Krämer, Roland; Maurus, Michael; Bergs, Ralph; Polborn, Kurt; Sünkel, Karlheinz; Wagner, Barbara; Beck, Wolfgang (1993): Metallkomplexe mit biologisch wichtigen Liganden, LXV. Chirale Halbsandwich-Komplexe von Cobalt(III), Rhodium(III), Iridium(III) und Ruthenium(II) mit -Aminosäureamid-, Glycinnitril- und Peptidester-Liganden. In: Chemische Berichte, Vol. 126, Nr. 9: S. 1669-1980




Cp*Co(CO)I2 (Cp* = 5-C5Me5), [(6-arene)RuCl2]2 (arene = p-cymene, hexamethylbenzene), and [Cp*MCl2]2 (M = Rh, Ir) react with -amino amides and various peptide esters to give the N,O-chelate complexes [Cp*(I)Co - NH2C(H)(R1)C(NHR2)-O]+ (1), [(6-arene)(Cl)Ru - NH2C(H)(R1)C(NHR2)O]+ (2), and [CP*(Cl)M - NH2CH2C(NHR)O]+ (M = Rh, Ir) (5, in solution), respectively. In the solid state the ligands are 1N-bonded in 5. By deprotonation of the peptide bond in 2 and 5 the neutral N, N-chelate complexes (6-arene)(Cl)Ru - NH2C(H)(R1)C(O)-2 (6) and Cp*(Cl)M - NH2C(H)(R1)C(O)NR2 (M = Rh, Ir) (7) have been obtained. Glycinenitrile is 1-bonded in (6-p-cymene)(Cl)2Ru(NH2CH2CN) (3) and Cp*(Cl)2Rh(NH2CH2CN) (4). Double deprotonated triglycine methyl ester is a N,N,N-tridentate ligand in (6-C6Me6)Ru(NH2CH2C(O)NCH2C(O)-NCH2CO2Me) (8). The anions of L-asparagine and of aspartame (L-aspartyl-L-phenylalanine methyl ester) give the complexes 9-12 with tridentate O,N,O- or O,N,N-chelate ligands. The crystal structures of 1d (L = glyglyOEt), 5a (L = glycinamide), 6e (L = glyglyOEt), and 7k (L = glyglyglyOEt) have been determined by X-ray structural analysis.