“…Exohedral chemical functionalization of endohedral fullerenes has a great significance toward their potential applications. Although a large number of experimental studies on the chemical functionalization of empty fullerenes such as C 60 and C 70 have been already reported, methods developed for the exohedral functionalization of endohedral fullerenes are not so extended, and include photochemical reactions, Diels–Alder reactions, Prato reactions, Bingel-Hirsch reactions, radical addition reactions, and some other addition reactions. − ,,,,,, The chemical reactivity of fullerenes is mostly determined by their π-system, and in many reactions fullerenes behave as extended polyalkenes with rich addition chemistry. In the view of the multiple addition sites available at each carbon cage, the question of the regioselectivity of the chemical derivatization is one of the most challenging in fullerene chemistry.…”