Metallkomplexe mit biologisch wichtigen Liganden LXXVI. Halbsandwichkomplexe von Cobalt(III), Iridium(III) und Ruthenium(II) mit Amiden von 2-Hydroxyiminocarbonsaeuren

Article abstract of DOI:10.1016/0022-328X(94)05257-C

The reactions of Cp^*Co(CO)I2, <(p-cymene)RuCl2>2 or *IrCl2>2 with the amide of 2-hydroxyiminopropionic acid and with N-(2-hydroxyiminopropionyl)amino acids gave the following chiral (N,O)- or (N,N)-chelate complexes: (1), (2), (3), (5), (6), (8), (9).The oxime of pyruvoyl methionine forms a (N,N,S)-trischelate complex 10.Complex 5a can be deprotonated in the presence of donors to yield the compounds (7, L=PEt3, PPh3, py).The structures of 4, 6b (R = CH3), 8a (R = H) and 8b (R = CH2Ph) have been determined by X-ray diffraction.Also the dipeptide complexes (11, R=H, CH2Ph) which are analogues of 8 have been prepared.The observed diastereospecific formation of 8b and 11b (R = CH2Ph) can be explained by a hydrogen bond between the oxygen atoms of the carboxyl and the amide group. Keywords: Cobalt; Iridium; Ruthenium; Half-sandwich complexes; Amide; 2-Hydroxyimino carboxylic acid