Cu(I)-Catalyzed Alkynylation of Quinolones

Herein we report the first alkynylation of quinolones with terminal alkynes under mild reaction conditions. The reaction is catalyzed by Cu­(I) salts in the presence of a Lewis acid, which is essential for the reactivity of the system. The enantioselective version of this transformation has also been explored, and the methodology has been applied in the synthesis of the enantioenriched tetrahydroquinoline alkaloid cuspareine.