Palladium-Catalyzed Synthesis of Carbo- and Heterocycles through Norbornene-Mediated ortho C-H Functionalization

Direct aromatic functionalization based on the use of a palladium catalyst and norbornene is a useful method to achieve straightforward synthesis of carbo- and heterocyclic compounds. New ring formation occurs through a cascade process triggered by ortho C-H alkylation (inter- and intramolecular) or arylation (homo­- and heterocoupling) of aryl iodides. Up to four new carbon-carbon bonds are generated under palladium control in a single operation.