Phosphorus, Sulfur, and Silicon and the Related Elements最新文献

We developed and synthesized novel 4-thiazolidinone hybrids with pyridine and pyrazole heterocycles (5a-5o). The structures of the synthesized products were elucidated by IR, ¹H NMR and ¹³C NMR spectroscopy and mass spectrometry. The synthesized hybrids were investigated for their antimicrobial activity against several bacterial and fungal strains using the Mueller–Hinton broth method. Compound 5-(3-methoxybenzylidene)-2-(1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl)-3-(pyridin-3-yl)thiazolidin-4-one (MIC = 50 μg/mL) exhibited prominent activity against gram-negative E. coli while compounds 5-(2-methylbenzylidene)-2-(1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl)-3-(pyridin-3-yl)thiazolidin-4-one and 5-(4-methylbenzylidene)-2-(1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl)-3-(pyridin-3-yl)thiazolidin-4-one exhibited MIC value of 250 μg/mL against C. albicans. Molecular docking study against microbial DNA gyrase could provide valuable insights into the binding modes of these molecules. They were found to exhibit excellent binding affinity (average Glide docking score: −7.989 and binding energy: −49.807 kcal/mol) through significant bonded and non-bonded interactions.

The reactivity of the nacnac Cu(I) compound [L²Cu(MeCN)] (2) (L² = [{N(C₆H₃Me₂-2,6)C(Me)}₂CH]^-) towards complexes containing aromatic cyclo-E₅ ligands (E = P, As) was investigated. The copper complex was reacted with [Cp*Ru(η⁵-E₅)] (E = P (1a-Ru), As (1b-Ru)), yielding the heterometallic complexes [(Cp*Ru)(μ,η^5:2-E₅)(L²Cu)] (E = P (3a), As (3b)). These neutral and molecular complexes represent rare examples of the coordination of group 11 metal complexes to cyclo-E_n units and are also rare examples of the coordination compounds of 1a-Ru and 1b-Ru. They were fully characterized by crystallographic and spectroscopic methods and compared to related compounds.

A preparatively convenient one-pot method for the synthesis of new 7-thioxo[1,3]thiazolo[3,2-c]pyrimidine derivatives 3a–3l by the cyclocondensation of 5-methyl(1,3-thiazolidin-2-ylidene)ketones 1a–1c with aroyl 2a–2d and 2-thienyl 2e isothiocyanates for 6–10 h boiling in acetone has been developed. Studies of the antimicrobial and antioxidant activities potential of the obtained compounds revealed that [2-methyl-5-(4-nitrophenyl)-7-thioxo-2,3-dihydro-7H-[1,3]thiazolo[3,2-c]pyrimidine-8-yl](phenyl)methanone 3k, effect on the test culture of M. luteum at a concentration of 0.5% is close to the control drug vancomycin. Moreover, [5-(4-bromophenyl)-2-methyl-7-thioxo-2,3-dihydro-7H-[1,3]thiazolo[3,2-c]pyrimidin-8-yl](phenyl)methanone 3j has an antibacterial effect on the specified test culture at a minimum inhibitory concentration of 15.6 μg/mL. In turn, 1-(2-methyl-5-(thiophen-2-yl)-7-thioxo-2,3-dihydro-7H-[1,3]thiazolo[3,2-c]pyrimidin-8-yl]ethanone 3d can be considered promising for further structural modification to enhance the antioxidant effect. The structure of all synthesized substances was established by spectral analysis (¹H and ¹³C NMR, LC–MS, and FT-IR). Additionally, the structure of compound 3i was confirmed by X-ray diffraction analysis.

Phosphate glasses are characterized by properties distinguished by comparison with those of others such as borates, silicates, and tellurides that can be used in many fields such as optics, electronics, medicine, environmental protection, etc. This study aims to discover the effect of the europium dopant on the structural properties of glasses with 65% P₂O₅ – (35-x) % SrO – x% Eu₃O₂ (where x = 0.5, 1, 1.5, 2 mol at. %) using molecular dynamics simulations. The density of simulated glasses was found to increase from 2.784 to 2.860 g/cm³ according to the gradual increase in the europium content. The Eu-O distances and coordination numbers are found to be in the ranges of 2.18–2.21 Å and 6.59–6.79, respectively. The Sr-O coordination numbers were found to decrease from 7.30 to 6.55 with an increase in the europium content in the phosphate glasses. The coordination of the Eu-Eu pair increases from 0.07 to 0.23 with increasing europium concentration in phosphate glasses, but it remains weak, which is a sign of good solubility of europium in the glass matrix, as expected by experiments and the literature. Studies of the cluster statistics in the simulated glasses demonstrate that most europium atoms are found isolated or in a doublet.

The regioselectivity of halogenation of terminal and internal thioethers of 7-(trifluoromethyl)quinazolin-4(3H)-ones was investigated. It is proven that the direction of halocyclization of allyl thioethers depends on the presence of a substituent at the terminal carbon atom of the allyl moiety. The cyclization of allyl, methallyl and prenyl thioethers leads to the annulation of thiazole cycle with the formation of thiazolo[3,2-a]quinazolinium trihalides while cyclization of cinnamyl thioether forms thiazino[3,2-a]quinazolinium trihalides with the additional thiazine cycle.

A simple and green method was developed for the reaction of 2-aminothiophenol and benzaldehyde in the self-neutralizing acidic CO₂-alcohol system to produce benzothiazoles. A series of benzothiazole derivatives were successfully prepared from the condensation and cyclization reaction of 2-aminothiophenol or substituted 2-aminothiophenol with aliphatic, heteroaryl and aryl aldehydes promoted by alkyl carbonic acid under mild conditions. Moreover, the method is also suitable for the synthesis of 2-phenylbenzimidazole and 2-phenylbenzoxazole. Additionally, this reaction system greatly simplified post-processing, which did not need to be neutralized with base and without salt disposal. These advantages make the process more practical, economical, and environmentally friendly. Mechanism investigation indicated that formation of alkyl carbonic acid from CO₂ and methanol is the key intermediate, which provides hydrogen ions to catalyze the reaction of 2-aminothiophenol and benzaldehyde.

In this article, we show that tribromide heterogenized on the surface of silica-coated magnetic nanoparticles modified with N²,N4,N⁶-tris(aminomethyl)-1,3,5-triazine-2,4,6-triamine [Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃] is a novel and efficient reusable nanocatalyst for the oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides using hydrogen peroxide as green oxidant. The structure of the as-fabricated Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃ was characterized by a series of spectroscopic techniques including FT-IR spectroscopy, SEM, TEM, EDX, VSM, XRD and TGA techniques. TEM and SEM analysis confirmed that the typical silica shell thickness was assessed to be around 20 nm. Recycling studies revealed that the Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃ could be easily recovered by a simple magnetic separation and recycled at least 6 times without deterioration in catalytic activity.

In order to obtain a flame-retardant epoxy resin (EP) composite with good flame retardancy, ammonium polyphosphate (APP) was applied to EP in combination with hexa-(4-(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide)-hydroxymethylphenoxy)cyclotriphosphazene (HAP-DOPS). The experimental results showed that the flame retardancy of EP composite can be improved effectively when HAP-DOPS was compounded with APP and added to EP. Under the premise condition of the phosphorus content in the system was 1.6% and m _HAP-DOPS: m _APP = 1.5:1, the LOI value reached 30.0% and the vertical burning test reached UL94 V-0 rating, at which point the flame retardancy of the compound system was optimal. Compared with HAP-DOPS/EP, the thermal stability of HAP-DOPS/APP/EP was improved, and the char residues were increased; the total heat release (THR) was decreased by 40.66%, and the total smoke release (TSR) was decreased by 34.13%. And the flexural strength and tensile strength were increased by 32.52% and 14.46%, respectively. The study of flame-retardant mechanism showed that the addition of HAP-DOPS/APP to EP can promote the formation of phosphorus-rich char residues, which mainly played a flame-retardant role in the condensed phase and in the gaseous phase by releasing noncombustible NH₃.

The possibilities for the preparation of dialky phenylphosphonates were evaluated. On the one hand, the oxidation of phenyl-H-phosphinates gave the corresponding phenylphosphonic acid monoesters. On the other hand, phenylphosphonates may be prepared by MW-assisted direct esterification of phenylphosphonic acid. The reaction with alcohols was performed under MW irradiation in the presence of an ionic liquid as the catalyst. The second ester function was established by alkylating esterification carried out with alkyl halides in the presence of triethylamine under MW conditions.

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The direct synthesis of organophosphorus compounds from white phosphorus (P₄) has very important scientific significance and application value. The review focuses on the direct functionalization of white phosphorus by organolithium reagents to organophosphorus compounds, including three parts: (i) the development of P₄ functionalization by organo-mono-lithium reagents, and the recent breakthroughs for the synergistic activation strategy of Lewis acid and organo-mono-lithium reagents; (ii) the new discovery of organo-di-lithium reagents mediated P₄ activation, including the aggregation states of products, reaction mechanism and derivatization reactions; and (iii) modes of organolithium reagents mediated P₄ activation. This timely review will accelerate the development of P₄ functionalization for the construction of organophosphorus compounds.