谱和计算方法进行了验证。这些发现和我们以前的报道有力地表明，所有的Pd(II)钳形配合物在Heck反应中只是简单的前催化剂，分解形成具有催化活性的Pd(0)物种。
A variety of palladated PCP pincer complexes are covalently tethered onto polymeric and silica supports via either amide or ether linkages and are evaluated in the Heck reaction of iodobenzene and n-butyl acrylate. The decomposition under reaction conditions of all complexes studied is established through poisoning and kinetic studies. Furthermore, the initial steps of the decomposition pathway of PCP as well as SCS pincer Pd(II) complexes are proposed and validated using in situ NMR, mass spectroscopy, and XAS as well as computational methods. These findings together with our previous reports strongly suggest that all Pd(II) pincer complexes are simply precatalysts during the Heck reaction that decompose to form catalytically active Pd(0) species.