Details

Autor(en) / Beteiligte

• García-Fernández, Pedro D
• Iglesias-Sigüenza, Javier
• Rivero-Jerez, Paula S
• Díez, Elena
• Gómez-Bengoa, Enrique
• Fernández, Rosario
• Lassaletta, José M

Titel

Au I -Catalyzed Hydroalkynylation of Haloalkynes

Ist Teil von

• Journal of the American Chemical Society, 2020-09, Vol.142 (37), p.16082-16089

Ort / Verlag

United States

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The Au -catalyzed reaction between terminal alkynes and aromatic haloalkynes proceeds through divergent pathways depending on the nature of the catalyst counteranion. Thus, cationic complexes containing strongly basic NHC ligands and noncoordinating anions such as BAr catalyze the cis haloalkynylation of the terminal alkyne, whereas introduction of a weakly basic triflate counteranion results in the stereoselective hydroalkynylation of the haloalkyne, yielding haloenyne products in good yields and complete trans selectivity. Experimental and computational studies suggest that the hydroalkynylation reaction takes place via nucleophilic attack of the terminal alkyne to the C2 carbon of the activated haloalkyne, assisted by a concerted proton abstraction by the triflate, and that the protodeauration is the turnover-limiting step, in agreement with an observed primary kinetic isotope effect.