Strong Electron-Donating Ligands Accelerate the Protodeauration Step in Gold(I)-Catalyzed Reactions: A Quantitative Understanding of the Ligand Effect
Strong Electron-Donating Ligands Accelerate the Protodeauration Step in Gold(I)-Catalyzed Reactions: A Quantitative Understanding of the Ligand Effect
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DOI：
10.1021/acs.organomet.6b00346
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发表时间：
2016-07-11
期刊：
影响因子：
2.8
通讯作者：
Belanzoni, Paola
中科院分区：
文献类型：
--
作者：
Gaggioli, Carlo Alberto;Ciancaleoni, Gianluca;Belanzoni, Paola
我们对模型金（I）环化反应的脱气步骤中的配体电子效应进行了理论探讨，并得到了实验数据。通过密度泛函理论（DFT）的方法研究的protodeauration的机制，并通过电荷位移函数（CDF）的配体的给电子能力进行量化。我们发现，在文献中经常遇到的假设，“强电子供体配体加速protodeauration”可以设置到一个定量的框架，我们结合DFT/CDF理论方法，这使我们也可以合理化的Buchwald膦型配体在这个过程中的最高催化效率。分析了配体对金配合物基底（LAu-S）键强度的影响，发现LAu-S相互作用能与活化能呈线性关系。最后，能量分解分析（EDA）是用来调查的LAu-S键，我们表明，在相互作用能的变化主要是由于静电分量的变化，其值反过来调制的配体给电子功率。
We have conducted a theoretical exploration of the ligand electronic effect in the protodeauration step of a model gold(I) cyclization reaction, for which experimental data are available. The mechanism of the protodeauration is investigated through a density functional theory (DFT) approach, and the electron-donating power of the ligand is quantified through the charge displacement function (CDF). We find that the frequently encountered assumption in the literature that "strong electron donating ligands accelerate the protodeauration" can be set into a quantitative framework by our combined DFT/CDF theoretical approach, which allows us also to rationalize the highest catalytic efficiency of Buchwald phosphine type ligands in this process. We analyze the ligand effect on the gold complex substrate (LAu-S) bond strength, namely the bond to be broken during the protodeauration, and we find that the LAu-S interaction energies linearly correlate with the activation barriers. Finally, energy decomposition analysis (EDA) is used to investigate the LAu-S bond, and we show that changes in the interaction energies are mainly due to changes in the electrostatic component, whose value is in turn modulated by the ligand electron-donating power.