title: On the thermal stability of [60]fullerene cycloadducts: retro-cycloaddition reaction of 2-pyrazolino[4,5:1,2][60]fullerenes.
abstract: 2-Pyrazolino[4,5:1,2][60]fullerenes undergo a thermally induced retro-cycloaddition process whose efficiency is influenced by the nature of the C-substituent. C-Aryl-N-Aryl-2-pyrazolino[60]fullerenes (2a-d) poorly undergo a thermal retro-cycloaddition reaction even in the presence of a strong dipolarophile or a metal Lewis acid which, in contrast to other fullerene derivatives, shows their remarkable thermal stability. C-Alkyl-N-Aryl-2-pyrazolino[60]fullerenes (2e-f) show a different behavior, being more vulnerable to the presence of copper triflate and leading to the retro-cycloaddition product (pristine C60) in good yield.
authors.affiliation: Departamento de Química OrgAnica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Delgado
authors.forename: Frédéric
authors.initials: F
authors.lastname: Oswald
authors.forename: François
authors.initials: F
authors.lastname: Cardinali
authors.forename: Fernando
authors.initials: F
authors.lastname: Langa
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín