Journal of Sulfur Chemistry最新文献

In this study, the solvent effects are probed on the chemical reaction of the (E)-3-thiophene-2-yl-indoline-2-thione (I) and [20] fullerene, and the resulted complex (I_a) via the density functional theory (DFT). To characterize the synchronicity of the reaction and its correlation with activation energy, we estimated the energy barrier of transition states (E_TS1^≠ and E_TS2^≠) in the used solvents. The highest E_TS1^≠ and E_TS2^≠ value are found in water solvent, whereas the lowest E_TS1^≠ and E_TS2^≠ value are considered in the gas phase. Formation of the TS2 appears energetically less favorable due to the non-bonding electrostatic repulsion among the sulfur heteroatoms and C₂₀, also the π–stacking between the thiophene ring and nanocage, which affects the stability of the TSs. The most thermodynamic stability, the adsorption energy difference among liquid phase and gas phase (ΔE_l-g = E_l − E_g), and the most polarity (µ) belongs to stabilizing effect of water solvent on I_a, whereas the lowest thermodynamic stability, the lowest released ΔE_l-g and the least polarity belongs to optimization of I_a in the gas phase. This stabilizing effect is attributed to the possibility of hydrogen bonding and dipole–dipole interaction in the water. The n→π* donation of N–C═S leads to a stronger interaction between sulfur heteroatom of I and fullerene. In contrast to the previous report on the produced thio-oxindoles in organic solvents, toluene was found to be the best solvent in terms of the highest yield and the shortest reaction time, in this case, adsorption takes place in water with no catalyst addition.

Here, we have focused on chemical reaction of I and C₂₀ to produce I_a complex via the optimized TSs in the gas phase, toluene, dichloromethane, methanol, acetonitrile, dimethyl sulfoxide and water, using DFT approach.

This review provides comprehensive data on the recent advances in various preparative methods of carbamides/thiocarbamides possessing oxygen/sulfur donor sites and their biological relevance. This review summarizes the numerous protocols for synthesizing carbamides/thiocarbamides from isocyanides, amidines, or amines, carbamates, alkyl halides are described, and also their green synthesis thus considerably expanding the scope of carbamides/thiocarbamides chemistry. Due to its tunable physicochemical and structural features, carbamide/thiocarbamide-based scaffolds are widely used in medicinal chemistry. Nowadays, protein kinase inhibitors are the topic of interest for several drug development initiatives in the pharmaceutical industry, because genetic changes such as mutations, overexpression, translocations, and dysregulation are all involved in the pathogenesis of many disorders. In this review, the compounds comprising carbamide/thiocarbamide pharmacophore have significant efficacy in comparison with the typical antibiotics against many bacterial strains which cause nosocomial infections and have acquired resistance to numerous medicines in the treatment of bacterial infections as well as a variety of ageing-related health issues such as cancer, antioxidants to inhibit uncontrolled growth of cells in the biological system, antifungal agents to inhibit the fungus growth, and neurological dysfunction have been described.

A novel [C₄H₁₀-DABCO][ClO₄]₂ DABCO based protic acid supported ionic liquid has been synthesized, characterized, and evaluated as an efficient, economic, and reusable catalyst for the one pot, three component synthesis of 1,3-thiazolidin-4-one in an aqueous medium with high to excellent yield. This study compares DABCO based ionic liquids [H₂-DABCO][HSO₄]₂, [H₂-DABCO][H₂PO₄]₂, [H₂-DABCO][ClO₄]₂, and [C₄H₁₀-DABCO][ClO₄]₂ to highlight the impact of cations and anions on the catalytic applicability and moisture-resistance properties. The DABCO based Bifunctional Acidic Ionic Liquid (DBAIL) catalyst was effectively recycled five times without losing significant catalytic activity. Five of the synthesized derivatives were evaluated for their cytotoxic activity against the MCF-7 cell line using MTT assay, and the compounds showed moderate to good activity.

This study reports the existence of redox-induced electron transfer in lithium polysulfides (RIET). The presence of redox-induced electron transfer in lithium polysulfides is confirmed using a DFT study. The sulfur gets oxidized, and lithium gets reduced during the removal of an electron from lithium polysulfides. The condensed Fukui function from Natural Population Analysis (NPA) charge and electron density augment RIET. The higher number of sulfur contributes to the total nucleophilic character of lithium polysulfide and holds lithium tightly. The presence of an electric field enhances the nucleophilicity of sulfur atoms and, hence, the reactivity of lithium polysulfides.

In this article, six new Fe₃S₂ cluster complexes Fe₃(µ₃S)₂(CO)₇[(Ph₂P)₂NR] (1-6) (R = (CH₂)₂CH₃, CH(CH₃)₂, (CH₂)₃CH₃, CH₂CH(CH₃)₂, p-C₆H₄CCH and m-C₆H₄CCH) were successfully synthesized by reactions of Fe₃S₂(CO)₉ and the corresponding aminodiphosphines under refluxing toluene. Meanwhile, treatment of Fe₃S₂(CO)₉ and (Ph₂P)₂NCH(CH₃)Ph afforded two new Fe₃S₂ cluster complexes Fe₃(µ₃-S)₂(CO)₇[(Ph₂P)₂NCH(CH₃)Ph] (7) and Fe₃(µ₃-S)₂(CO)₇[(κ²-Ph₂P)₂NCH(CH₃)(Ph)] (8). Complexes 1–8 were characterized by elemental analysis, FT-IR, NMR spectroscopy, and especially X-ray crystallography. The elctrochemical properties were investigated by cyclic voltammetry, showing that they all have electrocatalytic ability for the reduction of protons to H₂.

Mitigation of the activity of the main protease (M^pro) and papain-like protease (PL^pro) of SARS CoV-2 has direct implications in combating the ongoing deadly COVID-19 pandemic. The active site of these proteases contains cysteine thiols which are covalently modified by the sulfur drugs such as ebselen and disulfiram. The natural product of Allium contains several reactive sulfur compounds that may covalently modify the active site cysteine thiols of coronavirus proteases. The report has assessed the binding affinity of the 52 different sulfur compounds of Allium against both M^pro and PL^pro of coronavirus by conventional docking methods. Three of the top six compounds have demonstrated high affinity for both the proteases, namely, E-ajoene (S3), S-(3-pentanyl)-L-cysteine-sulfoxide (S49), and 1-propenyl allyl thiosulfinate (S14). The reactive sulfur compounds E-ajoene and 1-propenyl allyl thiosulfinate were subjected to the calculation of energetics of the putative reactions and covalent docking studies. The results indicate they covalently modify the active site cysteine thiols of the proteases through S-thioallylation, S-thioallyl sulfinyl propenylation, and S-thiopropenylation. The diversity of covalent modifications, high affinity for both the proteases and sulfur-mediated hydrogen bonds at the active site indicate that E-ajoene is a potential dual protease targeting covalent inhibitor of SARS CoV-2.

The protonation of thioanisols by strong acids, such as trifluoroacetic acid or trifluoromethane sulfonic acid was investigated by ¹H NMR spectroscopy, including experiments with deuterated acids. Contrary to reported literature and to general expectations, protonation of thioanisole does not occur exclusively at the methylmercapto group but also to a lower extent at the aromatic ring. In cases of methoxy-substituted thioanisols protonation can take place at both heteroatomic groups and at the aromatic ring. The sites of protonation depend on the substituent pattern as unambiguously indicated by deuteration.

Two 2D Zn(II) coordination polymers, formulated as [Zn(μ₂-tdc)(μ-pmid)] (1), {[Zn(μ₂-tdc)(μ-pmmid)₂·4H₂O]}_n (2) (H₂tdc = 2,5-thiophenedicarboxylic acid, pmid = 1-(4-pyridylmethyl)imidazole; pmmid = 1-(4-pyridylmethyl)-2-methylimidazole) have been synthesized by reactions of Zn(OAc)₂·2H₂O and H₂tdc with flexibleN-(4-pyridylmethyl)imidazole derivatives under the mild reaction conditions and characterized by single-crystal X-ray diffraction and other physicochemical methods. Structure determination demonstrates compound 1 displays a 2-fold 2D → 2D parallel interpenetrating structure, while compound 2 shows a 2D non-interpenetrating network. These results reveal that the substitute group in such N-(4-pyridylmethyl)imidazole derivatives might be the main factor resulting in these interpenetrating/ non-interpenetrating structures.Furthermore, compounds 1 and 2 show different thermal stabilities and strong solid-state luminescence emissions.

The nanocomposites have an important role in accelerating the adsorption of sulfur compounds because of their improved chemical and mechanical characteristics. In this study, silver nanoparticles, zinc oxide nanoparticles, and silver/zinc oxide nanoparticles were greenly synthesized and loaded with activated carbon by a successive precipitation method for the adsorptive desulfurization of model oil (dibenzothiophene, DBT, in 85% hexane + 15% toluene). The obtained adsorbents were characterized by using UV-visible spectroscopy, Fourier transmission infrared spectroscopy, a field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller surface area (S_BET) analysis to confirm their structure, chemical composition, functional groups present on the adsorbents, and surface area. The adsorption experiments were conducted under optimal conditions, with 0.15 g of adsorbent dosage and a contact time of 1 h at 25 °C, during which the (Ag/ZnONPS-AC) adsorbent removed 99% of dibenzothiophene (250 mg/l). The total order removal performance of DBT of: Ag/ZnONPS-AC > ZnONPS-AC > AgNPS-AC > AC was observed. Kinetic studies revealed that the adsorption process of (Ag/ZnONPS-AC) obeyed pseudo-second-order kinetics and the Langmuir adsorption isotherm model. This study provides a cost-effective adsorbent for the effective desulfurization of model oil.

Herein, we reported an effectual protocol for the stereoselective synthesis of novel C-3 thio/seleno substituted ortho-, meta- and para-(2-benzo[d]oxazolyl)phenyl-β-lactams 7a-i. The reaction was performed by utilizing different S/Se-alkyl/aryl substituted acids 6a-d and isomeric ortho-, meta- and para-(2-benzo[d]oxazolyl)phenyl Schiff’s bases 3a-c and afforded exclusive formation of trans-β-lactams. The trans configuration was assigned with respect to coupling constant values of C3-H and C4-H (J = 1.4 to 2.6; C3-H and C4-H). The structure elucidation of all the thio/seleno anchored β-lactams 7a-i was performed using various spectroscopic techniques viz. FT-IR, NMR (¹H, ¹³C, and ¹³C DEPT–135), 2D-NMR (¹H–¹H COSY and ¹H–¹³C HSQC), elemental analysis (CHN), and mass spectrometry (ESI-MS). Further, divergent substrate scope accompanied by plausible mechanistic investigation have been also described. Stereoselectivity, good functional group tolerance and excellent yield along with wider synthetic utility bestows advantages to the present protocol.