A superacid (triflic acid) promoted dual C–C bond formation via intermolecular Friedel–Crafts alkylation (Michael addition type) and intramolecular acylation for the efficient synthesis of 3-substituted indan-1-ones is presented. This method was successful in activating ethyl cinnamates towards dual aromatic electrophilic substitution. Moreover, it enabled us to synthesize novel spirotetracyclic systems
gold(I)‐catalyzed synthesis of indanones from trimethylsilylacetylenes and acylsilanes is presented. The reaction is initiated through a synergistic acylsilane activation–gold acetylide formation and involves consecutive alkyne σ‐gold(I) addition, π‐activation, and 1,2‐migration of a silyl group. Studies performed on the reaction mechanism allowed to establish the nature of the silyl migrating group and invoke the