[(η5-C5H5)Fe(CO)2](Fp)- complexes of the parabanic acid mono- and dianion: Synthesis, X-ray structures and reactivity of the heterocyclic ligand

Article abstract of DOI:10.1016/j.poly.2004.02.015

[(η⁵-C₅H₅)Fe(CO)₂](Fp)- complexes of the parabanic acid mono- and dianion have been synthesised in a photochemical reaction of FpI with parabanic acid and diisopropylamine in benzene. The former contains a reactive N(3)-H bond and can be readily thallated with TlOEt. Reaction of the thallated complex with Ph₃PAuCl, benzyl chloride and ethyl bromoacetate in DMF gave N(3)-aurated, N(3)-benzyl and N(3)-carboethoxymethyl complex, respectively. The structures of these complexes were confirmed by X-ray diffraction. The ester function in the N(3)-carboethoxymethyl complex was hydrolysed to afford air-stable, water-soluble acid, a potential metallocarbonyl labelling reagents for proteins.