Ring-opening reactions of diarylvinylidenecyclopropanes by iodine and bromine

Diarylvinylidenecyclopropanes undergo a novel ring-opening reaction upon treatment with iodine or bromine at 0–25 °C in 1,2-dichloroethane to give the corresponding iodinated or brominated naphthalene derivatives in good to high yields within 3 h. The further transformation of the corresponding iodinated or brominated naphthalene derivatives has been disclosed.