Copper‐Catalyzed C–H Alkynylation/Intramolecular Cyclization Cascade for the First Synthesis of Trifluoromethylated Pyrrolo[1,2‐a]quinolines

A highly efficient and simple route for the first synthesis of CF3-substututed pyrrolo[1,2-a]quinolines from quinolines, terminal alkynes, and methyl 4,4,4-trifluorobut-2-ynoate is reported. The noteworthy feature of this report is that the method involves a two-step protocol to synthesize tricyclic heterocycles in a one-pot fashion through CuI-catalyzed C–H alkynylation for the formation of alkynyl-substituted 1,2-dihydroquinolines, followed by a CuII-assisted intramolecular cyclization under air. This strategy tolerates a wide range of substrates with a variety of functional groups under mild conditions, and gives the products in good to excellent yields.