Co-catalyzed radical cycloaddition of [60]fullerene with active dibromides: selective synthesis of carbocycle-fused fullerene monoadducts.

An efficient and highly selective Co-catalyzed radical cycloaddition of [60]fullerene with active dibromides for the synthesis of three-, five-, six-, and seven-membered carbocycle-fused fullerene monoadducts has been reported. The controlled experiments unambiguously disclosed that the reaction proceeds through the formation of a fullerene monoradical as a key intermediate.