[60]Fullerene–acene chemistry: a review

Acenes represent interesting platforms on which to add [60]fullerenes via Diels–Alder cycloaddition reactions. For unsubstituted acenes, the most reactive positions are the center-most rings. Large acenes can accommodate more than one [60]fullerene cycloaddition and these reactions become facile once suitable directing substituents (e.g. phenyl groups) are added to the acene. In these cases, [60]fullerenes add in a syn -diastereoselective fashion due to favorable π–π stacking interactions between adjacent [60]fullerene moieties. The π–π stacking interactions provide further stabilization to these adducts. Several cis -bis[60]fullerene–acene adducts have been prepared in modest to excellent yield and one cis , cis -tris[60]fullerene–heptacene adduct has also been prepared. .