Oxidation of the Platinum(II) Anticancer Agent [Pt{(<i<p</i<-BrC<sub<6</sub<F<sub<4</sub<)NCH<sub<2</sub<CH<sub<2</sub<NEt<sub<2</sub<}Cl(py)] to Platinum(IV) Complexes by Hydrogen Peroxide

Pt<sup<IV</sup< coordination complexes are of interest as prodrugs of Pt<sup<II</sup< anticancer agents, as they can avoid deactivation pathways owing to their inert nature. Here, we report the oxidation of the antitumor agent [Pt<sup<II</sup<(<i<p</i<...
Ausführliche Beschreibung

Pt<sup<IV</sup< coordination complexes are of interest as prodrugs of Pt<sup<II</sup< anticancer agents, as they can avoid deactivation pathways owing to their inert nature. Here, we report the oxidation of the antitumor agent [Pt<sup<II</sup<(<i<p</i<-BrC<sub<6</sub<F<sub<4</sub<)NCH<sub<2</sub<CH<sub<2</sub<NEt<sub<2</sub<}Cl(py)], <b<1</b< (py = pyridine) to dihydroxidoplatinum(IV) solvate complexes [Pt<sup<IV</sup<{(<i<p</i<-BrC<sub<6</sub<F<sub<4</sub<)NCH<sub<2</sub<CH<sub<2</sub<NEt<sub<2</sub<}Cl(OH)<sub<2</sub<(py)].H<sub<2</sub<O, <b<2·H<sub<2</sub<O</b< with hydrogen peroxide (H<sub<2</sub<O<sub<2</sub<) at room temperature. To optimize the yield, <b<1</b< was oxidized in the presence of added lithium chloride with H<sub<2</sub<O<sub<2</sub< in a 1:2 ratio of Pt: H<sub<2</sub<O<sub<2,</sub< in CH<sub<2</sub<Cl<sub<2</sub< producing complex <b<2·H<sub<2</sub<O</b< in higher yields in both gold and red forms. Despite the color difference, red and yellow <b<2·H<sub<2</sub<O</b< have the same structure as determined by single-crystal and X-ray powder diffraction, namely, an octahedral ligand array with a chelating organoamide, pyridine and chloride ligands in the equatorial plane, and axial hydroxido ligands. When tetrabutylammonium chloride was used as a chloride source, in CH<sub<2</sub<Cl<sub<2</sub<, another solvate, [Pt<sup<IV</sup<{(<i<p</i<-BrC<sub<6</sub<F<sub<4</sub<)NCH<sub<2</sub<CH<sub<2</sub<NEt<sub<2</sub<}Cl(OH)<sub<2</sub<(py)].0.5CH<sub<2</sub<Cl<sub<2,</sub<<b<3·0.5CH<sub<2</sub<Cl<sub<2</sub<</b<, was obtained. These Pt<sup<IV</sup< compounds show reductive dehydration into Pt<sup<II</sup< [Pt{(<i<p</i<-BrC<sub<6</sub<F<sub<4</sub<)NCH=CHNEt<sub<2</sub<}Cl(py)], <b<1H</b< over time in the solid state, as determined by X-ray powder diffraction, and in solution, as determined by <sup<1</sup<H and <sup<19</sup<F NMR spectroscopy and mass spectrometry. <b<1H</b< contains an oxidized coordinating ligand and was previously obtained by oxidation of <b<1</b< under more vigorous conditions. Experimental data suggest that oxidation of the ligand is favored in the presence of excess H<sub<2</sub<O<sub<2</sub< and elevated temperatures. In contrast, a smaller amount (1Pt:2H<sub<2</sub<O<sub<2</sub<) of H<sub<2</sub<O<sub<2</sub< at room temperature favors the oxidation of the metal and yields platinum(IV) complexes. Ausführliche Beschreibung

Autor*in:	Ruchika Ojha [verfasserIn] Peter C. Junk [verfasserIn] Alan M. Bond [verfasserIn] Glen B. Deacon [verfasserIn]

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2023

Schlagwörter:	platinum anticancer agents platinum(II) complexes platinum(IV) complexes hydrogen peroxide oxidation of platinum(II) complexes

Übergeordnetes Werk:	In: Molecules - MDPI AG, 2003, 28(2023), 17, p 6402
Übergeordnetes Werk:	volume:28 ; year:2023 ; number:17, p 6402

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DOI / URN:	10.3390/molecules28176402

Katalog-ID:	DOAJ09349789X