Mechanistic investigations of a stable, highly active, extremely sterically shielded molecular gold catalyst

An N-heterocyclic carbene gold complex IPr**AuNTf2 has been synthesized, spectroscopically investigated, structurally characterized, and used as a highly active and stable catalyst in the Hashmi phenol synthesis (IPr**=1,3-di-p-tolylimidazol-2-ylidene with four di-tert-butylbenzhydryl ortho substitu...

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Hauptverfasser: Weber, Simone G. (VerfasserIn) , Zahner, David (VerfasserIn) , Rominger, Frank (VerfasserIn) , Straub, Bernd Franz (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: March 25, 2013
In: ChemCatChem
Year: 2013, Jahrgang: 5, Heft: 8, Pages: 2330-2335
ISSN:1867-3899
DOI:10.1002/cctc.201200944
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1002/cctc.201200944
Verlag, lizenzpflichtig, Volltext: https://onlinelibrary.wiley.com/doi/abs/10.1002/cctc.201200944
Volltext
Verfasserangaben:Simone G. Weber, David Zahner, Frank Rominger, and Bernd F. Straub
Beschreibung
Zusammenfassung:An N-heterocyclic carbene gold complex IPr**AuNTf2 has been synthesized, spectroscopically investigated, structurally characterized, and used as a highly active and stable catalyst in the Hashmi phenol synthesis (IPr**=1,3-di-p-tolylimidazol-2-ylidene with four di-tert-butylbenzhydryl ortho substituents, Tf=trifluoromethansulfonyl). A side reaction comprises an irreversible arene oxide ring opening with subsequent 1,2 methyl shift. The advantage of the steric demand of the ancillary ligand was explained by higher equilibrium concentrations of the cationic gold species, the circumvention of inactive dinuclear intermediates, and the inhibition of catalyst decomposition pathways. The methanol addition-hydration of alkynes featured a turnover-limiting proton transfer step of an alkenylgold catalyst resting state, indicated by a large primary kinetic isotope effect and an alkyne competition experiment.
Beschreibung:Gesehen am 04.10.2021
Beschreibung:Online Resource
ISSN:1867-3899
DOI:10.1002/cctc.201200944