Palladium-Catalyzed α-Arylation of Vinylogous Esters for the Synthesis of γ,γ-Disubstituted Cyclohexenones

A palladium-catalyzed α-arylation of cyclic vinylogous esters to form products that are converted in one step to γ-alkyl-γ-aryl-substituted cyclohexenones is reported. This Pd-catalyzed reaction proceeds at room temperature, is generally high-yielding, and uses an amount of a commercially available catalyst as low as 0.25 mol %. The scope of aryl bromides is particularly broad, and alkenyl bromides can also be used. This two-step protocol, comprising α-arylation and reductive transposition, can be performed in one pot and is applicable to gram-scale synthesis.