Synthesis of Novel Heterocycles by Amide Activation and Umpolung Cyclization.

Herein, we report a metal-free synthesis of cyclic amidines, oxazines, and an oxazinone under mild conditions by electrophilic amide activation. This strategy features an unusual Umpolung cyclization mode and enables the smooth union of alpha-aryl amides and diverse alkylazides, effectively rerouting our previously reported alpha-amination transform.