Unsymmetrical Aryl-Aryl Cross-Coupling Leading to 6H-Dibenzopyrans.

6H-Dibenzopyrans are prepared starting from ortho-substituted aryl iodides, o-bromophenols and activated olefins, in the presence of a catalytic system based on palladium acetate and norbornene by means of a simple and efficient, one-pot, three-component procedure under mild conditions