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 C-60(OOtBu)(2) efficiently to form the cyclopentaciienyl-type compound 4 (C-60(OtBu)(2)Br-4). In the presence of AgClO4, the four bromine atoms can be replaced regioselectively by methoxyl groups in a stepwise fashion to form C-60(OOtBu)(2)Br4-x(OMe)(x). A second alcohol may be introduced by treating partially methoxylated compound 6 (C-60(OOtBu)(2)Br-2(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.