Benzene rings of N-alkyltoluidine and benzene (or iodobenzene) in acetic acid were annelated with acetylenedicarboxylates by palladium (II) acetate to give N-alkylindole-2, 3- dicarboxylate and naphthalene-1, 2, 3, 4-tetracarboxylate. The formation of the products are explained in terms of toluidine radical cation intermediates.
