Studies On The Cycloadditions Of [60]Fullerence And Endohedral Metallofullerene Sc₃N@C₈₀（I_h）

Chemical modification of [60]fullerene is an important research subject in fullerene chemistry. By now, numerous fullerene products with widely structural diversities have been prepared, and exhibit immense and potential applications in nanoscience, optoelectronic materials, solar cell and biomedicine. Therefore, the functionalization of C6o continuously affording a series of novel and available derivatives for further application is still an urgent and challenging task. In this dissertation, the main work presented is focused on these aspects, involving Mn(OAc)3·2H2O, Fe(ClO)4·H2O-mediated free-radical addition reaction, and the cycloaddition reaction of endohedral metallofllerene Sc3N@C8o(Ih) with benzyne and aryl azide, respectively.1. On the basis of our previous research, the free-radical reaction promoted by Mn(OAc)3·2H2O is further investigated. The addition of aluminum chloride to manganese acetate-mediated radical reaction of [60]fullerene with2-benzylmalonates,2-arylmalonates and2-arylcyanoacetates can switch the reaction pathway, and selectively affords various of structurally novel annulated products, that is,[60]fullerene-fused tetrahydronaphthalenes and indanes derivatives. The experiment results indicated that aluminum chloride played a key role in this reaction. The Friedel-Crafts-type annulation could occur after the radical addition and followed to generate the scarce adducts. In addition, the influence of different oxidants and the substituent groups was also investigated.2. A series of novel [60]fullerene-fused oxazolidine derivatives was synthetized by the Fe(ClO)4·xH2O-based radical reaction of C60with various N-sulfonyl and aryl aldimines. Compared with the reaction that N-sulfonyl and aryl aldimines generated in situ by sulfamides and aryl aldehydes in one pot, we found the direct reaction of C6o with N-sulfonyl and aryl aldimines in the presence of iron(Ⅲ) perchlorate gave superior results in distribution and yields of the products. We also investigated the influence of various substituted groups, and the arylation of the oxazolidine derivatives was also successfully carried out.3. The [2+2] cycloaddition reaction of endohedral metallofullerene Sc3N@C80(Ih) with4,5-diisopropoxybenzyne generated in situ from2-amino-4,5-diisopropoxybenzoic acid and isoamyl nitrite was systemically investigated. The [5,6]-and [6,6]-monoadducts with a four-membered ring were obtained under inert atmosphere. These two isomers are very stable, and there is no retro-addition or isomerization in thermalization. However, the reaction afforded an intriguing and unprecedented open-cage metallofullerene with the largest orifice yet encountered for endohedral metallofullerenes under an aerobic atmosphere. Its structure was unequivocally determined by X-ray single-crystal analysis. This work should promoted further studies on open-cage metallofullerenes. The formation of Sc3N@C8o(Ih) fused-lactone in the presence of Et3N was also studied.4. The azide addition to trimetallic nitride endohedral metallofullerene was first reported. The photoreaction and the thermal reaction of Sc3N@C8o(Ih) with4-isopropoxyphenyl azide were explored, respectively. Photoirradiation only afforded [6,6]-monoadduct, while the thermal reaction could give [5,6]-monoadduct along with [6,6]-isomer, and an unexpected bisadduct depending on the reaction temperature. According to UV-Vis-NIR. absorption spectroscopy and computational analysis, both [5,6]-and [6,6]-isomers were open azafulleriod, the former was established by X-ray single-crystal structure. The experiment disclosed that the [5,6]-azafulleriod was a thermodynamically isomer, while [6,6]-isomer was a kinetic product, and both retro-addition and isomerization could proceed under heated conditions. For detailed structural characterization of [6,6]-isomer and the structure of the bisadduct, X-ray crystallographic analysis is ongoing. The present work should pave the way for the synthesis of endohedral metallofullerene adducts with a variety of unique stuctures, including bis-, tri-and multiadducts, even accomplish the chemical synthesis of endohedral azametallofullerene.