Pd-Catalyzed Sequential C–C Bond Formation and Cleavage: Evidence for an Unexpected Generation of Arylpalladium(II) Species

A Pd­(II)-catalyzed reaction engaging alkenyl β-keto esters is reported that leads to the formation of 1-naphthols and an unexpected generation of arylpalladium­(II) species. Interception of the in situ generated arylpalladium­(II) species in a Mizoroki–Heck reaction, together with additional mechanistic studies, provided strong evidence in support of the first aromatization-driven β-carbon elimination process. A single Pd catalyst served to promote a series of both C–C bond forming and cleavage events in an unprecedented manner.