Sc3N@C78: Encapsulated Cluster Regiocontrol of Adduct Docking on an Ellipsoidal Metallofullerene Sphere

The first N-tritylpyrrolidino derivatives of D3h (78:5) Sc3N@C78 were successfully synthesized and isolated. The addition sites for the two nearly equivalent kinetic monoadducts 1a and 1b are across two different 6,6 junction sites on the Sc3N@C78 cage that are offset from the horizontal plane defined by the Sc3N cluster. The adducts were characterized by NMR experiments, DFT calculations and X-ray crystallographic analysis of Sc3N@C78 derivative 1a. A unique finding of this study is the regiocontrol of adduct docking by the internal Sc3N cluster.