Diastereospecific and Highly Site-Selective Functionalization of C₇₀ Fullerene by a Reaction with Diethyl N‑Arylaziridine-2,3-dicarboxylates

The diastereospecific and highly site-selective cycloaddition of N-arylazomethine ylides generated in situ from diethyl N-arylaziridine-2,3-dicarboxylates to C₇₀ fullerene is reported. The reaction provides C₇₀ fulleropyrrolidines in up to hundreds on a milligram scale as α- and β-adducts in a 4:1 ratio with a controlled stereochemical outcome: cis-aziridines give exclusively trans-adducts, and trans-aziridines give only cis-adducts. The ¹H and ¹³C­{¹H} NMR spectra for different isomeric adducts were recorded and analyzed to identify some characteristic features, which permit an easy identification of isomeric adducts of this type.