Iron salt, a cheap, highly efficient and environment-friendly metal catalyst for Se–Se bond cleavage and the further reaction with methylenecyclopropanes under mild conditions

FeCl3 was found to be a good catalyst in Se-Se bond cleavage. Further electrophilic additions to methylenecyclopropanes provide a convenient access to diphenylselenylcyclobutanes. Comparing with other Lewis acids, FeCl3 is much cheaper and the reaction conditions are milde and more tolerance to air and moisture.