The synthesis and characterization of N-substituted iminodiacetato cis-, trans-R, R- and trans-S, S-1, 2-diaminocyclohexane platinum(II) complexes: steric effects on the diastereomeric ratios.
A series of platinum(II) complexes of the type [Pt(N-R-IDA)(DACH)], where DACH was either cis-1,2-diaminocyclohexane, trans-R, R-1, 2-diaminocyclohexane, or trans-S, S-1, 2-diaminocyclohexane, and N-R-IDA was either the iminodiacetate, N-methyliminodiacetate, N-n-propyliminodiacetate, or N-t-butyliminodiacetate ion, has been prepared and characterized. A detailed NMR investigation shows that the N-R-IDA ions bind to the platinum (II) ion through one of the acetate oxygens and the imino nitrogen, forming a five-membered ring. The second acetate ion does not bind to the platinum. By virtue of the prochiral N-atom of N-R-IDA and the absence of a horizontal plane of symmetry of the Pt(DACH) moiety, two diastereomers are observed corresponding to the two different orientations of the unbound acetate and the R-group with respect to the platinum coordination plane. The ratio of the two geometric isomers is controlled by steric factors depending upon both the isomeric form of 1,2-diaminocyclohexane and the nature of the R group bound to the imino nitrogen of N-R-IDA.
Khokhar
A R
AR
Department of Medical Oncology, University of Texas, M.D. Anderson Cancer Center, Houston 77030.
Lumetta
G J
GJ
Bear
J L
JL
D000970:Antineoplastic Agents; D055598:Chemical Phenomena; D002621:Chemistry; D009682:Magnetic Resonance Spectroscopy; D009944:Organoplatinum Compounds / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds