Exohedral functionalization of [60]fullerene by [3+2] cycloadditions: Syntheses and chemical properties of triazolino-[60]fullerenes and 1,2-(3,4-dihydro-2H-pyrrolo)-[60]fullerenes

The reaction of C60 with aryl azides 5 in dichlorobenzene at room temperature leads to isolable triazolinofullerene derivatives 6a and 6b. Photolysis of 6 selectively yields the aziridinofullerenes 7. In contrast to the photolysis the thermolysis affords the azafulleroids 8 as main product next to C60. In addition the first photochemically induced rearrangement of azafulleroids (1,6-aza-bridged isomers) to aziridinofullerenes (1,2-aza-bridged isomers) is described. Beside aziridines 7 the photochemical reactions of azides 5 with C60 predominantly yield one novel Cs symmetrical bisadduct, respectively. Furthermore the syntheses of symmetrical 1,2-(3,4-dihydro-2H-pyrrolo)-[60]fullerenes 12a-c by [3+2] cycloaddition of nitrile ylides 11 are reported.