A palladium-catalyzed, norbornene-mediated ortho-alkylation reaction of aryl iodides with secondary alkyl halides is described. Intermolecular or intramolecular ortho-alkylation proceeds in a domino process with various termination steps, generating two new carbon− carbon or carbon− nitrogen bonds in one pot, to afford an array of polycyclic heterocycles. The use of enantioenriched substrates has shown that this palladium-catalyzed reaction is ...