METAL-COMPLEXES OF BIOLOGICALLY IMPORTANT LIGANDS, CVI - METAL-COMPLEXES OF DONOR SUBSTITUTED OXAZOLONES AND OF BIS(OXAZOLONES)

A series of chelate complexes 1-12 of Cu(II), Ni(II), Pd(II), and Ru(I II) with the anion of 2-(2'-hydroxyphenyl)-5 (4H)-oxazolone and with 2 -(2'-aminophenyl)-5(4H)-oxazolone were prepared from metal salts or fr om chloro-bridged complexes [(R3P)MCl2](2) (M = Pd, Pt) and [(p-cymene )RuCl2](2). Nucleophilic addition of alpha-amino acid esters to the bi s-chelate complexes M(oxophenyloxazolone)(2) (M = Ni, Cu) gave the dip eptide derivatives 13-18. Dinuclear Pd(II) and Pt(II) chelate complexe s 19-23 were obtained from phenylene- and ethylene-bridged bis(oxazolo nes). The structures of (Et3P)(Cl)Pd(O,N-oxophenyloxazolone) (6) and o f (2,2'-phenylene-bis(4-methyloxazolone)Pt(PEt3)Cl-2 (20) were determi ned by X-ray diffraction. In complex 20 a close proximity of two pheny lene H atoms to the metal is observed.