Selective Formation of a Symmetric Sc3N@C78 Bisadduct: Adduct Docking Controlled by an Internal Trimetallic Nitride Cluster

In this paper we report a regioselective Bingel−Hirsch reaction of Sc 3 N@C 78 yielding a single mono- and a dominate bis-ethyl malonate derivative for the first time. The C s -symmetric monoadduct 1 and C 2 v -symmetric bisadduct 2 were isolated by HPLC and characterized by MS, UV−vis, and NMR spectroscopy. The symmetric bisadduct 2 clearly demonstrate the remarkable regioselectivity control exerted by the encapsulated Sc 3 N cluster. We have employed a LUMO electron density surface computational approach to predict multiadduct docking sites on the ellipsoidal fullerene cage surface.