Month: October 2022

《Metal-Ligand Cooperativity via Exchange Coupling Promotes Iron- Catalyzed Electrochemical CO2 Reduction at Low Overpotentials》 was written by Derrick, Jeffrey S.; Loipersberger, Matthias; Chatterjee, Ruchira; Iovan, Diana A.; Smith, Peter T.; Chakarawet, Khetpakorn; Yano, Junko; Long, Jeffrey R.; Head-Gordon, Martin; Chang, Christopher J.. Quality Control of 2,6-Dibromopyridine And the article was included in Journal of the American Chemical Society in 2020. The article conveys some information:

Biol. and heterogeneous catalysts for the electrochem. CO2 reduction reaction (CO2RR) often exhibit a high degree of electronic delocalization that serves to minimize overpotential and maximize selectivity over the hydrogen evolution reaction (HER). Here, we report a mol. iron(II) system that captures this design concept in a homogeneous setting through the use of a redox non-innocent terpyridine-based pentapyridine ligand (tpyPY2Me). As a result of strong metal-ligand exchange coupling between the Fe(II) center and ligand, [Fe(tpyPY2Me)]2+ exhibits redox behavior at potentials 640 mV more pos. than the isostructural [Zn(tpyPY2Me)]2+ analog containing the redox-inactive Zn(II) ion. This shift in redox potential is attributed to the requirement for both an open-shell metal ion and a redox non-innocent ligand. The metal-ligand cooperativity in [Fe(tpyPY2Me)]2+ drives the electrochem. reduction of CO2 to CO at low overpotentials with high selectivity for CO2RR (>90%) and turnover frequencies of 100 000 s-1 with no degradation over 20 h. The decrease in the thermodn. barrier engendered by this coupling also enables homogeneous CO2 reduction catalysis in water without compromising selectivity or rates. Synthesis of the two-electron reduction product, [Fe(tpyPY2Me)]0, and characterization by X-ray crystallog., Mossbauer spectroscopy, X-ray absorption spectroscopy (XAS), variable temperature NMR, and d. functional theory (DFT) calculations, support assignment of an open-shell singlet electronic structure that maintains a formal Fe(II) oxidation state with a doubly reduced ligand system. This work provides a starting point for the design of systems that exploit metal-ligand cooperativity for electrocatalysis where the electrochem. potential of redox non-innocent ligands can be tuned through secondary metal-dependent interactions. In the experiment, the researchers used many compounds, for example, 2,6-Dibromopyridine(cas: 626-05-1Quality Control of 2,6-Dibromopyridine)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridine is a relatively complex molecule and exhibits a number of different bands in IR spectra. Among others, the bands characterizing the ν8a and ν19b modes have been found to be sensitive to the coordination or protonation of the molecule. Note that the band that is diagnostic for the PyH+ ion at about 1545 cm− 1 (ν19b mode) does not overlap with any of the other bands.Quality Control of 2,6-Dibromopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Palladium-Catalyzed C-H Alkynylation of Unactivated Alkenes》 was written by Schreib, Benedikt S.; Fadel, Marlene; Carreira, Erick M.. Name: Picolinic acid And the article was included in Angewandte Chemie, International Edition in 2020. The article conveys some information:

Palladium-catalyzed regio- and diastereoselective C-H functionalization with bromoalkynes and electronically unbiased olefins is reported. The picolinamide directing group enables the formation of putative 5 and 6-exo-metallacycles as intermediates to afford monoalkynylated products in up to 91% yield in a stereospecific fashion. The systematic study reveals that substrates with a wide range of substituents on the olefin and bromoalkyne coupling partners are tolerated. Chemoselective transformations were demonstrated for the obtained amides, olefins, and alkynes. In the experiment, the researchers used Picolinic acid(cas: 98-98-6Name: Picolinic acid)

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.Name: Picolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Fricke, Patrick J.; Dolewski, Ryan D.; McNally, Andrew published their research in Angewandte Chemie, International Edition in 2021. The article was titled 《Four-Selective Pyridine Alkylation via Wittig Olefination of Dearomatized Pyridylphosphonium Ylides》.Recommanded Product: 1692-25-7 The article contains the following contents:

Methods to synthesize alkylated pyridines are valuable because these structures are prevalent in pharmaceuticals and agrochems. A distinct approach to construct 4-alkylpyridines using dearomatized pyridylphosphonium ylide intermediates in a Wittig olefination-rearomatization sequence is reported. Pyridine N-activation is key to this strategy, and N-triazinylpyridinium salts enable coupling between a wide variety of substituted pyridines and aldehydes. The alkylation protocol is viable for late-stage functionalization, including methylation of pyridine-containing drugs. This approach represents an alternative to metal-catalyzed sp2-sp3 cross-coupling reactions and Minisci-type processes. In the experiment, the researchers used Pyridin-3-ylboronic acid(cas: 1692-25-7Recommanded Product: 1692-25-7)

Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. Pyridine is widely used in the precursor to agrochemicals and pharmaceuticals. Also, it is used as an important reagent and organic solvent.Recommanded Product: 1692-25-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Bazin, Marc-Antoine; Cojean, Sandrine; Pagniez, Fabrice; Bernadat, Guillaume; Cave, Christian; Ourliac-Garnier, Isabelle; Nourrisson, Marie-Renee; Morgado, Cathy; Picot, Carine; Leclercq, Olivier; Baratte, Blandine; Robert, Thomas; Spath, Gerald F.; Rachidi, Najma; Bach, Stephane; Loiseau, Philippe M.; Le Pape, Patrice; Marchand, Pascal published their research in European Journal of Medicinal Chemistry in 2021. The article was titled 《In vitro identification of imidazo[1,2-a]pyrazine-based antileishmanial agents and evaluation of L. major casein kinase 1 inhibition》.Application of 1692-25-7 The article contains the following contents:

Leishmaniasis constitutes a severe public health problem, with an estimated prevalence of 12 million cases. This potentially fatal disease has a worldwide distribution and in 2012, the fatal Visceral Leishmaniasis (VL) was declared as new emerging disease in Europe, mainly due to global warming, with expected important public health impact. The available treatments are toxic, costly or lead to parasite resistance, thus there is an urgent need for new drugs with new mechanism of action. Previously, we reported the discovery of CTN1122, a potent imidazo[1,2-a]pyrazine-based antileishmanial hit compound targeting L-CK1.2 at low micromolar ranges. Here, we described structurally related, safe and selective compounds endowed with antiparasitic properties, better than miltefosine, the reference therapy by oral route. L-CK1.2 homol. model gave the first structural explanations of the role of 4-pyridyl (CTN1122) and 2-aminopyrimidin-4-yl (compound 21) moieties, at the position 3 of the central core, in the low micromolar to nanomolar L-CK1.2 inhibition, whereas N-methylpyrazole derivative 11 remained inactive against the parasite kinase. The experimental process involved the reaction of Pyridin-3-ylboronic acid(cas: 1692-25-7Application of 1692-25-7)

Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. In industry and in the lab, pyridine is used as a reaction solvent, particularly when its basicity is useful, and as a starting material for synthesizing some herbicides, fungicides, and antiseptics.Application of 1692-25-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kassel, Vincent M.; Hanneman, Christopher M.; Delaney, Connor P.; Denmark, Scott E. published an article in 2021. The article was titled 《Heteroaryl-Heteroaryl Suzuki-Miyaura Anhydrous Cross-Coupling Reactions Enabled by Trimethyl Borate》, and you may find the article in Journal of the American Chemical Society.Product Details of 1692-25-7 The information in the text is summarized as follows:

Reaction conditions have been developed for refractory heteroaryl-heteroaryl Suzuki-Miyaura cross-couplings. The reported method employs neopentyl heteroarylboronic esters as nucleophiles, heteroaryl bromides and chlorides as the electrophiles, and the soluble base potassium trimethylsilanolate (TMSOK) under anhydrous conditions. The addition of tri-Me borate enhances reaction rates by several mechanisms, including (1) solubilization of in situ-generated boronate complexes, (2) preventing catalyst poisoning by the heteroat. units, and (3) buffering the inhibitory effect of excess TMSOK. The use of this method enables cross-coupling of diverse reaction partners including a broad range of π-rich and π-deficient heteroaryl boronic esters and heteroaryl bromides. Reactions proceed in good yields and short reaction times (3 h or less). The results came from multiple reactions, including the reaction of Pyridin-3-ylboronic acid(cas: 1692-25-7Product Details of 1692-25-7)

Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. When pyridine is adsorbed on oxide surfaces or in porous materials, the following species are commonly observed: (i) pyridine coordinated to Lewis acid sites, (ii) pyridine H-bonded to weakly acidic hydroxyls, and (iii) protonated pyridine. At high coverage, physisorbed pyridine and protonated dimers can also be observed.Product Details of 1692-25-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Watanabe, Hiroyuki; Tanaka, Kazuo; Chujo, Yoshiki published an article in 2021. The article was titled 《The Effect of the Substituent Positions on Self-Assembly Behaviors of Liquid-Crystalline 1,3,4,6,9b-Pentaazaphenalene Derivatives》, and you may find the article in Bulletin of the Chemical Society of Japan.Synthetic Route of C5H7N3 The information in the text is summarized as follows:

The syntheses and phase transition behaviors of liquid crystals composed of triangular π;-conjugated mols., 1,3,4,6,9b-pentaazaphenalene (5AP) was discussed. Three types of 5AP derivatives having 3,4,5-tris(dodecyloxy)phenyl ((OC12)3Ph) were prepared by changing substituent positions. From thermal and structural analyses, liquid crystalline phases were observed from all derivatives According to structural data and phase transition behaviors, it was suggested that the positions of the substituents significantly influence mol. alignments in liquid crystals as well as thermal properties. In particular, the columnar structures, which were favorable for expressing efficient carrier transportation, were observed in the 5AP derivative These results suggested that the 5AP scaffold could be a platform for constructing a variety of aggregated structures by slightly different patterns of the mol. structures. Plausible models for these transitions were discussed. The experimental process involved the reaction of 2,6-Diaminopyridine(cas: 141-86-6Synthetic Route of C5H7N3)

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.Synthetic Route of C5H7N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Reference of 2-Bromo-5-methylpyridineIn 2022 ,《Potassium tert-butoxide promoted regioselective deuteration of pyridines》 appeared in Chemical Communications (Cambridge, United Kingdom). The author of the article were Li, Yan; Zheng, Chenxu; Jiang, Zhi-Jiang; Tang, Jianbo; Tang, Bencan; Gao, Zhanghua. The article conveys some information:

A regioselective deuteration at the β- and γ-position of pyridines was reported. Efficient deuteration occurred with a combination of KOtBu and DMSO-d6, replenishing the prevailing α-deuteration of the pyridine systems. Preliminary mechanistic studies suggested that the dimsyl carbanion acts as one of the key intermediates. The experimental part of the paper was very detailed, including the reaction process of 2-Bromo-5-methylpyridine(cas: 3510-66-5Reference of 2-Bromo-5-methylpyridine)

2-Bromo-5-methylpyridine(cas: 3510-66-5) belongs to pyridine. The basicity and metallophilic high donor number of these π-deficient systems has long favored them as ligands in metal catalysis. The last decade saw pyridine assume a stronger role as functional group for directed C–H oxidation/activation.Reference of 2-Bromo-5-methylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of 2,5-DibromopyridineIn 2022 ,《Controlling the Complexity and Interconversion Mechanisms in Self-Assembled [Fe2L3]4+ Helicates and [Fe4L6]8+ Cages》 was published in Angewandte Chemie, International Edition. The article was written by Siddique, Rashid G.; Arachchige, Kasun S. A.; Al-Fayaad, Hydar A.; Thoburn, John D.; McMurtrie, John C.; Clegg, Jack K.. The article contains the following contents:

Self-assembled coordination cages and metal-organic frameworks have relied extensively on sym. ligands in their formation. Here the authors prepared a relatively simple system employing an unsym. ligand that results in two distinct self-assembled structures, a [Fe2L3]4+ helicate and a [Fe4L6]8+ cage composed of 10 interconverting diastereomers and their enantiomers. The steric profile of the ligand controls the complexity, thermodn. and kinetics of interconversion of the system. In the experiment, the researchers used 2,5-Dibromopyridine(cas: 624-28-2Safety of 2,5-Dibromopyridine)

2,5-Dibromopyridine(cas: 624-28-2) belongs to pyridine. Pyridine and pyridine-derived structures are privileged pharmacophores in medicinal chemistry and an essential functionality for organic chemists. As the prototypical π-deficient heterocycle, pyridine illustrates distinctive chemistry as both substrate and reagent. Safety of 2,5-Dibromopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application In Synthesis of Methyl 3-chloropicolinateOn June 1, 2015, Kozlov, Maxim V.; Kleymenova, Alla A.; Romanova, Lyudmila I.; Konduktorov, Konstantin A.; Kamarova, Kamila A.; Smirnova, Olga A.; Prassolov, Vladimir S.; Kochetkov, Sergey N. published an article in Bioorganic & Medicinal Chemistry Letters. The article was 《Pyridine hydroxamic acids are specific anti-HCV agents affecting HDAC6》. The article mentions the following:

Recently we reported benzohydroxamic acids (BHAs) as potent and selective inhibitors of hepatitis C virus (HCV) replicon propagation. In this work 12 pyridine hydroxamic acids (PHAs) e. g., I, were synthesized and tested in full-genome replicon assay. It was found that PHAs possessed very similar anti-HCV properties compared to BHAs. Both classes of hydroxamic acids caused hyperacetylation of α-tubulin pointing to inhibition of histone deacetylase 6 (HDAC6) as part of their antiviral activity. The tested compounds did not inhibit the growth of poliovirus, displaying high selectivity against HCV. After reading the article, we found that the author used Methyl 3-chloropicolinate(cas: 116383-98-3Application In Synthesis of Methyl 3-chloropicolinate)

Methyl 3-chloropicolinate(cas: 116383-98-3) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Application In Synthesis of Methyl 3-chloropicolinate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Harper, Kaid C.; Vilardi, Sarah C.; Sigman, Matthew S. published an article on February 20 ,2013. The article was titled 《Prediction of Catalyst and Substrate Performance in the Enantioselective Propargylation of Aliphatic Ketones by a Multidimensional Model of Steric Effects》, and you may find the article in Journal of the American Chemical Society.Computed Properties of C7H11ClN2 The information in the text is summarized as follows:

The effectiveness of a new asym. catalytic methodol. is often weighed by the number of diverse substrates that undergo reaction with high enantioselectivity. Here we report a study that correlates substrate and ligand steric effects to enantioselectivity for the propargylation of aliphatic ketones. The math. model is shown to be highly predictive when applied to substrate/catalyst combinations outside the training set. After reading the article, we found that the author used (6-Methylpyridin-2-yl)methanamine hydrochloride(cas: 1365836-53-8Computed Properties of C7H11ClN2)

(6-Methylpyridin-2-yl)methanamine hydrochloride(cas: 1365836-53-8) belongs to anime. Reaction with nitrous acid (HNO2), which functions as an acylating agent that is a source of the nitrosyl group (―NO), converts aliphatic primary amines to nitrogen and mixtures of alkenes and alcohols corresponding to the alkyl group in a complex process. This reaction has been used for analytical determination of primary amino groups in a procedure known as the Van Slyke method.Computed Properties of C7H11ClN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem