Arylation of Benzo-Fused 1,4-Quinones by the Addition of Boronic Acids under Dicationic Pd(II)-Catalysis

The first examples of the direct arylation of benzo-fused 1,4-quinones by the dicationic Pd(II)-catalyzed addition of arylboronic acids are reported. The addition reaction is carried out under very mild conditions (dioxane-H2O, rt, open air atmosphere) and is tolerant of free OH groups. In addition, the reaction shows high regioselectivity when using nonsymmetrical quinones as starting materials.
Projects UCM-BSCH GR58/08-910815 and CTQ2006-15279-C03-01 (both to A.G.C.), and SAF2006- 04698 (to M.T.M.), are gratefully acknowledged for financial support.