Gold‐Catalysis: Highly Efficient and Regio‐Selective Carbonyl Migration in Alkynyl‐Substituted Indole‐3‐Carboxamides Leading to Azepino[3,4‐b]indol‐1‐ones

An unprecedented rearrangement/anellation sequence allows the clean synthesis of azepino3,4‐b]indol‐1‐ones from readily available starting materials. Alkyne‐substituted indole‐3‐carboxamides were prepared and converted to azepino3,4‐b]indol‐1‐ones by the SPhosAuNTf₂ catalyst (SPhos=2‐dicyclohexylphosphino‐2′,6′‐dimethoxybiphenyl). The new connectivity, which involves an unprecedented 3,2‐shift of an acylamino group for the product formation, was proven by a crystal structure analysis.