Copper(II)-catalyzed C5 and C7 halogenation of quinolines using sodium halides under mild conditions.

A simple and mild protocol for copper catalyzed halogenation of quinoline at C5 and C7 positions was developed, affording the desired remote C-H activation products in moderate to good yields. This reaction proceeds with low-cost sodium halides (NaX, X = Cl, Br, I) and features excellent substrate tolerance. A series of control experiments were carried out to illustrate a single-electron-transfer process which plays a vital role in the halogenation.