Unprecedented ring expansion of [60]fullerene: incorporation of nitrogen at an open 6,6-ring juncture by regiospecific reduction of oxycarbonylaziridino-[2′,3′:1,2][60]fullerenes. Synthesis of 1a-aza-1(6a)-homo[60]fullerene, C60H2NH
Abstract
Upon treatment with zinc in glacial acetic acid, N-oxycarbonylaziridino[2′,3′: 1,2][60]fullerenes 3 undergo a reversible reductive cleavage of the bridgehead C–C bond to provide the first examples of birdged fulleroids 4 having an open 6,6-ring juncture; deprotection of the N-tert-butoxycarbonyl derivative 4a allows the convenient synthesis of C60H2NH 5, the parent member of this new class of bridged fulleroids.