Palladium-Catalyzed Alkenylation via sp2 C-H Bond Activation Using Phenolic Hydroxyl as the Directing Group

This note describes the efficient and highly regioselective synthesis of 2-(2'-alkenylphenyl)phenol derivatives via palladium-catalyzed 2'-alkenylation of 2-arylphenols directed by the phenolic hydroxyl group using benzoquinone as the oxidant in an atmosphere of air. This reaction can tolerate a series of functional groups and provides the alkenylation products regio- and stereoselectively in moderate to good yields.