Day: December 9, 2022

Liu, Qilun published the artcileAbnormal Mesoionic Carbene Silver Complex: Synthesis, Reactivity, and Mechanistic Insight on Oxidative Fluorination, Recommanded Product: 1-Fluoropyridiniumtriflate, the publication is ACS Catalysis (2015), 5(11), 6732-6737, database is CAplus.

A silver-catalyzed intramol. amination of alkynyl-imine substrates has been extensively studied to build various isoquinoline derivatives efficiently. However, most of these transformations are limited to hydroamination, and the related oxidative reaction is quite rare. Importantly, the mechanistic details are still unknown, which retarded further progress in the field. In this work, a novel abnormal mesoionic carbene silver complex (MIC)_nAg(I) was isolated and fully characterized as the key intermediate. Further investigation on the oxidative transformation of the silver complex reveals that successful oxidative halogenation could be achieved with NXS (X = Cl, Br, and I), as well as F⁺ reagent. Surprisingly, the fluorination reaction occurred in the presence of both strong (SelectFluor) and weak (NFSI) fluorinating reagents, although the F-Py-type reagent, whose oxidative potential lies between, is ineffective. Further mechanistic studies disclosed that (1) from kinetic data, the (MIC)Ag(I) complex was proved to be the reactive intermediate in the fluorination reaction, and pyridyl-oxazoline (Pyox) ligand could significantly improve this transformation; (2) from DFT calculation results, two different mechanistic pathways were suggested to be involved, a metathesis process in the case of NFSI promoted by the chelation of sulfonyl group toward the silver center and a redox process in the case of SelectFluor due to its strong oxidative potential.

ACS Catalysis published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Recommanded Product: 1-Fluoropyridiniumtriflate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Dong, Jie published the artcileManganese-catalysed divergent silylation of alkenes, Application of 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Nature Chemistry (2021), 13(2), 182-190, database is CAplus and MEDLINE.

Transition-metal-catalyzed, redox-neutral dehydrosilylation of alkenes is a long-standing challenge in organic synthesis, with current methods suffering from low selectivity and narrow scope. The authors report a general and simple method for the Mn-catalyzed dehydrosilylation and hydrosilylation of alkenes, with Mn₂(CO)₁₀ as a catalyst precursor, by using a ligand-tuned metalloradical reactivity strategy. This enables versatility and controllable selectivity with a 1:1 ratio of alkenes and silanes, and the synthetic robustness and practicality of this method are demonstrated using complex alkenes and light olefins. The selectivity of the reaction was studied using d. functional theory calculations, showing the use of an ⁱPrPNP ligand to favor dehydrosilylation, while a JackiePhos ligand favors hydrosilylation. The reaction is redox-neutral and atom-economical, exhibits a broad substrate scope and excellent functional group tolerance, and is suitable for various synthetic applications on a gram scale. [graphic not available: see fulltext].

Nature Chemistry published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Application of 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Zhang, Yin published the artcileDimensional Reduction of Eu-Based Metal-Organic Framework as Catalysts for Oxidation Catalysis of C(sp³)-H Bond, Formula: C12H9NO, the publication is Chinese Journal of Chemistry (2022), 40(4), 480-486, database is CAplus.

Developing new catalysts for highly selectivity and conversion of saturated C(sp³)-H bonds is of great significance. In order to obtain catalysts with high catalytic performance, six Eu-based MOFs with different structural characteristics were obtained by using europium ions and different organic acid ligands, namely Eu-1∼Eu-6. Eu-1, Eu-2 and Eu-3 featured three-dimensional structures, while Eu-4 and Eu-5 featured two-dimensional structures. Differently, a one-dimensional chain structure of Eu-6 was obtained by changing the ligand. All the six MOFs were applied to the catalytic reaction of C(sp³)-H bond, and it was found that the catalytic effect was gradually enhanced with the decrease of dimension and the increase of the size of channels. As expected, Eu-6 showed the highest selectivity (∼99%) and conversion (∼99%). Moreover, catalytic cycling and stability tests showed Eu-6 can be a reliable catalyst.

Chinese Journal of Chemistry published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C14H10O4S2, Formula: C12H9NO.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Han, Er-Meng published the artcileMetal-Directed Self-Assembly of {Ti₈L₂} Cluster-Based Coordination Polymers with Enhanced Photocatalytic Alcohol Oxidation Activity, Application In Synthesis of 91-02-1, the publication is Inorganic Chemistry (2022), 61(2), 923-930, database is CAplus and MEDLINE.

Cooperative assembly of the neutral cluster {Ti₈O₅(OEt)₁₈L₂} (L = pyrazine-2,3-dicarboxylic acid) with different metal units of Mn(NO₃)₂, CuCl₂, Zn(OEt)₂, Cd(NO₃)₂, Ce(NO₃)₃, Lu(NO₃)₃, and Lu(NO₃)₂(OEt), or the [Cu₂I₂] cluster, generates a family of Ti-O cluster (TOC)-based coordination polymers. These 1-dimensional (1D) linear structures contain the same {Ti₈L₂} cluster but with variable bridging metal units. The regulation of the heterometal not only affects the chain geometries of the {MTi₈} but also affects the way the 1-dimensional chains are stacked in the crystal lattice. Study of the catalytic activities toward alc. oxidation demonstrated the synergetic effect of combining the metal site and the photosensitive {Ti₈L₂} cluster in the tailored structure. Under light illumination, the {MTi₈} with dual catalytic sites shows greatly enhanced catalytic activity in the selective oxidation of alcs. to aldehydes. Because the compositions and structures of {MTi₈} are highly tunable, this work spotlights the potential of using such metal-bridged multidimensional Ti-oxo materials for cooperative photoredox catalysis for organic transformation.

Inorganic Chemistry published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C12H9NO, Application In Synthesis of 91-02-1.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Hong, Bing published the artcileSedimentary spectrum and potential ecological risks of residual pharmaceuticals in relation to sediment-water partitioning and land uses in a watershed, Quality Control of 21829-25-4, the publication is Science of the Total Environment (2022), 152979, database is CAplus and MEDLINE.

Pharmaceutical residues in river surficial sediment are prone to anthropogenic impacts and environmental factors in watershed, but the mechanisms remain unclear. This study attempted to reveal surficial sediment-water pseudo-partitioning and anthropogenic (land use) patterns of pharmaceutical residues in surficial sediment among 23 subwatersheds of Jiulong River, southeast China with a gradient of urban land use percentile in dry and wet seasons. Thirty-eight out of target 86 compounds from six-category pharmaceuticals were quantified and ranged from below the quantification limits (0.001 mg kg^-1 dry mass) up to 8.19 mg kg^-1 dry mass (chlortetracycline) using a developed SPE-HPLC-MS/MS protocol. Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) collectively dominated sedimentary pharmaceutical residues for 34.5-99.8% of the total quantified compounds (median at 92%). Land uses in subwatersheds showed high consistency with sedimentary pharmaceutical residues in the dry season rather than the wet season, especially for human use only and veterinary use only compounds Surficial sediment-water partitioning of pharmaceutical compounds influenced their sedimentary residues regardless of season, which were determined by properties of compound and surficial sediment interactively. All tetracycline compounds, trimethoprim (sulfonamides synergist), caffeine (central nervous system drug), and oxfendazole (antiparasitic drug) were quantified to pose high potential ecol. risks to aquatics. Findings of this study suggest that pseudo-persistent legacy of human and veterinary pharmaceuticals requires a wider coverage of pharmaceutical compounds for a comprehensive ecol. assessment in the environment and more involvement of anthropogenic impacts and socioeconomic factors in the future studies.

Science of the Total Environment published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Quality Control of 21829-25-4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Hu, Shuzhi published the artcileA fast-response photochromic host-guest coordination polymer with a close-packed stacking structure, Application In Synthesis of 47369-00-6, the publication is CrystEngComm (2016), 18(38), 7221-7224, database is CAplus.

A photochromic phenyl-substituted viologen based derivative that is embedded in a layered zinc-carboxylate framework is shown to have a fast photoswitching behavior. A favorable geometry for intermol. electron transfer is established by the sandwich-type π-π stacking structure between the photoactive host and guest components.

CrystEngComm published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C22H18Cl2N2, Application In Synthesis of 47369-00-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Naito, Yasuyuki published the artcileConstructing vascularized hepatic tissue by cell-assembled viscous tissue sedimentation method and its application for vascular toxicity assessment, Safety of Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, the publication is Acta Biomaterialia (2022), 275-288, database is CAplus and MEDLINE.

In vitro Construction of the liver sinusoidal structure using artificial tissue is an important but worthwhile challenge, particularly for assessing the risk of diseases such as sinusoidal obstruction syndrome (SOS). Current models are unsuitable for evaluating the toxicity because of lacking sinusoidal capillary. In this study, we developed a vascularized hepatic tissue (VHT) using a unique tissue engineering technique, the cell assembled viscous tissue by sedimentation (CAViTs) method. The “viscous bodies” created using the CAViTs method exhibited significant self-assembly within 6 h after seeding, promoting cell-cell interaction. The level of albumin secreted by the VHT was four times higher than that of 2D-coculture and maintained for 1 mo. The gene expression pattern of the VHT was closer to that of total human liver, compared with the 2D system. Quant. evaluations of the vascular structure of VHT treated with two typical SOS-inducing compounds, monocrotaline and retrorsine, revealed higher sensitivity (IC50 = 40.35μM), 19.92 times higher than the cell-viability assay. Thus, VHT represents an innovative in vitro model that mimics the vessel network structure and could become a useful tool for the early screening of compounds associated with a risk of vascular toxicity. Mimicking sinusoidal structures in in vitro liver model is important to consider from the perspective of predicting hepatotoxicity such like sinusoidal obstruction syndrome (SOS). However, it was difficult to reconstruct the vascular structure within the hepatocyte-rich environment. In this study, we constructed a vascularized hepatic tissue in a high-throughput manner by a unique method using collagen and heparin, and evaluated its applicability to toxicity assessment. Vessel morphol. anal. of the model treated by monocrotaline, which is a well-known SOS-inducing compound, could predict the toxicity with higher sensitivity. To the best of our knowledge, this is the first report to provide vascularized hepatic tissues using sinusoidal endothelial cells at least for demonstrating applicability to the evaluation of SOS induction risk.

Acta Biomaterialia published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Safety of Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Owa, Takashi published the artcileSynthesis and biological evaluation of N-(7-indolyl)-3-pyridinesulfonamide derivatives as potent antitumor agents, Formula: C5H5NO3S, the publication is Bioorganic & Medicinal Chemistry Letters (2002), 12(16), 2097-2100, database is CAplus and MEDLINE.

The synthesis and antitumor activity of E7070 analogs containing a 3-pyridinesulfonamide moiety is reported. E7070 was selected from our sulfonamide-based compound collections, currently undergoing Phase II clin. trials because of its tolerable toxicity profile and some antitumor responses in the Phase I setting. Of the analogs examined, ER-35745 (I), a 6-amino-3-pyridinesulfonamide derivative, demonstrated significant oral efficacy against the HCT116 human colon carcinoma xenograft in nude mice.

Bioorganic & Medicinal Chemistry Letters published new progress about 636-73-7. 636-73-7 belongs to pyridine-derivatives, auxiliary class Pyridine,Sulfonic acid, name is Pyridine-3-sulfonic acid, and the molecular formula is C5H5NO3S, Formula: C5H5NO3S.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Kaburaki, Soyoko published the artcileHepatic drug metabolism in older people with body composition changes., Related Products of pyridine-derivatives, the publication is Geriatrics & gerontology international (2022), 22(5), 449-454, database is MEDLINE.

AIM: Dosage adjustment is essential in older individuals because they are prone to experience a decline in liver function and changes in body composition. However, quantitative tests or equations for evaluating the activity of hepatic drug metabolism have not yet been clearly established. We examined hepatic drug metabolism activities in older individuals, focusing on changes in body composition parameters. METHODS: Lansoprazole and nifedipine, substrates of the metabolic enzymes cytochrome P450 (CYP) 2C19 and 3A4, respectively, were selected to study hepatic drug metabolism. Residual samples from blood test for older patients were evaluated to determine drug metabolism. The body composition of relevant patients was determined by analyzing characteristic parameters of skeletal muscle mass index (SMI), handgrip strength (HGS) and hepatic steatosis index (HSI). The differences in hepatic drug metabolism were studied statistically among categories in terms of the cut-off value of these parameters. RESULTS: Older male patients receiving lansoprazole and nifedipine in the low SMI (<7.0 kg/m² ) category showed an 85-90% reduction in respective CYP2C19 and CYP3A4 metabolic activities compared with the normal SMI category. For the female patients, CYP2C19 and CYP3A4 metabolic activities showed no significant correlation with SMI and HGS. Fatty liver disease (HSI ≥36) was found to reduce CYP2C19 metabolic activity particularly in older female patients. CONCLUSIONS: Low CYP2C19 metabolic activity was statistically correlated with low SMI in male patients and high HSI in female patients, whereas low CYP3A4 metabolic activity was statistically correlated with low HGS in male patients. Geriatr Gerontol Int 2022; 22: 449-454.

Geriatrics & gerontology international published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Related Products of pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Takahashi, Kazunobu published the artcileDetermination of release rate of pyridine-triphenylborane (PTPB) from copper-free antifouling paints, COA of Formula: C23H20BN, the publication is Shikizai Kyokaishi (2005), 78(2), 50-57, database is CAplus.

Pyridine-triphenylborane (PTPB) is one of the alternative tin-free antifoulants in marine antifouling paints and was used widely in com. copper-free self-polishing antifouling paints in Japan. Anal. method for determination of PTPB at low ppb level in seawater was developed by HPLC with UV detection at 220 nm after pre-concentration with C18 solid-phase extraction (SPE). PTPB leached from an antifouling paint film was extracted from artificial seawater using a C18 solid-phase extraction (SPE) cartridge, and eluted with acetonitrile/pyridine (99:1). The recoveries of PTPB (25 μg/1 and 50 μg/l) spiked into artificial seawater were 96% and 97%, resp. The limit of determination of PTPB using 100 mL of artificial seawater was 0.5 μg/l for this anal. method. The HPLC-UV using SPE was applied onto measurement of the release rate (μg/cm²/day) of PTPB from copper-free antifouling paints containing PTPB according to both ISO 15181-1 and 15181-2.

Shikizai Kyokaishi published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C6H12N2O, COA of Formula: C23H20BN.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem