Stereoelectronic effects in diastereoselective formation of fulleroids

The substituent effects on diastereoselective formation of fulleroids in the reactions of C(60) with various unsymmetrical diazoalkanes were investigated. The steric demand on the stereochemical course of reactions dominated the diastereoselectivity for diazoalkanes bearing aliphatic as well as monosubstituted pi-resonating groups, whereas the stereoelectronic effects of coexisting pi-resonating aromatic and cyclopropyl groups played a crucial role in the ring closure of the radical intermediates, overriding the steric demand.