One-Pot Three-Component Synthesis of Phenanthrenes via Palladium-Catalyzed Catellani and Retro -Diels-Alder Reactions.

An efficient one-pot three-component palladium-catalyzed domino reaction of aryl iodide, 2-bromophenylboronic acid, and norbornadiene to produce phenanthrenes has been developed. Norbornadiene serves both as the activator of ortho -C-H bond and the source of ethylene via a retro -Diels-Alder reaction. The method features inexpensive and readily available substrates, a broad range of functional groups, and good yields.