Denitrogenative N–O Coupling of Benzyl Azides with <i>N</i> -Hydroxyphthalimide Mediated by Cerium(IV) Ammonium Nitrate as an Oxidant

An intermolecular N-O coupling process between iminyl radicals derived from benzyl azides and phthalimide-<i>N</i>-oxyl radicals, leading to the <i>O</i>-phthalimide oximes with a rare N-O-N fragment, was discovered. The present work reveals an unusual reactivity of organic azides: they are introduced into the denitrogenative generation of <i>N</i>-centered iminyl radicals via hydrogen atom abstraction from the α-position of the azide group. Moreover, the method exploits the dual reactivity of the phthalimide-<i>N</i>-oxyl radical, which acts both as a mediator of hydrogen atom abstraction and an interceptor of intermediate iminyl radicals.