Metal Complexes of Biologically Important Ligands, XCl. Introduction of Organometallic Fragments into α-Amino Acids by Reactions of α-Bromoglycine Derivatives with Anionic Organotransition-Metal Compounds

The reactions of protected α-bromoglycine esters R1(O)CNHCH(Br)CO2R2 (R1Ph, OCMe3; R2 Me, tBu) with organometallic anions of acetylferrocene, CpFe(CO)(PPh3)-C(O)CH3, (OC)5MC(OMe)CH3 (MCr, W), (OC)3Cr(η6-diphenylmethane), (OC)3Cr[η6-fluorene), (OC)3Cr(η6-dihydroanthracene) and of (OC)3Cr(-η6aniline) and (OC)3Cr(η6-o-toluidine) provide a method for the introduction of organometallic fragments into the side chains of α-amino acids.The complexes may be useful as markers for α-amino acids in peptides.The compound (OC))3Cr(η-o-C6H4(CH3)NHC-(H)(CO2Me)NHC(O)Ph was characterized by X-ray diffraction.