Abstract We describe a computational DFT investigation on the mechanism of the one‐pot synthesis of azepino‐indoles catalyzed by [Au(IPr)Cl]/AgOTf (IPr=1,3‐bis(2,6‐diisopropylphenyl‐imidazol‐2‐ylidene) by the simultaneous construction of the pyrrolyl and seven‐membered rings. The mechanism of the final ring‐closing event is elucidated, which reveals the counterion‐assisted nucleophilic trapping of the carbonyl moiety by the alkenyl‐gold species formed in situ. The computational evidence supports the labeling control experiments and highlights the presence of a cyclopropyl‐gold‐carbenoid intermediate in the final intramolecular 1,3‐hydrogen‐shift/skeleton‐rearrangement sequence.