Arylic C–X Bond Activation by Palladium Catalysts: Activation Strain Analyses of Reactivity Trends

Abstract We have quantum chemically explored arylic carbon–substituent bond activation via oxidative insertion of a palladium catalyst in C6H5X + PdLn model systems (X = H, Cl, CH3; Ln = no ligand, PH3, (PH3)2, PH2C2H4PH2) using relativistic density functional theory at ZORA-BLYP/TZ2P. Besides explo...

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Autores principales: Pascal Vermeeren, Xiaobo Sun, F. Matthias Bickelhaupt
Formato: article
Lenguaje:EN
Publicado: Nature Portfolio 2018
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Acceso en línea:https://doaj.org/article/ceabaa0dbacf4233933abfd0fa8fabda
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Sumario:Abstract We have quantum chemically explored arylic carbon–substituent bond activation via oxidative insertion of a palladium catalyst in C6H5X + PdLn model systems (X = H, Cl, CH3; Ln = no ligand, PH3, (PH3)2, PH2C2H4PH2) using relativistic density functional theory at ZORA-BLYP/TZ2P. Besides exploring reactivity trends and comparing them to aliphatic C–X activation, we aim at uncovering the physical factors behind the activity and selectivity. Our results show that barriers for arylic C–X activation are lower than those for the corresponding aliphatic C–X bonds. However, trends along bonds or upon variation of ligands are similar. Thus, bond activation barriers increase along C–Cl < C–H < C–C and along Pd < Pd(PH3) or Pd(PH2C2H4PH2) < Pd(PH3)2. Activation strain analyses in conjunction with quantitative molecular orbital theory trace these trends to the rigidity and bonding capability of the various C–X bonds, model catalysts, and ligands.