Hypoxia activated Co(III) complexes as prodrugs may provide with a selective delivery of cytotoxic or antibacterial compounds. Whithin this field sixteen novel Co(III) ternary complexes with the ...general formula Co(4N)(flav)(ClO4)2, where 4N = tris(2-aminoethyl)amine (tren) or tris(2-pyridylmethyl)amine (tpa) and flav = deprotonated form of differently substituted flavonols have been synthesized, characterized, and their cytotoxicity assayed under both normoxic and hypoxic conditions. Molecular structures of two free flavonols and seven complexes are also reported. In all the complexes the bioligands exhibited the expected (O,O) coordination mode and the complexes showed a slightly distorted octahedral geometry. Cyclic voltammetric studies revealed that both the substituents of the flavonoles and the type of 4N donor ligands had an impact on the reduction potential of the complex. The ones containing tren demonstrated significantly higher stability than the tpa analogues, making these former compounds promising candidates for the development of hypoxia-activated prodrug complexes. Tpa complexes showed higher activity against both selected human cancer cell lines (A549, A431) than their free ligand flavonols, indicating that the anticancer activity of the bioligand can be enhanced upon complexation. However, slight hypoxia-selectivity was found only for a tren complex (11) with moderate cytotoxicity.
Novel, multitargeted Co(III) complexes with flavonolate and ancillary 4N donor ligands have been synthesized, characterized and tested against selected human derived cancer cell lines under hypoxic and normoxic conditions. Display omitted
•Synthesis of CoIII(4N)(flavonolato)2+ type complexes with flavonoles as bioligands.•Chemical characterization of the novel complexes including X-ray studies.•Dependence of the redox behavior of the complexes on the tripodal tetramine (4N).•Biological assay of the complexes against A549 and A431 cancer cell lines.
Buchwald-Hartwig Reactions of Monohaloflavones Kónya, Krisztina; Pajtás, Dávid; Kiss-Szikszai, Attila ...
European journal of organic chemistry,
February 2015, Letnik:
2015, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The article describes the amination of different monobromo‐ or monochloroflavones with primary and secondary alkylamines and aniline derivatives by Buchwald–Hartwig reaction. The influence of the ...phosphine ligands used is described. The use of amino acid derivatives as a nitrogen source is also demonstrated. This latter reaction allows the synthesis of unique flavone–amino‐acid conjugates.
A new and efficient approach to (substituted) aminoflavones and hybrids of flavones and amino acids using Buchwald–Hartwig coupling was developed and optimised.
The palladium-catalyzed Suzuki–Miyaura coupling reaction of tetrabromo-p-benzoquinone and 2,3-dibromonaphthoquinone provide a convenient approach to tetraaryl-p-benzoquinones and ...2,3-diarylnaphthoquinones. Suzuki–Miyaura of tetrabromo-1,4-phenylene bis(trifluoromethanesulfonate) and of 2,3-dibromonaphthalene-1,4-diyl bis(trifluoromethanesulfonate) resulted in the formation of the same type of quinone products instead of the expected benzene and naphthalene derivatives.
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Mono‐, di‐, and tetraalkynylated selenophenes were prepared by site‐selective Sonogashira reactions of tetrabromoselenophene. Aryl‐, alkyl‐, and trimethylsilylacetylenes were suitable substrates for ...this procedure. The first attack occurred regioselectively at C‐2 and C‐5. In addition, differently diarylated dialkynylselenophenes were prepared using site‐selective Suzuki and Sonogashira reactions.
Mono‐, di‐, and tetraalkynylated selenophenes can be ontained by site‐selective Sonogashira reactions of tetrabromoselenophene. Aryl‐, alkyl‐, and trimethylsilylacetylenes are suitable starting materials. Differently diarylated dialkynylselenophenes can be synthesized by site‐selective Suzuki and Sonogashira reactions.
The Suzuki–Miyaura reaction of 2,6-dichloro-3-(trifluoromethyl)pyridine with 1equiv of arylboronic acids resulted in site-selective formation of 2-aryl-6-chloro-3-(trifluoromethyl)pyridine. Due to ...electronic reasons, the reaction takes place at the sterically more hindered position. The one-pot reaction with two different arylboronic acids afforded 2,6-diaryl-3-(trifluoromethyl)pyridine containing two different aryl substituents. The reactions proceeded smoothly in the absence of phosphane ligands.
Arylated anthraquinones were prepared by Suzuki–Miyaura reactions of the bis(triflates) of various 1,3-(dihydroxy)anthraquinones. While the reactions of the bis(triflates) of parent ...1,3-(dihydroxy)anthraquinone and of 2-chloro-1,3-di(hydroxy)anthraquinone proceeded with very good site-selectivity, the corresponding reactions of the bis(triflate) of 2-fluoro-1,3-diarylanthraquinones were not site-selective, which was explained based on the π-donating effect of the fluorine atom.
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Suzuki–Miyaura reactions of 2,6-dichlorobenzoxazole provide a convenient access to arylated benzoxazoles. The reactions proceed with excellent site-selectivity in favour of position 2, due to ...electronic reasons.
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Arylated coumarins were prepared by site-selective Suzuki–Miyaura cross-coupling reaction of the bis(triflate) of 4,7-dihydroxycoumarin. The reactions proceeded by initial attack to the sterically ...more hindered position, due to electronic reasons.
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