Iodine-Catalyzed Direct C-H Alkenylation of Azaheterocycle N-Oxides with Alkenes.

An efficient and regioselective alkenylation of azaheterocycle N-oxides with alkenes catalyzed by iodine under metal- and external oxidant-free reaction conditions has been developed. A variety of (E)-2-styrylazaheterocycles have been produced in moderate to excellent yields. The mechanistic exploration indicated that the N-oxide group played dual roles as both the directing group and an internal oxidant in this catalytic cycle.