π Activation of Alkynes in Homogeneous and Heterogeneous Gold Catalysis

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• 作者：Giovanni Bistoni ; Paola Belanzoni ; Leonardo Belpassi ; Francesco Tarantelli
• 刊名：Journal of Physical Chemistry A
• 出版年：2016
• 出版时间：July 14, 2016
• 年：2016
• 卷：120
• 期：27
• 页码：5239-5247
• 全文大小：439K
• 年卷期：0
• ISSN：1520-5215

文摘

The activation of alkynes toward nucleophilic attack upon coordination to gold-based catalysts (neutral and positively charged gold clusters and gold complexes commonly used in homogeneous catalysis) is investigated to elucidate the role of the σ donation and π back-donation components of the Au–C bond (where we consider ethyne as prototype substrate). Charge displacement (CD) analysis is used to obtain a well-defined measure of σ donation and π back-donation and to find out how the corresponding charge flows affect the electron density at the electrophilic carbon undergoing the nucleophilic attack. This information is used to rationalize the activity of a series of catalysts in the nucleophilic attack step of a model hydroamination reaction. For the first time, the components of the Dewar–Chatt–Duncanson model, donation and back-donation, are put in quantitative correlation with the kinetic parameters of a chemical reaction.