Synthesis of Polycyclic Chromene Cores through Gold (I)-Catalyzed Intramolecular Hydroarylation Reaction (IMHA)

A regioselective gold (I)-catalyzed approach for the construction of polycyclic chromene cores has been developed. The reaction proceeds in good to excellent yields under mild condition with a broad range of substrates providing a simple and efficient tool for the synthesis of pyranochromene derivatives. Moreover, the regiochemical control of the annulation of unsymmetrically substituted propargylic ethers has been investigated focusing on electronic/steric effects of the ligands of gold complexes as well as on the electronic effects of the groups on the aromatic rings.