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影响因子：7.5
DOI码：10.1039/c7sc02964k
发表刊物：CHEMICAL SCIENCE
摘要：Mechanistic studies of the catalyst [Pd2(dba)3/1,1′-bis(tert-butyl(pyridin-2-yl)phosphanyl)ferrocene, L2] for olefin alkoxycarbonylation reactions are described. X-ray crystallography reveals the coordination of the pyridyl nitrogen atom in L2 to the palladium center of the catalytic intermediates. DFT calculations on the elementary steps of the industrially relevant carbonylation of ethylene (the Lucite α-process) indicate that the protonated pyridyl moiety is formed immediately, which facilitates the formation of the active palladium hydride complex. The insertion of ethylene and CO into this intermediate leads to the corresponding palladium acyl species, which is kinetically reversible. Notably, this key species is stabilized by the hemilabile coordination of the pyridyl nitrogen atom in L2. The rate-determining alcoholysis of the acyl palladium complex is substantially facilitated by metal–ligand cooperation. Specifically, the deprotonation of the alcohol by the built-in base of the ligand allows a facile intramolecular nucleophilic attack on the acyl palladium species concertedly. Kinetic measurements support this mechanistic proposal and show that the rate of the carbonylation step is zero-order dependent on ethylene and CO. Comparing CH3OD and CH3OH as nucleophiles suggests the involvement of (de)protonation in the rate-determining step.
合写作者：Zhihong Wei；Jie Liu；Ricarda Dühren；Anke Spannenberg；Haijun Jiao；Helfried Neumann；Ralf Jackstell；Robert Franke；Matthias Beller*；
第一作者：Kaiwu Dong；Rui Sang
论文类型：期刊论文
通讯作者：Matthias Beller*；
文献类型：期刊
卷号：9
期号：9
页面范围：2510-2516
是否译文：否
发表时间：2018-03-07
收录刊物：SCI
发布期刊链接：https://pubs.rsc.org/en/content/articlelanding/2018/sc/c7sc02964k