Reagent scope of reaction^a.

^aReaction conditions: 1a (0.5 mmol), o-dihalo substrate (1.5 eq.), Fe₂O₃ (20% mol), K₂CO₃ (1 eq.), DMEDA (20%) were added to PhMe (2 mL) and react at 110 °C for 48 h under N₂.