2-Nitroferrocenyloxazolines: precursors to nitrofulvalenes and derivatives of (pS)- and (pR)-2-aminoferrocenecarboxylic acids

Diastereoselective lithiation of (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline, followed by addition of N₂O₄, gave (S)-2-(_pS)-2-nitroferrocenyl]-4-(1-methylethyl)oxazoline which was subsequently converted into derivatives of (_pS)-2-aminoferrocenecarboxylic acid. The corresponding (_pR)-derivatives were obtained through use of a removable TMS blocking group. The 2-nitroferrocenyloxazolines produced in this work underwent facile photo-decomplexation to give 2-nitrocyclopentadienyliden-1,3-oxazolidenes.