Sequential Tether-Directed Synthesis of New [3 : 2 : 1] Hexakis-Adducts of C60 with a Mixed Octahedral Addition Pattern

A new concept for the regioselective synthesis of 3 : 2 : 1] hexakis-adducts of fullerene C₆₀ was developed. Based on sequential tether-directed remote functionalizations, chiral 3 : 2] pentakis-adducts with an incomplete octahedral addition pattern were synthesized via stepwise cyclopropanation of C₆₀ with suitable macrocyclic tri- and bifunctional cyclomalonate tethers. The four resulting stereoisomers were isolated using chiral HPLC. The corresponding pairs of enantiomers show mirror image behavior in their CD-spectra. The pentakis-adducts served as suitable building blocks for the spatially controlled synthesis of mixed hexakis-adducts. Implementation of functional group-bearing monomalonates afforded octahedral 3 : 2 : 1] hexakis-adducts suitable for the construction of larger molecular and supramolecular fullerene architectures in excellent yield.