Acid-Responsive Dissociation of Ferrocene Compounds: Diels-Alder Diene Equivalents for Selective Preparation of [60]Fullerene-Fused Bicyclo[2.2.1]hept-5-enes.

Herein, an unprecedented transformation of [60]fullerene with ferrocene compounds giving access to various [60]fullerene-fused bicyclo[2.2.1]hept-5-enes is presented. In the presence of an acid, ferrocene compounds undergo an unusual dissociation process and serve as Diels-Alder diene equivalents to react with [60]fullerene for the selective construction of a class of novel fullerene-fused bridged carbocyclic derivatives. The reaction is easy to perform and has a wide substrate scope as well as excellent functional group compatibility, representing a new application of ferrocene compounds in synthetic chemistry.