Triazole-Directed Pd-Catalyzed C(sp2)–H Oxygenation of Arenes and Alkenes

Selective Pd-catalyzed C­(sp2)–H oxygenation of 4-substituted 1,2,3-triazoles is described. Unlike previous metal-catalyzed C–H functionalization events, which preferentially occur at the activated heterocyclic C–H bond, the regioselective oxygenation of the arene/alkene moiety is now achieved featuring the unconventional role of a simple triazole scaffold as a modular and selective directing group.