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-H(2)O, 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.