Month: October 2022

Chen, Xiaoxia; Cai, Wenjuan; Liu, Gang; Tu, Yayi; Fan, Congbin; Pu, Shouzhi published the artcile< A highly selective colorimetric and fluorescent probe Eu(tdl)2abp for H2S sensing: Application in live cell imaging and natural water>, Category: pyridine-derivatives, the main research area is Eu(tdl)(2)abp; H(2)S; Large stokes shift; Living cells; Natural water.

Using 4-([2,2′: 6′, 2′- terpyridin] -4′-yl) -N, N-dimethylaniline (tdl) as auxiliary ligand and 6-azido-2,2′-bipyridine (abp) as recognition ligand, a europium complex fluorescent probe Eu(4-([2,2′: 6′, 2′-terpyridin] -4′ -yl) -N, N-dimethylaniline)2-6-azido-2,2′-bipyridine Eu(tdl)2abp for efficient and specific recognition of hydrogen sulfide (H2S) was successfully synthesized and characterized by NMR and MS. Eu(tdl)2abp represented “”on-off”” fluorescence signals for H2S and its color changes could be identified with naked eyes. Eu(tdl)2abp had short response time (2 min) to H2S, high selectivity and good anti-interference, large stokes shift (207 nm). In various samples, when H2S existed, the azide group was reduced to amine group, resulting in closed fluorescence signal, and the fluorescence intensity reached the degree of quenching without being affected by other interference. At the same time, there was a good linear relationship between relative fluorescence intensity and H2S concentration with the detection limit (LOD) of 0.64 μM. The sensing mechanism of Eu(tdl)2abp to detect H2S was characterized by 1H NMR and HR-MS. Eu(tdl)2abp was used with success for the sensitive detection of H2S in natural water and living cells.

Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy published new progress about 366-18-7. 366-18-7 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2, Category: pyridine-derivatives.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Saraireh, Ibrahim A. M.; Altarawneh, Mohammednoor; Almatarneh, Mansour H. published the artcile< Thermochemical parameters of chlorinated compounds of pyridine>, Electric Literature of 14121-36-9, the main research area is chlorinated pyridine formation enthalpy charge heat capacity entropy.

Thermochem. and geometrical parameters of all chlorinated compounds of pyridine were calculated with the CBS-QB3 composite method. Standard entropies, standard Gibbs free energies of formation, standard enthalpies of formation, and heat capacities were computed and compared with their corresponding available exptl. data. Our calculated enthalpy values agree well with a rather limited corresponding exptl. data. Adjacent chlorinated sites in pyridine was found to incur a thermodn. penalty of 5.0 kcal/mol. While chlorination of pyridine is carried out at elevated temperatures in the gas and solvent media, acquiring the trend underpinning chlorination sequence at room temperature provides an insightful mechanistic insight. For this reason, we calculated Fukui indexes for electrophilic substitution and attempted to link obtained values with thermodn. stability orderings computed at 25 °C. Overall, the pattern and degree of chlorination induces very minor geometrical differences in reference to the unsubstituted pyridine. Calculated Fukui indexes predicts the chlorination sequence as follows; 2-chloro → 2,5-dichloro → 2,3,6-trichloro → 2,3,5,6-tetrachloro → 2,3,4,5,6-pentachloropyridine. However, a significant pos. charge accumulated in the N atom of the ortho-Wheland-type adduct renders its thermodynamically unstable by 8 kcal/mol in reference to the meta-Wheland intermediate. Overall, the sequence of chlorination is most likely to be sensitive to kinetics factors rather than thermodn. attributes; i.e., energies required to form the Wheland-type intermediates.

Computational & Theoretical Chemistry published new progress about Atomic charge. 14121-36-9 belongs to class pyridine-derivatives, and the molecular formula is C5HCl4N, Electric Literature of 14121-36-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ingale, Ajit P.; Garad, Dnyaneshwar N.; Ukale, Dattatraya; Thorat, Nitin M.; Shinde, Sandeep V. published the artcile< Thiamine hydrochloride as a recyclable organocatalyst for the efficient and chemoselective N-tert-butyloxycarbonylation of amines>, Formula: C6H8N2, the main research area is amine tert butyloxycarbonylation chemoselective thiamine hydrochloride recyclable green organocatalyst.

Thiamine hydrochloride promoted highly efficient and ecofriendly approach has been described for the chemoselective N-tert-butyloxycarbonylation of amines under solvent-free conditions at ambient temperature The demonstrated approach has been applicable for the N-Boc protection of variety of aliphatic, aryl, heteroaryl amines. The chemoselective protection of amino group occurs in chiral amines and amino alc. without racemization in high yield. Thiamine hydrochloride is stable, economical, easy to handle and environmentally friendly.

Synthetic Communications published new progress about Amines Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 3731-53-1 belongs to class pyridine-derivatives, and the molecular formula is C6H8N2, Formula: C6H8N2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Nishiyama, Hisao; Park, Soon-Bong; Haga, Masaaki; Aoki, Katsuyuki; Itoh, Kenji published the artcile< Ruthenium(II)Cl2-bis(oxazolinyl)bipyridine complex. Its structure and reactivity>, Electric Literature of 147409-41-4, the main research area is crystal structure ruthenium oxazolinylbipyridine complex; catalyst dimerization cyclopropanation ruthenium oxazolinylbipyridine complex.

A mixture of [RuCl2(p-cymene)]2 and 6,6′-bis(oxazolinyl)-2,2′-bipyridine (L) was heated in EtOH at 70° to produce RuCl2L, of which structure was clarified by x-ray anal. to show that L coordinates as a tetradentate ligand. Its catalytic activities for transformations of diazoacetates in dimerization and cyclopropanation with styrene were examined and its spectroelectrochem. was studied.

Chemistry Letters published new progress about Crystal structure. 147409-41-4 belongs to class pyridine-derivatives, and the molecular formula is C22H26N4O2, Electric Literature of 147409-41-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Lv, Kang; Jiang, Yuanye; Han, Lingli; Liu, Tao; Bi, Siwei published the artcile< Theoretical study on the base-controlled selective linear or branched ortho-alkylation of azines catalyzed by rhodium: Mechanisms and the role of base>, Application In Synthesis of 3796-23-4, the main research area is azine rhodium catalyst regioselective alkylation mechanism transition state structure.

The detailed theor. study on the mechanism of the alkylation of 3-trifluoromethylpyridine with acrylamide in the [RhI]/dppe catalytic system is reported, with the aid of the d. functional theory (DFT) calculations It is found that the additive bases play a critical role in switching the regioselectivity. The origin of the regioselectivity involved in these reactions was probed by performing distortion-interaction anal. For reaction A with KOPiv as the base, the outer-sphere concerted-metalative-deprotonation (CMD) pathway is calculated to be a bit more favorable kinetically compared with the oxidative addition (OA) one and the two mechanisms are competitive. The regioselectivity in this reaction is predicted to be determined by the distortion energies of the migratory insertion transition states. In contrast, for reaction B with K3PO4 as the base, the feasible pathway is the OA one, and the corresponding interaction energies for the olefin migratory insertion into Rh-H bond step could account for the observed regioselectivity.

Molecular Catalysis published new progress about Alkylation catalysts. 3796-23-4 belongs to class pyridine-derivatives, and the molecular formula is C6H4F3N, Application In Synthesis of 3796-23-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Demonti, Luca; Saffon-Merceron, Nathalie; Mezailles, Nicolas; Nebra, Noel published the artcile< Cross-Coupling through Ag(I)/Ag(III) Redox Manifold>, HPLC of Formula: 3796-23-4, the main research area is silver trifluoromethyl tervalent argentate preparation reductive elimination arylboronate; trifluoromethyl arene preparation coupling arylboronate trifluoromethylargentate reductive elimination; crystal mol optimized electronic structure tervalent trifluoromethyl argentate complex; AgIII chemistry; cross-coupling; fluorine; high-valent species; trifluoromethylation.

Trifluoromethyl argentates(III) undergo reductive elimination with arylboronic acids, yielding trifluoromethylarenes. In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e- redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: (i) easy AgI/AgIII 2e- oxidation mediated by air; (ii) bpy/phen ligation to AgIII; (iii) boron-to-AgIII aryl transfer; and (iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]- (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]- intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.

Chemistry – A European Journal published new progress about Boronic acids, esters Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (arylboronates). 3796-23-4 belongs to class pyridine-derivatives, and the molecular formula is C6H4F3N, HPLC of Formula: 3796-23-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Funk, Bernhard; Kirmayer, David; Sahar-Heft, Sharonit; Gati, Irith; Friedman, Michael; Steinberg, Doron published the artcile< Efficacy and potential use of novel sustained release fillers as intracanal medicaments against Enterococcus faecalis biofilm in vitro>, HPLC of Formula: 123-03-5, the main research area is Enterococcus cetylpyridinium chloride vancomycin biofilm solidification; Cetylpyridinium chloride; E. faecalis biofilm; Intracanal medication; Sustained release.

Enterococcus faecalis is a bacterium frequently isolated after failed root canal therapy. First, the solidification capability was tested by introducing liquid SRF into phosphate buffered saline, followed by 30 s of vortexing. The antimicrobial effects of SRF-CPC against static monospecies biofilms were analyzed with a metabolic assay. Inhibition of biofilm formation was tested by exposing daily refreshed E. faecalis suspensions to SRF-CPC for 9 wk. To evaluate the effects of SRF-CPC against preformed biofilms, biofilms were grown for 1, 3 and 7 days, and then treated with SRF-CPC for 24 h. Biofilm kill time was tested by applying SRF-CPC to a 3-day-old biofilm and measuring its viability at different time points. All experiments were compared to Placebo SRFs and to untreated control biofilms. Data were analyzed with two-way ANOVA followed by Tukey’s test. Results were considered significant at P < 0.05. The liquid SRF solidified within seconds and no structural changes were observed after 30 s of vortexing at maximum speed. SRF-CPC inhibited E. faecalis biofilm formation for 7 wk and significantly reduced its viability in weeks 8 and 9. Mature biofilms grown for 1, 3 and 7 days were destructed by SRF-CPC in less than 24 h. Fifty percent of a 3-day-old biofilm was destructed in 2 h and complete destruction occurred in less than 12 h. SRF-CPC's phys. properties and long-lasting anti-biofilm effects make it a promising coadjuvant medication for endodontic therapy. BMC Oral Health published new progress about Biofilms (microbial), schmutzdecke. 123-03-5 belongs to class pyridine-derivatives, and the molecular formula is C21H38ClN, HPLC of Formula: 123-03-5.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kuehn, Laura; Jammal, Dominik G.; Lubitz, Katharina; Marder, Todd B.; Radius, Udo published the artcile< Stoichiometric and Catalytic Aryl-Cl Activation and Borylation using NHC-stabilized Nickel(0) Complexes>, Related Products of 329214-79-1, the main research area is bond activation aryl chloride borylation nickel NHC complex catalyst; crystal structure mol nickel heterocyclic carbene complex preparation; bond activation; boronates; borylation; carbene ligands; homogeneous catalysis; nickel.

NHC-nickel (NHC = N-heterocyclic carbene) complexes are efficient catalysts for the C-Cl bond borylation of aryl chlorides using NaOAc as a base and B2pin2 (pin = pinacolato) as the boron source. The catalysts [Ni2(ICy)4(μ-(η2:η2)-COD)] (1, ICy = 1,3-dicyclohexylimidazolin-2-ylidene; COD = 1,5-cyclooctadiene), [Ni(ICy)2(η2-C2H4)] (2), and [Ni(ICy)2(η2-COE)] (3, COE = cyclooctene) compare well with other nickel catalysts reported previously for aryl-chloride borylation with the advantage that no further ligands had to be added to the reaction. Borylation also proceeded with B2neop2 (neop = neopentylglycolato) as the boron source. Stoichiometric oxidative addition of different aryl chlorides to complex 1 was highly selective affording trans-[Ni(ICy)2(Cl)(Ar)] (Ar = 4-(F3C)C6H4, 11; 4-(MeO)C6H4, 12; C6H5, 13; 3,5-F2C6H3, 14).

Chemistry – A European Journal published new progress about Aryl chlorides Role: RCT (Reactant), RACT (Reactant or Reagent). 329214-79-1 belongs to class pyridine-derivatives, and the molecular formula is C11H16BNO2, Related Products of 329214-79-1.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Saeidikhoo, Sara; Ezi, Samira; Khatmi, Aysan; Aghajanpour, Fakhroddin; Soltani, Reza; Abdollahifar, Mohammad Amin; Jahanian, Ali; Aliaghaei, Abbas published the artcile< Effect of Sertoli Cell Transplantation on Reducing Neuroinflammation-Induced Necroptosis and Improving Motor Coordination in the Rat Model of Cerebellar Ataxia Induced by 3-Acetylpyridine>, Quality Control of 350-03-8, the main research area is acetylpyridine antiinflammatory agent neuroinflammation cerebellar ataxia; Cell transplantation; Cerebellar ataxia; Neurodegeneration; Sertoli cells.

To date, no certain cure has been found for patients with degenerative cerebellar disease. In this trial, we examined the in vivo and in vitro neuroprotective effects of Sertoli cells (SCs) on alleviating the symptoms of cerebellar ataxia. Testicular cells from an immature male rat were isolated and characterized by immunocytochem. anal. for somatic cell markers (anti-Mullerian hormone, vimentin). The protein assessment had already confirmed the expression of neurotrophic factors of glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial factor (VEGF). In vitro neuroprotective impact of SCs was determined after exposing PC12 cells to Sertoli cell-conditioned media (SC-CM) and H2O2, simultaneously. Afterwards, ataxia rat models were induced by a single dose of 3-AP (3-acetylpyridin), and 3 days later, SCs were bilaterally implanted. Motor and neuromuscular activity test were conducted following SC transplantation. Finally, immunohistochem. against RIPK3 and Iba-1 was done in our generation. The in vivo results revealed substantial improvement in neuromuscular response, while ataxia group exhibited aggravated condition over a 28-day period. Our results suggested enhanced motor function and behavioral characteristics due to the ability of SCs to suppress necroptosis and consequently extend cell survival. Nevertheless, more studies are required to affirm the therapeutic impacts of SC transplantation in human cerebellar ataxia. In vitro data indicated cell viability was increased as a result of SC-CM with a significant reduction in ROS.

Journal of Molecular Neuroscience published new progress about Cell morphology. 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Quality Control of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Chebotarev, Alexander N.; Pliuta, Konstantin V.; Snigur, Denys V. published the artcile< Determination of Carmoisine onto Carbon-Paste Electrode Modified by Silica Impregnated with Cetylpyridinium Chloride>, Safety of 1-Hexadecylpyridin-1-ium chloride, the main research area is carmoisine carbon electrode silica cetylpyridinium chloride soft drinks analysis.

In this paper a simple, cheap and sensitive electrochem. sensor for determination of Carmoisine in soft drinks was developed. Carmoisine is a synthetic azo dye which is used in food products. In this work effective voltammetric sensor based on carbon-paste electrode modified by silica impregnated with cetylpyridinium chloride to increase the sensitivity of Carmoisine detection was proposed. The voltammetric behavior of Carmoisine, the number of protons and electrons involved in the oxidation process were studied. The probable mechanism of Carmoisine oxidation on the developed sensor was suggested. The optimal conditions for the square-wave voltammetric determination of Carmoisine onto developed sensor were found to be: pH=2; Eads=400 mV; tads=300s; A=50 mV; ν=25 Hz, υ=100 mV/s. The calibration curve was linear in the range of Carmoisine concentrations 0,08-1μM. The proposed method was successfully tested in the anal. of Carmoisine in soft drinks with RSD not more than 5%.

ChemistrySelect published new progress about Carbonated beverages. 123-03-5 belongs to class pyridine-derivatives, and the molecular formula is C21H38ClN, Safety of 1-Hexadecylpyridin-1-ium chloride.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem