Mechanism of Alkyne Hydroarylation Catalyzed by (P,C)-Cyclometalated Au(III) Complexes - Université de Pau et des Pays de l'Adour Accéder directement au contenu
Article Dans Une Revue Journal of the American Chemical Society Année : 2022

Mechanism of Alkyne Hydroarylation Catalyzed by (P,C)-Cyclometalated Au(III) Complexes

Marte Sofie Martinsen Holmsen
Charlie Blons
  • Fonction : Auteur
Abderrahmane Amgoune
Matthieu Regnacq
  • Fonction : Auteur
Denis Lesage
  • Fonction : Auteur
E. Daiann Sosa Carrizo
Pierre Lavedan

Résumé

Over the last 5-10 years, gold(III) catalysis has developed rapidly. It often shows complementary if not unique features compared to gold(I) catalysis. While recent work has enabled major synthetic progress in terms of scope and efficiency, very little is yet known about the mechanism of Au(III)-catalyzed transformations and the relevant key intermediates have rarely been authenticated. Here, we report a detailed experimental/computational mechanistic study of the recently reported intermolecular hydroarylation of alkynes catalyzed by (P,C)-cyclometalated Au(III) complexes. The cationic (P,C)Au(OAcF)+ complex (OAcF = OCOCF3) was authenticated by mass spectrometry (MS) in the gas phase and multi-nuclear NMR spectroscopy in solution at low temperatures. According to density functional theory (DFT) calculations, the OAcF moiety is κ2-coordinated to gold in the ground state, but the corresponding κ1-forms featuring a vacant coordination site sit only slightly higher in energy. Side-on coordination of the alkyne to Au(III) then promotes nucleophilic addition of the arene. The energy profiles for the reaction between trimethoxybenzene (TMB) and diphenylacetylene (DPA) were computed by DFT. The activation barrier is significantly lower for the outer-sphere pathway than for the alternative inner-sphere mechanism involving C-H activation of the arene followed by migratory insertion. The complex of DPA was characterized by MS. An unprecedented σ-arene Au(III) complex with TMB was also authenticated both in the gas phase and in solution. The cationic complexes [(P,C)Au(OAcF)]+ and [(P,C)Au(OAcF)(σ-TMB)]+ stand as active species and off-cycle resting state during catalysis, respectively. This study provides a rational basis for the further development of Au(III) catalysis based on activation
Fichier principal
Vignette du fichier
Hal_(PC)Au(III)-catalyzed hydroarylation_OK.pdf (1.89 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Licence : CC BY - Paternité

Dates et versions

hal-03906104 , version 1 (27-07-2023)

Identifiants

Citer

Marte Sofie Martinsen Holmsen, Charlie Blons, Abderrahmane Amgoune, Matthieu Regnacq, Denis Lesage, et al.. Mechanism of Alkyne Hydroarylation Catalyzed by (P,C)-Cyclometalated Au(III) Complexes. Journal of the American Chemical Society, 2022, 144 (49), pp.22722-22733. ⟨10.1021/jacs.2c10737⟩. ⟨hal-03906104⟩
71 Consultations
28 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More