Month: October 2022

Formula: C5H3Br2NIn 2021 ,《Synthesis and Studies of Stable Nonaromatic Dithia Pyribenzihexaphyrins》 was published in Journal of Organic Chemistry. The article was written by Rawat, Nisha; Sinha, Avisikta; Prasannan, Dijo; Ravikanth, Mangalampalli. The article contains the following contents:

We report here one of the rare examples of expanded hexaphyrins named as dithia pyribenzihexaphyrin macrocycles containing six-membered rings such as pyridine and p-phenylene along with five-membered heterocycles such as pyrrole and thiophene as a part of a macrocyclic frame. Trifluoroacetic acid catalyzed [3+3] condensation of equimolar mixture of [10,10′-bis(p-tert-Bu phenyl)hydroxymethyl]-1,3-bis(2-thienyl)pyridine diol (2,6-pyri diol) and 1,4-bis(phenyl(1H-pyrrol-2-yl)methyl)benzene (p-benzidipyrrane) in CH2Cl2 followed by oxidation with DDQ afforded stable nonaromatic dithia 2,6-pyri-para-benzihexapyrins and in 6-8% yields. The macrocycles were characterized by high-resolution mass spectroscopy and 1D and 2D NMR spectroscopy. NMR studies revealed the nonaromatic nature of dithia 2,6-pyri-p-benzihexaphyrins and indicated that the para-phenylene ring prefers to be in quininoid form rather than in benzenoid form. The macrocycles displayed sharp absorption bands in the region of ~380-500 nm and a broad band at ~700 nm, reflecting their nonaromatic nature. Upon protonation, these macrocycles showed NIR absorption properties. The redox studies of macrocycles indicated their electron-deficient nature. The DFT/TD-DFT studies are in line with the exptl. observations. The experimental part of the paper was very detailed, including the reaction process of 2,6-Dibromopyridine(cas: 626-05-1Formula: C5H3Br2N)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Formula: C5H3Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of Picolinic acidIn 2019 ,《Red Blood Cell Metabolic Responses to Torpor and Arousal in the Hibernator Arctic Ground Squirrel》 was published in Journal of Proteome Research. The article was written by Gehrke, Sarah; Rice, Sarah; Stefanoni, Davide; Wilkerson, Rebecca B.; Nemkov, Travis; Reisz, Julie A.; Hansen, Kirk C.; Lucas, Alfredo; Cabrales, Pedro; Drew, Kelly; D’Alessandro, Angelo. The article contains the following contents:

Arctic ground squirrels provide a unique model to investigate metabolic responses to hibernation in mammals. During winter months these rodents are exposed to severe hypothermia, prolonged fasting, and hypoxemia. In the light of their role in oxygen transport/off-loading and owing to the absence of nuclei and organelles (and thus de novo protein synthesis capacity), mature red blood cells have evolved metabolic programs to counteract physiol. or pathol. hypoxemia. However, red blood cell metabolism in hibernation has not yet been investigated. Here we employed targeted and untargeted metabolomics approaches to investigate erythrocyte metabolism during entrance to torpor to arousal, with a high resolution of the intermediate time points. We report that torpor and arousal promote metabolism through glycolysis and pentose phosphate pathway, resp., consistent with previous models of oxygen-dependent metabolic modulation in mature erythrocytes. Erythrocytes from hibernating squirrels showed up to 100-fold lower levels of biomarkers of reperfusion injury, such as the pro-inflammatory dicarboxylate succinate. Altered tryptophan metabolism during torpor was here correlated to the accumulation of potentially neurotoxic catabolites kynurenine, quinolinate, and picolinate. Arousal was accompanied by alterations of sulfur metabolism, including sudden spikes in a metabolite putatively identified as thiorphan (level 1 confidence)-a potent inhibitor of several metalloproteases that play a crucial role in nociception and inflammatory complication to reperfusion secondary to ischemia or hemorrhage. Preliminary studies in rats showed that i.v. injection of thiorphan prior to resuscitation mitigates metabolic and cytokine markers of reperfusion injury, etiol. contributors to inflammatory complications after shock. In addition to this study using Picolinic acid, there are many other studies that have used Picolinic acid(cas: 98-98-6Safety of Picolinic acid) was used in this study.

Picolinic acid(cas: 98-98-6) is used as a chelate for alkaline earth metals. Used to prepare picolinato ligated transition metal complexes. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction.Safety of Picolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formula: C7H5NIn 2019 ,《Screening of Three Transition Metal-Mediated Reactions Compatible with DNA-Encoded Chemical Libraries》 was published in Helvetica Chimica Acta. The article was written by Favalli, Nicholas; Bassi, Gabriele; Zanetti, Tania; Scheuermann, Joerg; Neri, Dario. The article contains the following contents:

The construction of DNA-encoded chem. libraries (DECLs) crucially relies on the availability of chem. reactions, which are DNA-compatible and which exhibit high conversion rates for a large number of diverse substrates. In this work, we present our optimization and validation procedures for three copper and palladium-catalyzed reactions (Suzuki cross-coupling, Sonogashira cross-coupling, and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC)), which have been successfully used by our group for the construction of large encoded libraries. The results came from multiple reactions, including the reaction of 4-Ethynylpyridine(cas: 2510-22-7Formula: C7H5N)

4-Ethynylpyridine(cas: 2510-22-7) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Formula: C7H5N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Recommanded Product: 626-05-1In 2022 ,《Synthesis and Structural Properties of NIR-Absorbing Pyridine-Containing Heptaphyrins》 was published in Chemistry – An Asian Journal. The article was written by Rawat, Nisha; Sinha, Avisikta; Ravikanth, Mangalampalli. The article contains the following contents:

Four examples of stable nonaromatic pyridine containing heteroheptaphyrins (pyrithiaheptaphyrins) 2-5 were synthesized in 8-13% yields by [5+2] condensation of newly synthesized pyridine-based pentapyrrane 8 and bithiophene diol 9 a-d. The X-ray crystallog. anal. of macrocycle 2 proved that the macrocycle assumes a highly planar structure with two inverted thiophene rings. The heteroheptaphyrins 2-5 are asym. and showed a greater number of resonances in 1H NMR spectra compared to our previously reported sym. heterohexaphyrin (pyrithiahexaphyrin) 1 c. Most of the macrocyclic core protons in pyrithiahepaphyrins 2-5 experienced upfield/downfield shifts compared to pyrithiahexaphyrin 1 c indicating the alteration of π-conjugation in the macrocycles. The absorption bands were significantly red-shifted and located in the NIR region in macrocycles 2-5 compared to 1 c supporting the increase of π-delocalization. The theor. studies support the exptl. findings and NICS(0) value supports the non-aromaticity of the macrocycles. In the experimental materials used by the author, we found 2,6-Dibromopyridine(cas: 626-05-1Recommanded Product: 626-05-1)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Recommanded Product: 626-05-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application of 141-86-6In 2019 ,《Excellent toughening of 2,6-diaminopyridine derived poly (urethane urea) via dynamic cross-linkages and interfering with hydrogen bonding of urea groups from partially coordinated ligands》 was published in Polymers (Basel, Switzerland). The article was written by Sun, Ailing; Guo, Wenjuan; Zhang, Jinping; Li, Wenjuan; Liu, Xin; Zhu, Hao; Li, Yuhan; Wei, Liuhe. The article contains the following contents:

Conventional approaches to synthesize thermoplastic polyurethane (TPU) with excellent robustness are limited by a competing relationship between soft and hard segments for tuning mech. properties in terms of chain flexibility and micro-phase separation Herein, we present a facile and effective way of simultaneously improving the tensile strength, elongation, and toughness by constructing dynamic cross-linkages from metal-ligand interaction between Zn2+ and pyridine moiety in backbone of poly(urethane urea) (PUU) derived from 2,6-diaminopyridine and poly(propylene glycol). It was found that a Zn2+/pyridine ratio of 1:4 is the most effective for improving robustness. Specifically, tensile strength, elongation, and toughness could be remarkably increased to 16.0 MPa, 1286%, and 89.3 MJ/m3 with 226%, 29%, and 185% increments compared to uncomplexed PUU, resp. Results from UV-vis, Fourier transform IR spectroscopy (FTIR), cyclic tensile tests, and stress relaxation reveal that metal-ligand interaction significantly interferes with the hydrogen bonding of urea groups, thus leading to weakening of stiffness. Furthermore, half of vacant ligands enable dynamic complexation during stretching, which consequently ensures constant noncovalent cross-linkages for constraining mutual chain sliding, contributing to simultaneous improvement of tensile strength, elongation, and toughness. This work provides a promising approach for designing TPU with excellent robustness. In the experiment, the researchers used 2,6-Diaminopyridine(cas: 141-86-6Application of 141-86-6)

2,6-Diaminopyridine(cas: 141-86-6) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Application of 141-86-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of 4-AcetylpyridineIn 2022 ,《Thioamide synthesis via copper-catalyzed C-H activation of 1,2,3-thiadiazoles enabled by slow release and capture of thioketenes》 was published in Organic Chemistry Frontiers. The article was written by Lu, Changhui; Li, Xiaohong; Chang, Shunqin; Zhang, Yuqi; Xing, Donghui; Wang, Shuo; Lin, Yueping; Jiang, Huanfeng; Huang, Liangbin. The article contains the following contents:

A Cu-catalyzed thioacylation of amines via a C-H activation/coordinated stabilization protocol to ensure the slow-release of thioketenes, which are captured by various amines to afford thioamides was developed. This method was characterized by its simplicity, efficiency and broad substrate scope in both 1,2,3-thiadiazoles and amines. Its versatility was further illustrated by the late-stage thioamidation of N-containing drugs, peptides, catalysts, and ligands. Mechanism studies demonstrate that the active Cu(I) species was formed via the reduction of Cu(II) during the induction period, and the rate-determining step was the C-H activation of 1,2,3-thiadiazole. In the part of experimental materials, we found many familiar compounds, such as 4-Acetylpyridine(cas: 1122-54-9Safety of 4-Acetylpyridine)

4-Acetylpyridine(cas: 1122-54-9) belongs to pyridine. Pyridines, quinolines, and isoquinolines have found a function in almost all aspects of organic chemistry. Pyridine has found use as a solvent, base, ligand, functional group, and molecular scaffold. As structural elements, these moieties are potent electron-deficient groups, metal-directing functionalities, fluorophores, and medicinally important pharmacophores. Safety of 4-Acetylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Chiral Hexahalogenated 4,4′-Bipyridines》 was written by Mamane, V.; Peluso, P.; Aubert, E.; Cossu, S.; Pale, P.. Name: 5-Bromo-2-chloropyridineThis research focused ontrihalopyridine dimerization; bipyridinedione regioselective halogenation copper Finkelstein reaction catalyst; bipyridine hexahalogenated preparation kinetic resolution; chiral hexahalogenated bipyridine preparation. The article conveys some information:

The preparation of 27 isomers of chiral hexahalogeno-4,4′-bipyridines by means of two complementary methods is described. The first one is convergent and based on the LDA-induced 4,4′-dimerization of trihalopyridines, whereas the second method is divergent and achieved through regioselective halogenation reactions of 4,4′-bipyridine-2,2′-diones. Iodine in 2,2′-positions of the 4,4′-bipyridines was introduced by a copper-catalyzed Finkelstein reaction (Buchwald procedure) performed on 2,2′-dibromo derivatives Selected compounds of this new family of atropisomeric 4,4′-bipyridines were enantiosepd. by high performance liquid chromatog. on chiral stationary phases, and the absolute configurations of the separated enantiomers were assigned by using X-ray diffraction anal. The latter revealed that various halogen bond types are responsible for crystal cohesion. In the experiment, the researchers used 5-Bromo-2-chloropyridine(cas: 53939-30-3Name: 5-Bromo-2-chloropyridine)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Additionally, pyridine-based natural products continue to be discovered and studied for their properties and to understand their biosynthesis.Name: 5-Bromo-2-chloropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Endowing 2,6-bis-triazolyl-pyridine of poor extraction with superior efficiency for actinide/lanthanide separation at high acidity by anchoring to a macrocyclic scaffold》 was written by Cai, Yimin; Yan, Qiang; Wang, Mengxin; Chen, Jing; Fu, Haiying; Ye, Jiawei; Conradson, Steven D.; Yuan, Lihua; Xu, Chao; Feng, Wen. Formula: C5H3Br2NThis research focused ontriazolylpyridine macrocyclic scaffold extractant solvent extraction actinide lanthanide separation; Actinide; Lanthanide; N-donor ligand; Separation; Solvent extraction. The article conveys some information:

Exploring nitrogen-containing extractants for recovering hazardous minor actinides that are workable in solutions of high acidity has been a challenge in nuclear waste treatment. Herein, we report our findings that 2,6-bis-triazolyl-pyridine (PyTri), which is ineffective as a hydrophobic ligand for minor actinide separation, turns into an excellent extractant that exhibits unexpectedly high efficiency and selectivity (SFAm/Eu = 172, 1 M HNO3) when attaching to pillar[5]arene platform. Surprisingly, the distribution ratio of Am(III) (DAm) is 4300 times higher than that of the acyclic PyTri ligand. The solvent extraction performance of this pillar[5]arene-achored PyTri not only far exceeds the best known pillar[5]arene ligands reported to date, but also stays comparable to other reported outstanding extractants. Slope anal. indicates that each P[5]A-PyTri can bind two metal ions, which is further corroborated by spectroscopic characterizations. Thermodn. studies imply that the extraction process is exothermic and spontaneous in nature. Complexation investigation via EXAFS technique and DFT calculations strongly suggest that each Eu(III) ion is coordinated to three PyTri arms through a nine-coordination mode. This work provides a N-donor extractant that can operate at high acidity for minor actinide partitioning and implicates a promising approach for transforming poor extractants into superior ones.2,6-Dibromopyridine(cas: 626-05-1Formula: C5H3Br2N) was used in this study.

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Additionally, pyridine-based natural products continue to be discovered and studied for their properties and to understand their biosynthesis.Formula: C5H3Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Proximity effects in pyridines. Proton chemical shifts in substituted methyl pyridinecarboxylates》 was published in Organic Magnetic Resonance in 1975. These research results belong to Deady, L. W.; Harrison, P. M.; Topsom, R. D.. HPLC of Formula: 29681-39-8 The article mentions the following:

The chem. shifts in 6 series of substituted Me pyridinecarboxylates were measured and interpreted in terms of proximity effects. The shifts for ring H ortho and para to the substituent were explained by additive ester, nitrogen, and substituent effects. The results for meta H indicated substituent-nitrogen interactions, especially when both substituent and H were adjacent N. Similar results were obtained for the ester H. The experimental part of the paper was very detailed, including the reaction process of Methyl 5-methoxypicolinate(cas: 29681-39-8HPLC of Formula: 29681-39-8)

Methyl 5-methoxypicolinate(cas: 29681-39-8) belongs to pyridine. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Additionally, pyridine-based natural products continue to be discovered and studied for their properties and to understand their biosynthesis.HPLC of Formula: 29681-39-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Zinc-Chelating Small Molecules Preferentially Accumulate and Function within Pancreatic β Cells》 was written by Horton, Timothy M.; Allegretti, Paul A.; Lee, Sooyeon; Moeller, Hannah P.; Smith, Mark; Annes, Justin P.. Electric Literature of C12H13N3This research focused onzinc DYRK1A insulin pharmacophore pancreatic beta cell; chelation; diabetes; islet; targeted compound delivery; targeting; tissue selectivity; zinc; β cell; β-cell regeneration; β-cell-replication. The article conveys some information:

Diabetes is a hyperglycemic condition characterized by pancreatic β-cell dysfunction and depletion. Whereas methods for monitoring β-cell function in vivo exist, methods to deliver therapeutics to β cells are lacking. We leveraged the rare ability of β cells to concentrate zinc to preferentially trap zinc-binding mols. within β cells, resulting in β-cell-targeted compound delivery. We determined that zinc-rich β cells and islets preferentially accumulated TSQ (6-methoxy-8-p-toluenesulfonamido-quinoline) in a zinc-dependent manner compared with exocrine pancreas. Next, we asked whether appending a zinc-chelating moiety onto a β-cell replication-inducing compound was sufficient to confer preferential β-cell accumulation and activity. Indeed, the hybrid compound preferentially accumulated within rodent and human islets in a zinc-dependent manner and increased the selectivity of replication-promoting activity toward β cells. These data resolve the fundamental question of whether intracellular accumulation of zinc-chelating compounds is influenced by zinc content. Furthermore, application of this principle yielded a proof-of-concept method for β-cell-targeted drug delivery and bioactivity. The experimental part of the paper was very detailed, including the reaction process of Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0Electric Literature of C12H13N3)

Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0) is a secondary amine with two picolyl substituents. The compound is a tridentate ligand in coordination chemistry and commonly used to produce Zn-based chemosensors/probes, such as Zinpry.Electric Literature of C12H13N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem