Fullerene Unsymmetrical Bis-Adducts as Models for Novel Peptidomimetics

Abstract

Two classes of unsymmetrical, orthogonally protected bis-fulleropyrrohdine amino acids have been prepared as models for fullerene-based peptidomimetics with the carbon sphere inserted into the peptide backbone Two successive [3+2] cycloadditions of azomethine ylides (thermally generated from formaldehyde and the corresponding orthogonally protected glycino-amines and -acids) to C(60) afforded NHFmoc/CO(2)tBu and NHBoc/CO(2)Me fulleropyrrolidine couples, offering the possibility of selective deprotection under both acidic and basic conditions In both classes of unsymmetrical bis-adducts, the distribution of all the trans (t(1)-t(4)) and equatorial (e' and e '') isomers was quite similar except. for the t(3) NHBoc/CO(2)Me compound, which rapidly decomposed during chromatography All compounds were characterized by UV/Vis, (1)H and (13)C NMR spectroscopy, and mass spectrometry