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

Abstract

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.