Amination of [60]fullerene by ammonia and by primary and secondary aliphatic amines - Preparation of amino[60]fullerene peroxides

Ammonia and aliphatic amines react readily in the oxygen-rich regions of the C_s symmetric fullerene peroxides C₆₀(O)(OOtBu) ₄ (1) and C₆₀(OH)(Br)(OOtBu)₄ (2c). Michael addition-type hydroamination of the 1,4-diene moiety on the central skewpentagon was observed when 1 was treated with ammonia or with nonbulky primary amines, while sterically demanding primary amines opened the epoxy moiety to form vicinal aminohydroxy fullerene compounds with the amino group on the central pentagon. In 2c the bromo group was replaced under similar conditions by ammonia and primary amines. Cyclic secondary amines showed different reaction patterns, forming hydrogenation products or aminoketal-fullerenes when treated with 1 and 2c, respectively. Single-electron transfer (SET) is the key step in all the proposed mechanisms. The compounds were characterized by their spectroscopic data, and in addition, three single-crystal X-ray structures were obtained.