Palladium-Catalyzed Aerobic Oxidative Coupling of ortho-(Alkynyl)styrenes with Allylic Alcohols via 6-endo-dig Cyclization: Regioselective Construction of Polysubstituted Naphthalenes

An efficient protocol is described for the regioselective construction of polysubstituted functionalized naphthalenes from easily accessible ortho-(alkynyl)­styrenes under mild reaction conditions. The reaction proceeds via cycloaromatization and intermolecular coupling of ortho-(alkynyl)­styrenes with allylic alcohols catalyzed by PdCl2. Notably, the reaction is successful under open air as the green oxidant source. A range of functional groups (F, Cl, Br, NO2, and ester) including protecting free OH groups were found to be compatible.