Journal of Sulfur Chemistry最新文献

Benzothiadiazine 1,1-dioxide derivatives are widely used because of their diverse biological activities and medicinal prospects. In this study, iodine-oxone mediated oxidative N–S bond formation reaction was described. This new and transition-metal-free approach allows for the convenient synthesis of a variety of 1,2,4-benzothiadiazine 1,1-dioxides from readily available urea derivatives under very mild conditions without using expensive reagents and catalysts. Further, this protocol allows for the development of a library of key building blocks with potential medical applications.

A green and sustainable chemistry approach for organic synthesis is described here, which involves microwave exposure of reactants in the presence of water. A general, practical, and highly efficient protocol for the preparation of a broad range of functionalized isothiocyanates has been developed from their corresponding isocyanides using Lawesson's reagent and catalytic amount of amine bases, particularly triethylamine under microwave irradiation conditions. As opposed to established approaches that employ toxic or volatile electrophilic liquids (thiophosgene, its derivatives, or CS₂). In addition, these compounds were synthesized also by conventional heating procedures for comparison. Comparison between conventional and microwave-assisted synthesis was carried out by comparing total reaction time and percentage yield. The results suggest that microwave-assisted syntheses lead to higher yields within very short reaction times.

From isocyanides to isothiocyanates using Lawesson’s reagent in the presence of triethylamine under conventional and microwave heating conditions.

High-level ab initio and density functional theory were applied to investigate property and reactivity of polyselenides and polysulfides. With CH₃X_nH (X = S or Se) we found that the deprotonation energy (and pK_a) of CH₃Se_nH, ionization potential (IP) of, and CH₃Se_n−H bond dissociation energy (BDE) are lower than those of their sulfur counterparts. For n = 2, IPs and X−H BDEs are exceptionally small. The relative nucleophilicity of $\text{C}{\text{H}}_3{\text{X}}_n^{-}$ vary with substrates. However, CH₃Se_nH are more nucleophilic than CH₃S_nH due to their due to their lower deprotonation energy. The nucleophilicity of selenolates versus thiolates are related to the chemical nature. Selenium is more electrophilic than sulfur.

Substituted thiocarbohydrazones were synthesized to study their complexation capability towards Cu(I), Co(II), and Ni(II) salts. The Cu(I) complexes showed ligation of one mole of Cu(I)Br to one of the synthesized ligands to form a cationic–anionic metal complex. Co(II) and Ni(II) complexes were determined due to the chelating of equal equivalents of both ligands and metal salts to form monodentate metal dihalogenated complexes. Metal complexes were characterized by mass spectrometry, IR, NMR, UV spectra, and elemental analyses. Theoretical calculations were performed using density functional theory (DFT) at the B3LYP level with 6–31 + G(d) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the HOMO (highest occupied molecular orbital), the LUMO (lowest unoccupied molecular orbital), the molecular electrostatic potential (MEP), reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), and chemical potential. The calculations confirmed that the investigated complexes have a reliable geometry, agreeing with the experimental observation.

Ferrocene and its derivatives compounds have shown a significant role in medicinal organometallic chemistry as an antiparasitic or antibacterial. Therefore, we herein report on the utilization of dithioesters ferrocenyl derivatives as proligands for the synthesis of heteroleptic platinum(II) and homoleptic palladium(II) complexes bearing a conserved O,S binding moiety. The resulting complexes [Pt(L1)(DMSO)Cl] (1), [Pt(L2)(DMSO)Cl] (2), [Pt(L3)(DMSO)Cl] (3), [Pd(L1)₂] (4), [Pd(L2)₂] (5), and [Pd(L3)₂] (6), in which HL1 = methyl 3-hydroxy-3-ferroceneprop-2-enedithioate, HL2 = ethyl 3-hydroxy-3-ferroceneprop-2-enedithioate and HL3 = propyl 3-hydroxy-3-ferroceneprop-2-enedithioate, were fully characterized employing a variety of analytical techniques (NMR spectroscopy, elemental analysis, and mass spectrometry and X-ray structure determination of complexes 2 and 6). Cytotoxicity assays of the synthesized ligands as well as the Pt/Pd metal complexes showed low toxicity towards ovarian cancer cells, but the compounds are not affected by cisplatin resistance mechanisms. Pt(II) complexes exhibited the highest activity, and the alkyl substituent strongly influenced the activity of these complexes and the free ligands. The cytotoxic activity increases with the length of the alkyl chain with 3 exhibiting a mean IC₅₀ of 56 µM.

Novel dihydropyrimidines incorporating an adamantane motif have been synthesized using a three-component Biginelli reaction of adamantane-containing β-keto amide N-1-adamantyl acetoacetamide as active methylene compound, thiourea, and aromatic aldehydes in more convenient condition and high yields. The structures of the synthesized compounds were confirmed by spectral data.