Isolation and characterization of nine tris-adducts of N-methylfulleropyrrolidine derivatives.

We report the isolation and characterization of bis- and tris-adducts of fulleropyrrolidine derivatives. First, all eight N-methyl regioisomers with two addends on the C60 sphere have been isolated; second, C60 was used as starting material for the synthesis of tris-adducts, and the products formed in detectable quantities have been isolated and characterized. Third, the same compounds were obtained by introducing the third addend on each previously isolated bis-derivative: this approach facilitated the assignment of the relative geometry through chromatographic comparison of the diverse reaction mixtures. Finally, the obtained tris-adducts have been characterized by means of ES-MS, UV-vis, 1H NMR, as well as comparison with UV spectra and elution order of Bingel and Diels-Alder tris-adducts described in the literature.