Reagent-Controlled Oxidative Aromatization in Iodocyclization: Switchable Access to Dihydropyrazoles and Pyrazoles

Switchable access to dihydropyrazoles and pyrazoles has been developed from common hydrazides by reagent-controlled iodocyclization. Controlling the oxidative aromatization in iodocyclization for heterocycles is reported for the first time, and this methodology maximally utilizes the dual nature of iodine.