Efficient cyclopropanation of [60]fullerene starting from bromo-substituted active methylene compounds without using a basic catalyst

Methanofullerene was synthesized via cyclopropanation of [60]fullerene with bromo-substituted active methylene compounds in the presence of amino acid and dimethyl sulfoxide without the use of a basic catalyst. This synthesis is a variation of the Bingel reaction that can be used for base-sensitive substrates. This method allows the cyclopropanation of [60]fullerene with various bromomalonates and bromoacetoacetates at room temperature.