Formation of XPhos‐Ligated Palladium(0) Complexes and Reactivity in Oxidative Additions - Archive ouverte HAL
Article Dans Une Revue Chemistry - A European Journal Année : 2019

Formation of XPhos‐Ligated Palladium(0) Complexes and Reactivity in Oxidative Additions

Simon Wagschal
Luca Alessandro Perego
Alexandre Simon
  • Fonction : Auteur
Aida Franco-Espejo
  • Fonction : Auteur
Chanelle Tocqueville
  • Fonction : Auteur
Jennifer Albaneze-Walker
  • Fonction : Auteur
Anny Jutand
  • Fonction : Auteur
Laurence Grimaud

Résumé

Understanding the nature of the intermediate species operating within a palladium catalytic cycle is crucial for developing efficient cross-coupling reactions. Even though the XPhos/Pd(OAc)2 catalytic system has found numerous applications, the nature of the active catalytic species remains elusive. A Pd0 complex ligated to XPhos has been detected and characterized in situ for the first time using cyclic voltammetry and NMR techniques. In the presence of XPhos, Pd(OAc)2 initially associates with the ligand to form a complex in solution, which has been characterized as PdII (OAc)2 (XPhos). This PdII center is then reduced to the Pd0 (XPhos)2 species by an intramolecular process. This study also sheds light on the formation of PdI -PdI dimers. Finally, a kinetic study probes a dissociative mechanism for the oxidative addition with aryl halides involving Pd0 (XPhos) as the reactive species in equilibrium with the unreactive Pd0 (XPhos)2 . Remarkably, the reportedly poorly reactive PhCl reacts at room temperature in the oxidative addition, which confirms the crucial role of the XPhos ligand in the activation of aryl chlorides.

Domaines

Chimie
Fichier non déposé

Dates et versions

hal-03975150 , version 1 (06-02-2023)

Identifiants

Citer

Simon Wagschal, Luca Alessandro Perego, Alexandre Simon, Aida Franco-Espejo, Chanelle Tocqueville, et al.. Formation of XPhos‐Ligated Palladium(0) Complexes and Reactivity in Oxidative Additions. Chemistry - A European Journal, 2019, 25 (28), pp.6980-6987. ⟨10.1002/chem.201900451⟩. ⟨hal-03975150⟩
19 Consultations
0 Téléchargements

Altmetric

Partager

More