Addition of azomethine ylides to C60: synthesis, characterization, and functionalization of fullerene pyrrolidines

We report herein a new and very general fullerene functionalization, based on the 1,3-dipolar cycloaddition of azomethine ylides to C[sub 60]. Azomethine ylides, planar species of general formula (R[sup 1]R[sup 2])-C=N[sup +](R[sup 3]) - C[sup [minus]](R[sup 4]R[sup 5]), represent one of the most reactive and versatile classes of 1,3-dipoles. They can be generated from a wide variety of easily accessible starting materials and react readily with a range of dipolarophiles. The products of cycloaddition, substituted pyrrolidines, are well suited for further functionalization. A very easy way of generating azomethine ylides is the [open quotes]decarboxylation route.[close quotes] Another approach to azomethine ylides, the thermal ring-opening of aziridines, gave the same profitable results. The present new fullerene functionalization offers high potential in the materials chemistry field. Of the several uses that can be envisioned, two representative examples are reported. 17 refs., 1 fig.