[2+1] Cycloaddition of Nitrene onto C₆₀ Revisited: Interconversion between an Aziridinofullerene and an Azafulleroid

An open and closed case: The reversible interconversion of a [1,2]aziridinofullerene and a [1,6]azafulleroid represents the first such example for a monosubstituted fullerene. While the [1,2]aziridinofullerene rearranges thermally to the [1,6]azafulleroid, the [1,6]azafulleroid rearranges photochemically to the [1,2]aziridinofullerene in high yield (see picture).