Access to congested quaternary centers by Pd-catalyzed intermolecular γ-arylation of unactivated α,β-unsaturated aldehydes

A palladium-catalyzed intermolecular γ-arylation of γ-branched α,β-unsaturated aldehydes has been developed. The reaction allows congested quaternary centers to be forged on a remote position from the carbonyl group, affording a variety of products in high yield and with consistently high stereoselectivity using very low catalyst loadings. The synthetic utility of the products has been highlighted by a series of derivatizations and the potential of the method to be extended to remote ε-functionalization has been demonstrated.