METAL-COMPLEXES WITH BIOLOGICALLY IMPORTA NT LIGANDS .76. HALF-SANDWICH COMPLEXES OF COBALT(III), IRIDIUM(III) AND RUTHENIUM(II) WITH AMIDES OF 2-HYDROXYIMINOCARBOXYLIC ACIDS

The reactions of CpCo(CO)I-2, [(p-cymene)RuCl2](2) or [Cp*IrCl2](2) w ith the amide of 2-hydroxyiminopropionic acid and with N-(2-hydroxyimi nopropionyl)amino acids gave the following chiral (N,O)- or (N,N)-chel ate complexes: [Cp(I)Co-N(OH)=C(CH3)C(NH2)O] I (1), (p-cymene)(Cl)Ru- N(OH)=C(CH3)C(NH2)O]Cl (2); [Cp(Cl)Ir-N(OH)=C(CH3)C(NMe(2))O]Cl (3), Cp(I)Co-N(O)=C(CH3)C(NH2)O (4), Cp*(Cl)Ir-N(OH)=C(CH3)C(O)NR (5), (p- cymene)(Cl)Ru-N(OH)=C(CH3)C(O)NR (6) (R = H, CH3) Cp(Cl)Ir-N(OH)=C(CH 3)C(O)NCH(R)COOH (8), (p-cymene)(Cl)Ru-N(OH)=C(CH3)C(O)NCH(R)COOH (9) (R = H, CH(2)Ph). The oxime of pyruvoyl methionine forms a (N,N,S)-tri schelate complex 10. Complex 5a can be deprotonated in the presence of donors to yield the compounds Cp(L)Ir-N(O)=C(CH3)C(O)NH (7, L = PEt( 3), PPh(3), py). The structures of 4, 6b (R = CH3), 8a (R = H) and 8b (R = CH(2)Ph) have been determined by X-ray diffraction. Also the dipe ptide complexes Cp(Cl)Ir-NH2CH(CH3)C(O)NCH(R)COOH (11, R = H, CH(2)Ph ) which are analogues of 8 have been prepared. The observed diastereos pecific formation of 8b and 11b (R = CH(2)Ph) can be explained by a hy drogen bond between the oxygen atoms of the carboxyl and the amide gro up.