Denitrogenative N–O Coupling of Benzyl Azides with N -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-N-oxyl radicals, leading to the O-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 N-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-N-oxyl radical, which acts both as a mediator of hydrogen atom abstraction and an interceptor of intermediate iminyl radicals.