Iso
xazolino[4,5:1,2][60]- and -[70]fullerenes undergo an efficient retro-cycloaddition reaction to pristinefullerene by thermal treatment in the presence of an e
xcess of a dienophile and Cu(II) catalysis, whichcan be selectively used in the presence of malonate or pyrrolidine cycloadducts. Trapping e
xperimentsusing
N-phenylmaleimide as dipolarophile have shown that the reaction mechanism occurs by thermalremoval of the nitrile o
xide 1,3-dipole, in a process which is favored by the presence of Cu(II) as thecatalyst. The ESI-MS study supports the observed retro-cycloaddition process for both C
60 and C
70derivatives. In contrast to previous electrochemical retro-cycloaddition processes observed in fulleropyrrolidines, iso
xazolinofullerenes were stable under o
xidative conditions.