Palladium-catalyzed cascade cyclization of α,β-unsaturated N-tosylhydrazones with iodoarenes: access to 2H-chromenes and 2H-quinolines†

A palladium-catalyzed cascade reaction of α,β-unsaturated N-tosylhydrazones with iodoarene derivatives containing a nucleophilic group has been developed, which provides facile access to 2H-chromenes and 2H-quinolines, respectively. Additionally, the double Pd–carbene migratory insertion/nucleophilic substitution processes for the synthesis of a ternary heterocyclic skeleton were possible in the developed catalytic system.