Day: October 21, 2022

Kim, Sangmin; Loose, Florian; Bezdek, Mate J.; Wang, Xiaoping; Chirik, Paul J. published the artcile< Hydrogenation of N-Heteroarenes Using Rhodium Precatalysts: Reductive Elimination Leads to Formation of Multimetallic Clusters>, Synthetic Route of 3796-23-4, the main research area is phenylpyridinyl benzoquinolinyl cyclometalated pentamethylcyclopentadienylrhodium hydride multinuclear preparation crystal structure; hydrogenation heteroarene rhodium precatalyst reductive multimetallic rhodium cluster; crystal mol structure pentamethylcyclopentadienylrhodium multimetallic cluster.

A rhodium-catalyzed method for the hydrogenation of N-heteroarenes is described. A diverse array of unsubstituted N-heteroarenes including pyridine, pyrrole, and pyrazine, traditionally challenging substrates for hydrogenation, were successfully hydrogenated using the organometallic precatalysts, [(η5-C5Me5)Rh(N-C)H] (N-C = 2-phenylpyridinyl (ppy) or benzo[h]quinolinyl (bq)). In addition, the hydrogenation of polyaromatic N-heteroarenes exhibited uncommon chemoselectivity. Studies into catalyst activation revealed that photochem. or thermal activation of [(η5-C5Me5)Rh(bq)H] induced C(sp2)-H reductive elimination and generated the bimetallic complex, [(η5-C5Me5)Rh(μ2,η2-bq)Rh(η5-C5Me5)H]. In the presence of H2, both of the [(η5-C5Me5)Rh(N-C)H] precursors and [(η5-C5Me5)Rh(μ2,η2-bq)Rh(η5-C5Me5)H] converted to a pentametallic rhodium hydride cluster, [(η5-C5Me5)4Rh5H7], the structure of which was established by NMR spectroscopy, x-ray diffraction, and neutron diffraction. Kinetic studies on pyridine hydrogenation were conducted with each of the isolated rhodium complexes to identify catalytically relevant species. The data are most consistent with hydrogenation catalysis prompted by an unobserved multimetallic cluster with formation of [(η5-C5Me5)4Rh5H7] serving as a deactivation pathway.

Journal of the American Chemical Society published new progress about Aromatic hydrocarbons Role: RCT (Reactant), RACT (Reactant or Reagent) (N-heteroarenes). 3796-23-4 belongs to class pyridine-derivatives, and the molecular formula is C6H4F3N, Synthetic Route of 3796-23-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Mora Vargas, Jorge Andres; Ortega, Julieth Orduna; Correia dos Santos, Maite Bernardo; Metzker, Gustavo; Gomes, Eleni; Boscolo, Mauricio published the artcile< A new synthetic methodology for pyridinic sucrose esters and their antibacterial effects against Gram-positive and Gram-negative strains>, Synthetic Route of 93-60-7, the main research area is sucrose pyridinic monoester antibacterial effect gram pos neg bacteria; Acoustic cavitation; Antibacterial activity; Homogeneous catalysis; Pyridinic methyl esters; ucrose esters.

Described are the development of a new synthetic method using ultrasonic irradiation and Na methoxide as catalyst for pyridinic sucrose esters (py-SEs), derived from transesterification of sucrose with picolinic, nicotinic and isonicotinic Me esters. The reaction was optimized using a 32 x 2 exptl. design, the reaction time, temperature and sucrose:Me ester molar ratio being evaluated. The method proved to be efficient for obtaining monosubstituted esters (≥83%) with high Me ester consumption (≥79%). The monosubstituted py-SEs were isolated by semipreparative HPLC, characterized by high-resolution mass spectrometry, calorimetry, vibrational spectroscopy, and 1H and 13C NMR. The py-SEs were tested against E. coli, S. aureus, and P. aeruginosa bacteria with min. inhibitory concentration values equal or inferior to the reference drugs for both E. coli and P. aeruginosa.

Carbohydrate Research published new progress about Antibacterial agents. 93-60-7 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO2, Synthetic Route of 93-60-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Rezania, Hamidreza; Vatanpour, Vahid; Salehi, Ehsan; Gavari, Niloofar; Shockravi, Abbas; Ehsani, Morteza published the artcile< Wholly Heterocycles-Based Polyamide-Sulfide Containing Pyridine and Thiazole Rings: A Super-Adsorbent Polymer for Lead Removal>, Related Products of 350-03-8, the main research area is lead polyamide sulfide pyridine polymer adsorbent thermal property.

Wholly heterocycles-based polyamide-sulfide (PAS) containing pyridine and thiazole rings with thioether linkage was synthesized and used as a novel adsorbent for lead ion removal from water. The polymer adsorbent was fully characterized via FTIR, NMR and SEM (SEM). The thermal properties of the synthesized polyamide were also studied by thermogravimetric anal. and the outcome showed that the polymer has a good to moderate thermal stability. The SEM was used to investigate the morphol. of the wholly heterocycles-based polyamide and the outcomes displayed a porous and globular-like morphol., which guarantee effective metal adsorption. Pb(II) ion removal capacity of the synthesized polymer was studied by varying the contact time and the adsorbent concentration The maximum removal of Pb(II) was obtained as 99%. Equilibrium behavior and kinetic of the adsorption were also investigated using prevalent isotherm and kinetic models. The adsorption capacity was obtained to be around 714 mg g-1. The Langmuir isotherm and the pseudo-second order kinetic model suggested superior agreement with the equilibrium and kinetic adsorption data, resp. Generally, the results of this research demonstrated that the synthesized polymer is a super-adsorbent for heavy metal removal from water.

Journal of Polymers and the Environment published new progress about Adsorption (Langmuir isotherm). 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Related Products of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Lozovan, Vasile; Kravtsov, Victor Ch.; Gorincioi, Elena; Rotaru, Andrei; Coropceanu, Eduard B.; Siminel, Nikita; Fonari, Marina S. published the artcile< Chromism, positional, conformational and structural isomerism in a series of Zn(II) and Cd(II) coordination polymers based on methylated azine N,N'-donor linkers>, Synthetic Route of 350-03-8, the main research area is zinc cadmium pyridinylethylidenehydrazine iodide nitrate polymer preparation luminescence; thermal stability zinc cadmium pyridinylethylidenehydrazine iodide nitrate polymer; crystal structure zinc cadmium pyridinylethylidenehydrazine iodide nitrate polymer.

Seven new coordination polymers [Zn(I)2(4-bpmhz)]n (1), [Cd(I)2(4-bpmhz)]n (2), [Zn(I)2(3-bpmhz)]n (3), [Cd(I)2(3-bpmhz)2]n (4), [Zn(NO3)2(H2O)2(4-bpmhz)]n·0.5n(EtOH) (5), [Cd(NO3)2(4-bpmhz)3/2(MeOH)]n·0.5nH2O (6) and [Zn(NO3)2(3-bpmhz)2]n (7) were prepared following the reactions of the zinc and cadmium iodide or nitrate salts with the methylated azine ligands of the bis-monodentate N,N’-donor type, 1,2-bis(1-(pyridin-4-yl)ethylidene)hydrazine (4-bpmhz) and 1,2-bis(1-(pyridin-3-yl)ethylidene)hydrazine (3-bpmhz). The single-crystal X-ray diffraction studies show that compounds 1-5, and 7 display 1D chain structures, while compound 6 shows a 2D coordination network, and both 4-bpmhz and 3-bpmhz act as bidentate bridging ligands. The crystals 1 and 2 are isomorphous, and differ by the metal cation only. The single coordination chains in 1-3 have zigzag structures; they are linear in 5, while 4 and 7 display similar double-chain structures. The crystal packing in 5 and 6 provides cavities occupied by solvent mols., ethanol and water. The compounds were characterized in the solid state and in solution by spectroscopic (FTIR, UV-Vis, NMR) methods; the solid state emissive properties were studied for all compounds, while their thermal stability and behavior were investigated by thermogravimetry under inert atm., while the thermochromism for several compounds was registered and discussed.

Polyhedron published new progress about Conformers. 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Synthetic Route of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Zhang, Yangmin; Yang, Hanmin; Chi, Quan; Zhang, Zehui published the artcile< Nitrogen-Doped Carbon-Supported Nickel Nanoparticles: A Robust Catalyst to Bridge the Hydrogenation of Nitriles and the Reductive Amination of Carbonyl Compounds for the Synthesis of Primary Amines>, Related Products of 3731-53-1, the main research area is primary amine preparation; nitrogen doped carbon supported nickel nanoparticle catalyst preparation; nitrile aldehyde hydrogenation reductive amination; amines; hydrogenation; nickel; nitrogen-doped carbon; reductive amination.

An efficient method was developed for the synthesis of primary amines either from the hydrogenation of nitriles or reductive amination of carbonyl compounds The reactions were catalyzed by nitrogen-doped mesoporous carbon (MC)-supported nickel nanoparticles (abbreviated as MC/Ni). The MC/Ni catalyst demonstrated high catalytic activity for the hydrogenation of nitriles into primary amines in high yields (81.9-99 %) under mild reaction conditions (80° and 2.5 bar H2). The MC/Ni catalyst also promoted the reductive amination of carbonyl compounds for the synthesis of primary amines at 80° and 1 bar H2. The hydrogenation of nitriles and the reductive amination proceeded through the same intermediates for the generation of the primary amines. To the best of knowledge, no other heterogeneous non-noble metal catalysts have been reported for the synthesis of primary amines under mild conditions, both from the hydrogenation of nitriles and reductive amination.

ChemSusChem published new progress about Aryl aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 3731-53-1 belongs to class pyridine-derivatives, and the molecular formula is C6H8N2, Related Products of 3731-53-1.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Shao, Zhihui; Zhong, Rui; Ferraccioli, Raffaella; Li, Yibiao; Liu, Qiang published the artcile< General and Phosphine-Free Cobalt-Catalyzed Hydrogenation of Esters to Alcohols>, Application In Synthesis of 93-60-7, the main research area is ester cobalt catalyst hydrogenation; lactone cobalt catalyst hydrogenation; alc preparation.

The first non-noble metal catalytic system that enabled an efficient hydrogenation of non-activated esters to alcs. in the absence of phosphine ligands (with a maximum turnover number of 2391) was described. The general applicability of this protocol was demonstrated by the high-yielding hydrogenation of 39 ester substrates including aromatic/aliphatic esters, lactones, polyesters and various pharmaceutical mols.

Chinese Journal of Chemistry published new progress about Alcohols Role: PRP (Properties), SPN (Synthetic Preparation), PREP (Preparation). 93-60-7 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO2, Application In Synthesis of 93-60-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Breitenbach, Benjamin B.; Steiert, Elena; Konhaeuser, Matthias; Vogt, Lea-Marie; Wang, Yujen; Parekh, Sapun H.; Wich, Peter R. published the artcile< Double stimuli-responsive polysaccharide block copolymers as green macrosurfactants for near-infrared photodynamic therapy>, Application In Synthesis of 2127-03-9, the main research area is polysaccharide copolymer surfactant photodynamic therapy nearinfrared radiation.

The NIR absorbing photosensitizer phthalocyanine zinc (PC(Zn)) was stabilized in aqueous media as water-dispersible nanoparticles with a reduction- and pH-responsive full polysaccharide block copolymer. A cellular uptake and also photo switchable intracellular activity of the cargo upon irradiation at wavelengths in the near IR region were shown. The block copolymer was synthesized by applying a copper-free click strategy based on a thiol exchange reaction, creating an amphiphilic double-stimuli-responsive mixed disulfide. The dual-sensitive polysaccharide micelles represent a non-toxic and biodegradable green macrosurfactant for the delivery of phthalocyanine zinc. By encapsulation into micellar nanoparticles, the bioavailability of PC(Zn) increased significantly, enabling smart photodynamic therapy for future applications in cancer-related diseases.

Soft Matter published new progress about Bioavailability. 2127-03-9 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2S2, Application In Synthesis of 2127-03-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

He, Chengzhi; Li, Shuai; Gao, Xiaoqing; Xiao, Adam; Hu, Chunguang; Hu, Xiaodong; Hu, Xiaotang; Li, Hongbin published the artcile< Direct observation of the fast and robust folding of a slipknotted protein by optical tweezers>, Computed Properties of 2127-03-9, the main research area is slipknotted protein folding optical tweezer direct observation.

Understanding the folding mechanism of knotted and slipknotted proteins has attracted considerable interest. Due to their topol. complexity, knotted and slipknotted proteins are predicted to fold slowly and involve large topol. barriers. Mol. dynamics simulation studies suggest that a slipknotted conformation can serve as an important intermediate to help greatly reduce the topol. difficulty during the folding of some knotted proteins. Here we use a single mol. optical tweezers technique to directly probe the folding of a small slipknotted protein AFV3-109. We found that stretching AFV3-109 can lead to the untying of the slipknot and complete unfolding of AFV3-109. Upon relaxation, AFV3-109 can readily refold back to its native slipknot conformation with high fidelity when the stretching force is lower than 6 pN. The refolding of AFV3-109 occurs in a sharp two-state like transition. Our results indicate that, different from knotted proteins, the folding of a slipknotted protein like AFV3-109 can be fast, and may not necessarily involve a high topol. barrier.

Nanoscale published new progress about Denaturation. 2127-03-9 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2S2, Computed Properties of 2127-03-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Nishiyama, Hisao published the artcile< Synthesis and reactivity of organometallic complexes with C2-symmetrical optically active nitrogen-ligands. Asymmetric catalytic oxidation>, Name: 6,6′-Bis(4-(S)-isopropyl-2-oxazolinyl)-2,2′-bipyridine, the main research area is ruthenium oxazolinyl pyridine catalyst asym oxidation; oxazolinyl bipyridine ruthenium catalyst asym oxidation.

Two types of optically active nitrogen-ligands having C2-symmetry, bis(oxazolinyl)pyridine (Pybox) and bis(oxazolinyl)bipyridine (Bipymox), were developed for asym. catalytic reactions. The nitrogen ligands gave stable complexes by the reaction with ruthenium(II) chloride complex. The structures of the Pybox- and Bipymox-ruthenium complexes were analyzed by x-ray and electrochem. Their complexes of ruthenium(II) exhibited strong activities of oxidation of secondary alcs. and epoxidation of olefins with asym. induction. During this study, highly efficient enantioselective hydrosilylation of ketones and cyclopropanation reaction were discovered.

Asahi Garasu Zaidan Josei Kenkyu Seika Hokoku published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 147409-41-4 belongs to class pyridine-derivatives, and the molecular formula is C22H26N4O2, Name: 6,6′-Bis(4-(S)-isopropyl-2-oxazolinyl)-2,2′-bipyridine.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Schubert, S.; Brans, R.; Reich, A.; Hansen, A.; Buhl, T.; Skudlik, C.; Mempel, M.; Schoen, M. P.; John, S. M.; Geier, J. published the artcile< Assessment of occupational exposure and spectrum of contact sensitization in metalworkers with occupational dermatitis: results of a cohort study within the OCCUDERM project>, Recommanded Product: 2-Mercaptopyridinen-oxide sodiumsalt, the main research area is occupational exposure contact sensitization dermatitis.

Background : Metalworkers occupationally exposed to metals, tools, metalworking fluids (MWFs), tech. oils, gloves, skin care products etc. frequently suffer from occupational dermatitis (OD). Objectives : To investigate occupational exposure and to identify relevant occupational sensitizers in metalworkers with OD, and to evaluate suitability of current German patch test recommendations for this occupational group. Patients and methods : As part of the OCCUDERM project, occupational exposure of 230 metalworkers with suspected OD patch tested in the departments of dermatol. in Goettingen and Osnabrueck (both Lower Saxony, Germany) in 2012-2017 was recorded by questionnaire. These data, as well as results, of patch testing with standardized allergens and with workplace material were analyzed. Results : Metalworking fluids and skin care products were the most important exposures. Among MWF allergens, most frequently sensitizations to formaldehyde and formaldehyde releasers, colophony/abietic acid and monoethanolamine were observed Sensitization to methylisothiazolinone (MI) was frequent, probably as part of the general European epidemic of contact allergy to MI in leave-on cosmetics. Sensitization to glove ingredients only played a minor role. Conclusions : The known occupational allergen spectrum could largely be confirmed. In order not to miss relevant sensitizations, patch testing with material from the patients workplaces in parallel to baseline and MWF series is recommended. Sensitizations diagnosed could not always be linked to particular occupational exposures.

Journal of the European Academy of Dermatology and Venereology published new progress about Allergic contact dermatitis. 3811-73-2 belongs to class pyridine-derivatives, and the molecular formula is C5H4NNaOS, Recommanded Product: 2-Mercaptopyridinen-oxide sodiumsalt.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem