Copper(I)-Mediated Divergent Synthesis of Pyrroquinone Derivatives and 2-Halo-3-amino-1,4-quinones.

A divergent transformation of 2-amino-1,4-quinones for the synthesis of pyrroquinone derivatives and 2-halo-3-amino-1,4-quinones was disclosed. The mechanistic study showed that both the tandem cyclization and halogenation involved a Cu(I)-catalyzed oxidative radical process. This protocol not only constructed a series of novel pyrroquinone derivatives with high atom economy but also provided a new method of halogenation via directed C(sp 2 )-H functionalization with CuX (X = I, Br, Cl) serving as the X (X = I, Br, Cl) source.