The Activation of the Precatalyst Au–Cl Bond in the Cycloisomerization of Propargylamides: The Role of Hydrogen Bonding

Herein we describe our findings dealing with the activation of the Au–Cl bond in [Au(L)Cl] complexes with several additives. We have probed several additives for their ability to promote the activation of the Au–Cl bond, in a prototypical cationic Au(I)‐mediated reaction, namely the cyclization/cycloisomerization of propargylamides. Phenol was found to be an efficient additive, successfully promoting the activation of the gold precatalysts, and the progression of the reaction, under mild conditions. Further studies on the reactivity of several substrates and the kinetic profile of the reaction provide valuable insight to the phenol‐mediated activation of Au–Cl bond and its catalytic competence. Density functional theory calculations provided additional details regarding the effect of the studied additives.