CuX-Activated N-Halosuccinimide: Synthesis of 3-Haloquinolines via Electrophilic Cyclization of Alkynyl Imines.

We report an electrophilic cyclization of alkynyl imines to afford polysubstituted 3-haloquinolines using CuX-activated N-halosuccinimdes (NXS) as electrophiles. Control experiments demonstrated that the NXS/CuX system might be more active than single NXS and could be applied in the electrophilic cyclization of electron- deficient substrates.