General One-step Synthesis of Symmetrical or Unsymmetrical 1,4-Di(organo)fullerenes from Organo(hydro)fullerenes through Direct Oxidative Arylation.

A general one-step synthesis of symmetrical or unsymmetrical 1,4-di(organo)fullerenes from organo(hydro)fullerenes (RC ₆₀ H) is realized by direct oxidative arylation. The new combination of catalytic trifluoromethanesulfonic acid (TfOH) and stoichiometric o -chloranil is the first to be used to directly generate an R-C ₆₀ ⁺ intermediate from common RC ₆₀ H. Unexpectedly, the in situ generated R-C ₆₀ ⁺ intermediate is shown to be quite stable in whole ¹³ C NMR spectroscopy characterization in the absence of cation quenching reagents. Because the direct oxidation of common RC ₆₀ H to form the corresponding R-C ₆₀ ⁺ has never been realized, the present combination of TfOH and o -chloranil solves the challenges associated with the formation of stable RC ₆₀ ⁺ cations from common RC ₆₀ H without any coordination of an R group.