Day: November 15, 2022

Ucar, Sefa published the artcileTransition Metal-Free Heteroarylation of Quinoxaline: Construction of Heteroaryl-Fused Phenazines by Oxidative Coupling, Formula: C12H8N2S, the main research area is heteroarylquinoxaline preparation quinoxaline heteroarylation transition metal free fluorescence; phenazine heteroaryl fused preparation diheteroarylquinoxaline oxidative coupling fluorescence.

A concise method for the construction of heteroaryl-fused phenazines was developed via PIFA-BF3·Et2O-mediated oxidative coupling of di-heteroarylated quinoxalines for the first time. Synthesis of mono- and di-heteroarylation of quinoxaline was performed effectively using only LiTMP reagent under transition metal-free conditions and without the use of halogen-containing starting compounds In addition, nonsym. di-heteroarylated quinoxalines were synthesized through reheteroarylation of mono-heteroarylated quinoxalines in the same way. Oxidation of the saturated compounds formed after heteroarylation was easily accomplished with iodine. The UV-vis absorption and fluorescence features of some compounds were examined

Journal of Organic Chemistry published new progress about Diastereoselective synthesis. 40353-41-1 belongs to class quinoxaline, name is 2-(Thiophen-2-yl)quinoxaline, and the molecular formula is C12H8N2S, Formula: C12H8N2S.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Satish, Gandhesiri published the artcileI2Cu-mediated self-sorting domino reaction of aryl β-ketoesters into symmetrical 2-carboalkoxy-1,4-enediones: application to synthesis of pyrazine, β-carboline and quinoxalines, Category: quinoxaline, the main research area is enedione preparation stereoselective; ketoester domino reaction iodine copper acetate catalyst; quinoxaline carboline pyrazine preparation; diamine aryl enedione preparation nucleophilic addition iodine catalyst.

A self-sorting domino reaction of aryl β-ketoesters RC6H4C(O)CH2C(O)OCH2CH3 into sym. E:Z mixture of 1,4-enediones RC(O)C(CO2CH2CH3):CHC(O)R was reported by an I2/Cu system. The reaction proceeds through tandem iodination, self-dimerization and Krapcho dealkoxycarbonylation in one pot under open air condition. Further, E:Z mixture of 1,4-enediones RC(O)C(CO2CH2CH3):CHC(O)R were successfully employed for the synthesis of bioactive pyrazine, β-carboline and quinoxalines I via aza-Michael addition, intramol. cyclization and C-C bond cleavage of 1,3-dicarbonyl unit under mild reaction condition.

RSC Advances published new progress about Diastereoselective synthesis. 40353-41-1 belongs to class quinoxaline, name is 2-(Thiophen-2-yl)quinoxaline, and the molecular formula is C12H8N2S, Category: quinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lou, Shao-Jie published the artcilePd(OAc)2-catalyzed regioselective aromatic C-H bond fluorination, Name: 2-(Thiophen-2-yl)quinoxaline, the main research area is palladium acetate catalyzed regioselective aromatic carbon hydrogen bond fluorination.

A novel Pd(OAc)2-NFSI-TFA system was developed for the highly selective ortho-monofluorination directed by diverse aryl-N-heterocyclic directing groups e.g., quinoxaline, pyrazole, benzo[d]oxazole, and pyrazine derivatives A Pd(ii/iv) catalytic cycle was proposed based on the ESI-MS/MS studies.

Chemical Communications (Cambridge, United Kingdom) published new progress about C-H bond activation (aromatic). 40353-41-1 belongs to class quinoxaline, name is 2-(Thiophen-2-yl)quinoxaline, and the molecular formula is C12H8N2S, Name: 2-(Thiophen-2-yl)quinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Borjigin, Naraso published the artcilen- and p-Channel field-effect transistors based on diquinoxalino TTF derivatives, SDS of cas: 39267-05-5, the main research area is diquinoxalino TTF derivative field effect transistor structure optical property.

Three new quinoxalinoTTF derivatives with Me, trifluoromethyl and fluoro groups were synthesized and characterized by UV-visible absorption spectroscopy, DSC, x-ray single crystal anal., x-ray diffraction, and field-effect transistor (FET) characteristics. All of them have π-stacking structures in the single crystals. The quinoxalinoTTF derivative with trifluoromethyl groups exhibited an n-type FET, which is a rare example of n-channel FETs based on TTF derivatives The highest electron mobility is 0.01 cm2 V-1 s. The FET polarity was converted to p-channel from n-channel by replacing the trifluoromethyl groups with Me groups. The hole mobility is ≤0.2 cm2 V-1 s. In contrast, the fluoro substituted derivative did not show FET properties due to the poorly ordered mol. arrangement.

Synthetic Metals published new progress about Differential scanning calorimetry. 39267-05-5 belongs to class quinoxaline, name is 2,3-Dichloro-6-methylquinoxaline, and the molecular formula is C9H6Cl2N2, SDS of cas: 39267-05-5.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Ceccarelli, Stefano published the artcileImidazo[1,2-a]quinoxalin-4-amines: a novel class of nonxanthine A1-adenosine receptor antagonists, Synthetic Route of 25983-14-6, the main research area is imidazoquinoxalinamine preparation A1 adenosine receptor binding.

The syntheses and A1 adenosine receptor affinities of a number of imidazo[1,2-a]quinoxalin-4-amines, e.g., I, are reported. Structure-activity relationships within the series and in comparison with other similar tricyclic nonxanthine adenosine antagonists are discussed, leading to a putative common binding mode of these nitrogen-containing heterocycles to A1 adenosine receptors. Secondary amino compounds displayed the best affinities toward A1 receptors, while the tertiary amines were almost devoid of activity, thus suggesting a crucial role for the hydrogen bond-forming 4-NH group. Remarkably higher potencies for 1-Me and N-cyclopentyl derivatives were also found. I (IRFI 165) is the most potent compound in this series, having Ki(A1) = 7.9 nM. It is also provided with a good A1 selectivity both vs. A2a and A3 subtypes and was selected for further pharmacol. studies.

European Journal of Medicinal Chemistry published new progress about Adenosine A1 receptor antagonists. 25983-14-6 belongs to class quinoxaline, name is 2,3,6,7-Tetrachloroquinoxaline, and the molecular formula is C8H2Cl4N2, Synthetic Route of 25983-14-6.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Monte, Manuel J. S. published the artcileThermodynamic Study on the Sublimation of Six Substituted Quinoxalines, Computed Properties of 25983-14-6, the main research area is quinoxaline derivative sublimation thermodn mass spectrometry Knudsen effusion.

The Knudsen mass-loss effusion technique was used to measure the vapor pressures at different temperatures of the following substituted quinoxalines: 2-hydroxyquinoxaline, between 383.17 K and 399.15 K; 2-hydroxy-3-methylquinoxaline, between 375.16 K and 391.15K; 2,3-dichloroquinoxaline, between 313.15 K and 329.15 K; 2,3,6,7-tetrachloroquinoxaline, between 347.16 K and 361.17 K; 2,3-dimethylquinoxaline between 294.14 K and 308.14 K; 2,3-bis(bromomethyl)quinoxaline, between 351.14 K and 365.14 K. From the temperature dependence of the vapor pressure, the standard molar enthalpies of sublimation at the mean temperature of the exptl. range were derived by the Clausius-Clapeyron equation. From these results the standard molar enthalpies, entropies, and Gibbs functions of sublimation at T = 298.15 K were calculated An empirical equation for estimating vapor pressure-temperature data from enthalpies of sublimation values is presented.

Journal of Chemical and Engineering Data published new progress about Clapeyron equation (standard mol.). 25983-14-6 belongs to class quinoxaline, name is 2,3,6,7-Tetrachloroquinoxaline, and the molecular formula is C8H2Cl4N2, Computed Properties of 25983-14-6.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Podsiadly, Radoslaw published the artcileSynthesis and photochemical reaction of novel, visible-wavelength oxidizable polymerization sensitizer based on the 12H-quinoxalino[2,3-b][1,4]benzothiazine skeleton, Recommanded Product: 2,3,6,7-Tetrachloroquinoxaline, the main research area is quinoxalinobenzothiazine dye sensitized alkoxypyridinium photodecomposition initiator visible light photopolym; photolysis quinoxalinobenzothiazine visible light sensitizer alkoxypyridinium polymerization photoinitiator.

Novel dyes based on the 12H-quinoxalino[2,3-b] [1,4]benzothiazine skeleton were synthesized and subsequently characterized using 1H NMR. Their electrochem. and spectral properties, such as absorption and emission spectra, quantum yield of fluorescence, and quantum yield of singlet oxygen formation, were measured. These compounds were evaluated as sensitizers for alkoxypyridinium salt photodecomposition, and the results are discussed on the basis of the free energy change for electron transfer from benzothiazine dyes to alkoxypyridinium compounds Benzothiazine dyes are useful oxidizable sensitizers for N-alkoxypyridinium photoinitiators. The mechanism of the dye photobleaching is supported by time-dependent d. functional theory (TD-DFT) calculations and the quantum yields of sensitized proton formation. Photoredox pairs consisting of benzothiazine dyes and alkoxypyridinium salt were found to be effective initiation systems for free radical polymerization of Me acrylate and trimethylolpropane triacrylate (TMPTA) using visible light.

Journal of Photochemistry and Photobiology, A: Chemistry published new progress about Absorption spectra (photobleaching). 25983-14-6 belongs to class quinoxaline, name is 2,3,6,7-Tetrachloroquinoxaline, and the molecular formula is C8H2Cl4N2, Recommanded Product: 2,3,6,7-Tetrachloroquinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Laru, Sudip published the artcileRu(II)-Catalyzed Switchable C-H Alkylation and Spirocyclization of 2-Arylquinoxalines with Maleimides via ortho-C-H Activation, Application of 2-(Thiophen-2-yl)quinoxaline, the main research area is arylquinoxaline maleimide ruthenium catalyst regioselective alkylation; quinoxalinylaryl succinimide preparation; maleimide arylquinoxaline ruthenium catalyst regioselective oxidative spirocyclization; spiro indenoquinoxaline pyrrolidinedione preparation.

A Ru(II)-catalyzed facile and controllable protocol for C-H alkylation and spirocyclization of 2-arylquinoxalines with maleimides were achieved under ambient air in high yields. Sequential ortho-C-H activation and C-annulation resulted in the formation of diverse polyheterocycles containing spiro[indeno[1,2-b]quinoxaline-11,3′-pyrrolidine]-2′,5′-diones, which is of potent interest in medicinal chem. Mechanistic investigations suggested a reversible cleavage of the ortho-C-H bond in the turnover-limiting step.

Journal of Organic Chemistry published new progress about Alkylation catalysts, regioselective. 40353-41-1 belongs to class quinoxaline, name is 2-(Thiophen-2-yl)quinoxaline, and the molecular formula is C12H8N2S, Application of 2-(Thiophen-2-yl)quinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lippa, K. A. published the artcileNucleophilic Aromatic Substitution Reactions of Chloroazines with Bisulfide (HS-) and Polysulfides (Sn2-), Quality Control of 25983-14-6, the main research area is chloroazine nucleophilic aromatic substitution reaction bisulfide polysulfide; seawater pollution chloroazine natural remediation nucleophilic reaction bisulfide polysulfide.

Reactions of bisulfide and polysulfides with chloroazines (important constituents of agrochems. and textile dyes) were examined in aqueous solution at 25°. For atrazine, rates are first-order in polysulfide concentration, and polysulfide dianions are the principal reactive nucleophiles; no measurable reaction occurs with HS-. Second-order rate constants for reactions of an array of chloroazines with polysulfides are several orders of magnitude greater than for reactions with HS-. Transformation products indicate the substitution of halogen(s) by sulfur. Ring aza nitrogens substantially enhance reactivity through a combination of inductive and mesomeric effects, and electron-withdrawing or electron-donating substituents markedly enhance or diminish reactivity, resp. The overall second-order nature of the reaction, the products observed, and reactivity trends are all consistent with a nucleophilic aromatic substitution (SNAr) mechanism. Rate constants for reactions with HS- and Sn2- (n = 2-5) correlate only weakly with LUMO (LUMO) energies, suggesting that the electrophilicity of a chloroazine is not the sole determinant of its reactivity. When second-order rate constants are extrapolated to HS- and Sn2- concentrations reported in salt marsh pore waters, half-lives of minutes to years are obtained. Polysulfides in particular could play an important role in effecting abiotic transformations of chloroazines in hypoxic marine waters.

Environmental Science and Technology published new progress about Aquatic sediment pore water (salt marsh). 25983-14-6 belongs to class quinoxaline, name is 2,3,6,7-Tetrachloroquinoxaline, and the molecular formula is C8H2Cl4N2, Quality Control of 25983-14-6.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Ghosh, Subhendu published the artcileAccess to Multifunctional AEEgens via Ru(II)-Catalyzed Quinoxaline-Directed Oxidative Annulation, Safety of 2-(Thiophen-2-yl)quinoxaline, the main research area is ruthenium catalyzed quinoxaline oxidative annulation aggregation induced emission.

Multifaceted application potential of AEEgens in bio-imaging, theranostic, chemo/bio sensors, mechanochromic, solar cells and organic photoelectronic opens up a new research paradigm to develop and design more such compounds Herein, quinoxaline N-directed Ru(II)-catalyzed oxidative annulation of 2-arylquinoxalines with internal alkynes leads to the formation of highly luminescent annulated quaternary ammonium salts in the presence of Cu(OAc)2.H2O oxidant. While the synthesized compounds exhibit emissions in green to yellow region with large Stoke shifts and reasonable quantum yields, their DFT calculation display 3D twisted conformation bearing donor-π-acceptor (D-π-A) configuration, where the two Ph moieties could serve as the donors and the extended quinoxaline core as the acceptor. Single crystal anal. of quaternary salt 3aa, depicts the presence of multiple intermol. non-covalent and weak π-π interactions that are possibly responsible for the luminescent behavior in crystalline as well as solid state. Advent of AEE in quinoxalinium salt 3aa in DMF/water is due to the restriction of intramol. motion (RIM) and suppression of intermol. charge transfer in aggregated state. AEEgen 3aa unveils reversible mechanochromism on changing from crystalline to amorphous state upon grinding and returned back to the crystalline state upon DCM fuming, where a few of such compounds are utilized for development of latent fingerprints on an adhesive tape. Furthermore, a representative group of synthesized luminescent quinoxalinium salts portray dose dependent cell growth inhibition of HeLa cells with concomitant cell arrest in G1 phases. Hence, these AEE luminogens are not only attractive as luminescent “”light-up”” probes for cell imaging, but also important as anticancer agents.

ACS Omega published new progress about Aggregation-induced emission enhancement. 40353-41-1 belongs to class quinoxaline, name is 2-(Thiophen-2-yl)quinoxaline, and the molecular formula is C12H8N2S, Safety of 2-(Thiophen-2-yl)quinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider