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

Abstract

The reactions of Cp ★Co(CO)I 2, [( p-cymene)RuCl 2] 2 or [Cp ★IrCl 2] 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: ▪ ▪ ( 3) ▪ ( 6) ▪ ( 9) (R = H, CH 2Ph). 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 = PEt 3, PPh 3, py). The structures of 4, 6b (R = CH,), 8a (R = H) and 8b (R = CH 2Ph) have been determined by X-ray diffraction. Also the dipeptide complexes ▪ which are analogues of 8 have been prepared. The observed diastereospecific formation of 8b and 11b (R = CH 2Ph) can be explained by a hydrogen bond between the oxygen atoms of the carboxyl and the amide group.