Reactivity Of Quinoline-8-Carbaldehyde Toward Platina-Beta-Diketone And Acetyl(Amine)Platinum(Ii) Complexes. Formation Of Acyl(Hydroxyalkyl)Platinum(Iv)

The reaction of the platina-beta-diketone [Pt-2{(COMe)(2)H}(2)(mu-Cl)(2)] (1) with quinoline-8-carbaldehyde (C9H6NCHO) in MeOH/H2O (Pt/C9H6NCHO = 1/2) leads to the cleavage of the chloride bridges in 1 with acetaldehyde displacement. and to the formation of the acetylacyl(hydroxyalkyl)platinum(IV) complex [Pt(COMe)Cl(C9H6NCO-kappa N,kappa C)(C9H6NCHOH-kappa N,kappa C)] (3) as a single diastereomer (OC-6-46). Water-assisted activation of the OC-H bond of one aldehyde and H transfer to the oxygen atom of the second aldehyde occurs. In the presence of sodium methoxide, dehydrochlorination of the platinum starting material affords the dinuclear [Pt-2(C9H6NCO-kappa N,kappa C)(2)(mu-COMe)(2)] (4) with acetyl bridges in a head-to-tail fashion. Pyridine or tetrahydrofuran fail to cleave the acetyl bridges, which are readily cleaved by triphenylphosphane to afford the mononuclear [Pt(C9H6NCO-kappa N,kappa C)(COMe)(PPh3)] (5) with the two acyl groups in cis positions. The reaction of the diacetylbis(amine)platinum(II) complexes [Pt(COMe)(2)(NH2R)(2)] (R = CH2Ph (2a), Et (2b)) with quinoline-8-carbaldehyde produced the Schiff base products [Pt(COMe)(2)(C9H6NCH=NR-kappa N,kappa N')] (R = CH2Ph (6a), Et (6b)). The complexes have been fully characterized, and X-ray diffraction structures of 3 and 4 are reported.