TY - JOUR
T1 - Strong Electron-Donating Ligands Accelerate the Protodeauration Step in Gold(I)-Catalyzed Reactions
T2 - A Quantitative Understanding of the Ligand Effect
AU - Gaggioli, Carlo Alberto
AU - Ciancaleoni, Gianluca
AU - Zuccaccia, Daniele
AU - Bistoni, Giovanni
AU - Belpassi, Leonardo
AU - Tarantelli, Francesco
AU - Belanzoni, Paola
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/7/11
Y1 - 2016/7/11
N2 - 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.
AB - 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.
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U2 - 10.1021/acs.organomet.6b00346
DO - 10.1021/acs.organomet.6b00346
M3 - Article
AN - SCOPUS:84978796223
SN - 0276-7333
VL - 35
SP - 2275
EP - 2285
JO - Organometallics
JF - Organometallics
IS - 13
ER -