Copper-Catalyzed Synthesis of N -Fused Quinolines via C(sp 3 )-H Activation-Radical Addition-Cyclization Cascade.

A novel copper-catalyzed cyclization reaction for the synthesis of pyrazolo[1,5- a ]quinoline, triazolo[1,5- a ]quinoline, and pyrrolo[1,2- a ]quinoline derivatives is described. The process is initiated by di- tert -butyl peroxide-mediated C(sp 3 )-H activation to generate the α-functionalized radical, which supervenes a cascade radical addition/cyclization sequence to access the N -fused quinolines in good yields with broad functional group tolerance.