5346-38-3Relevant articles and documents
New multidentate ligands for supramolecular coordination chemistry: Double and triple helical complexes of ligands containing pyridyl and thiazolyl donor units
Rice, Craig R.,Woerl, Stefan,Jeffery, John C.,Paul, Rowena L.,Ward, Michael D.
, p. 550 - 559 (2001)
Four new multidentate N-donor ligands L1-L4 have been prepared which contain a combination of pyridyl and thiazolyl donor units. The syntheses of these ligands are facile and high-yielding, being based on reaction of an α-bromoacetyl unit with a thioamide to form the thiazolyl ring. The extended linear sequence of ortho-linked N-donor heterocycles (four for L1, six for L2; five for L3; and six for L4) is reminiscent of the well-known linear oligopyridines, although these new ligands are much easier to make and have significantly different geometric coordination properties because the presence of the five-membered thiazolyl rings results in natural breaks of the ligand backbone into distinct bidentate or terdentate domains. Thus, the tetradentate ligand L1 partitions into two bidentate domains to give dinuclear triple helicates [M2(L1)3]4+ with six-coordinate first-row transition metal dications (M = Co, Cu, Zn). The hexadentate ligand L2 partitions into two terdentate domains to give dinuclear double helicates [M2(L2)2]4+ with six-coordinate metal ions (M = Cu, Zn). In the double helicate [Cu2(L3)2]4+ the pentadentate ligand L3 only uses its two terminal bidentate binding sites, resulting in four-coordinate Cu(II) centres and a non-coordinated pyridyl residue in the centre of each of the two ligand strands. These pendant pyridyl residues are directed towards each other to give a potentially two-coordinate cavity between the metal ions in the centre of the helicate. Similarly, in the double helicate [Cu2(L4)2]4+ the metal ions are only four-coordinate, with each ligand having its central bipyridyl unit un-coordinated. This results in a potentially four-coordinate cavity between the two metal ions in the centre of the helicate. These easy-to-prepare ligands offer a great deal of scope for the development of multinuclear helicates.
Aerobic Visible-Light Induced Intermolecular S?N Bond Construction: Synthesis of 1,2,4-Thiadiazoles from Thioamides under Photosensitizer-Free Conditions
Wang, Hui,Xie, Shihua,Zhu, Hongjun,Zhuo, Liang
supporting information, p. 3398 - 3402 (2021/06/25)
Aerobic visible-light induced intermolecular S?N bond construction has been achieved without the addition of photosensitizer, metal, or base. With this strategy, 1,2,4-thiadiazoles can be obtained from thioamides. Preliminary mechanistic investigation suggested that the excited state of thioamides undergoes a single-electron-transfer (SET) process to afford thioamidyl radicals, which can be further transformed into a 1,2,4-thiadiazole through desulfurization and oxidative cyclization. The reaction has good functional group tolerance and represents a green method for the construction of S?N bonds.
Potent ribonucleotide reductase inhibitors: Thiazole-containing thiosemicarbazone derivatives
Ertas, Merve,Sahin, Zafer,Bulbul, Emre F.,Bender, Ceysu,Biltekin, Sevde N.,Berk, Barkin,Yurttas, Leyla,Nalbur, Aysu M.,Celik, Hayati,Demirayak, ?eref
, (2019/11/03)
The antioxidant, antimalarial, antibacterial, and antitumor activities of thiosemicarbazones have made this class of compounds important for medicinal chemists. In addition, thiosemicarbazones are among the most potent and well-known ribonucleotide reductase inhibitors. In this study, 24 new thiosemicarbazone derivatives were synthesized, and the structures and purity of the compounds were determined by IR, 1H NMR, 13C NMR, mass spectroscopy, and elemental analysis. The IC50 values of these 24 compounds were determined with an assay for ribonucleotide reductase inhibition. Compounds 19, 20, and 24 inhibited ribonucleotide reductase enzyme activity at a higher level than metisazone as standard. The cytotoxic effects of these compounds were measured on the MCF7 (human breast adenocarcinoma) and HEK293 (human embryonic kidney) cell lines. Similarly, compounds 19, 20, and 24 had a selective effect on the MCF7 and HEK293 cell lines, killing more cancer cells than cisplatin as standard. The compounds (especially 19, 20, and 24 as the most active ones) were then subjected to docking experiments to identify the probable interactions between the ligands and the enzyme active site. The complex formation was shown qualitatively. The ADME (absorption, distribution, metabolism, and excretion) properties of the compounds were analyzed using in-silico techniques.
