Copper-Catalyzed Trifluoromethylation of Ynones Coupled with Dearomatizing Spirocyclization of Indoles: Access to CF₃-Containing Spiro[cyclopentane-1,3′-indole]

A one-pot protocol for the Cu(I)-catalyzed difunctionalization of indolyl ynones has been achieved via trifluoromethylation of alkyne followed by dearomatizing spirocyclization of indoles. This cascade process enables constructing diverse CF3-containing spiro[cyclopentane-1,3′-indole] scaffolds in moderate to excellent yields which have challenging quaternary spirocyclic carbon and tetrasubstituted alkenes.