Samarium(II)-mediated spirocyclization by intramolecularaddition of arylradicals onto an aromatic ring was achieved by the reaction of N-(2-iodophenyl)-N-alkylbenzamides with SmI2 in the presence of HMPA, yielding spirocyclic indolin-2-one derivatives. The ether congeners afford spirocyclic benzofuran derivatives in moderate yields by arylradicaladdition onto a benzene ring without having an electron-withdrawing