Bromination-Mediated Regioselective Preparation of Cyclopentadienyl-Type [60]Fullerene Derivatives with Alkoxy, Peroxy, and Bromo or Hydro Addends

Bromine reacts with the 1,2-bisadduct C60(OOtBu)2 efficiently to form the cyclopentadienyl-type compound 4 (C60(OOtBu)2Br4). In the presence of AgClO4, the four bromine atoms can be replaced regioselectively by methoxyl groups in a stepwise fashion to form C60(OOtBu)2Br4−x(OMe)x. A second alcohol may be introduced by treating partially methoxylated compound 6 (C60(OOtBu)2Br2(OMe)2) with ROH/AgClO4. Other related reactions have been investigated to explore the reactivity patterns. The structure of compound 6 was confirmed by single crystal X-ray analysis.