FIGR ID=jo070161mn00001> figures/jo070161mn00001.gif" ALIGN="left" HSPACE=5> |
Isoxazolino[4,5:1,2][60]- and -[70]
fullerenes un
dergo an e
fficient retro-cycloaddition reaction to pristine
fullerene by thermal treatment in the presence o
f an excess o
f a dienophile and Cu(II) catalysis, whichcan be selectively used in the presence o
f malonate or pyrrolidine cycloadducts. Trapping experimentsusing
N-phenylmaleimi
de as dipolarophile have shown that the reaction mechanism occurs by thermalremoval o
f the nitrile oxi
de 1,3-dipole, in a process which is
favored by the presence o
f 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, isoxazolino
fullerenes were stable un
der oxidative conditions.
