I₂/TBHP-mediated oxidative cascade cyclization of vinyl azide and benzylamine to construct 2,5-disubstituted oxazoles

A one-pot facile synthesis of disubstituted oxazoles has been achieved from vinyl azide and benzylamine. A coherent mixture of iodine and tert-butyl hydroperoxide (TBHP) efficiently promoted oxidative cascade cyclization to construct 2,5-disubstituted oxazoles under aerobic conditions. Notably, the oxidative cyclization involves feasible C(sp³)-functionalization with the elimination of the azide group as the intermediate step. In consequence, the consecutive C-N and C-O bond formations lead to a variety of disubstituted oxazole derivatives. Moreover, the one-pot methodology features a metal-free strategy, readily available reagents, shorter times, good yields, and mild reaction conditions.