Conjugated Fullerenes

Significance

The first examples of fullerene structures conjugated directly with unsaturated addends are reported. Structures such as 2a (an open [5,6] sp^² carbon bridged fullerene) are of ­interest as it may be possible to alter the electronic properties of the C₆₀ unit through direct conjugation with external moieties. Using previously reported diazirines to form [5,6]- and [6,6]-adducts 1a and 1b allowed for elimination of HCl in the final step and resultant formation of the desired exo­cyclic double bond.