Palladium-Catalyzed Carbonylative Cyclization of Aryl Alkenes/Alkenols: A New Reaction Mode for the Synthesis of Electron-Rich Chromanes

The Pd­(II)-catalyzed intramolecular carbonylative cyclization reaction of aryl alkenes and aryl alkenols is reported for the synthesis of structurally diverse chromanes. PdCl<sub>2</sub>(CH<sub>3</sub>CN)<sub>2</sub> was used as the catalyst and CuCl<sub>2</sub> as the oxidant under the balloon pressure of CO. The reaction is conducted under mild conditions, and chromane-type esters and lactones can be generated in a highly regio- and stereoselective manner.