Day: December 2, 2022

Liao, Jennie published the artcileTransforming Benzylic Amines into Diarylmethanes: Cross-Couplings of Benzylic Pyridinium Salts via C-N Bond Activation, Application In Synthesis of 197958-29-5, the publication is Organic Letters (2018), 20(10), 3030-3033, database is CAplus and MEDLINE.

A nickel-catalyzed cross-coupling of benzylic pyridinium salts with arylboronic acids was developed. Coupled with chemoselective pyridinium formation, this method allows benzyl primary amines to be efficiently converted to di(hetero)arylmethanes, e.g., I. Excellent heteroaryl and functional group tolerance is observed, and a one-pot procedure enables benzylic amines to be converted to diarylmethanes directly.

Organic Letters published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C5H6BNO2, Application In Synthesis of 197958-29-5.

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

Liu, Lei published the artcilePalladium-catalyzed C-H trifluoromethylselenolation of arenes with [Me₄N][SeCF₃] and an oxidant, Application In Synthesis of 89076-64-2, the publication is Chemical Communications (Cambridge, United Kingdom) (2022), 58(66), 9238-9241, database is CAplus and MEDLINE.

Trifluoromethylselenolation of arenes with [Me₄N][SeCF₃] in the presence of an oxidant through Pd-catalyzed C(sp²)-H activation under the assistance of a directing group is established for the first time. The reaction tolerates different directing groups and a variety of functional groups, enabling selective installation of a SeCF₃ moiety onto the ortho positions of arenes. Mechanistic studies revealed that the CF₃SeSeCF₃ intermediate in situ generated from oxidation of [Me₄N][SeCF₃] might be the real SeCF₃ reagent in the reaction.

Chemical Communications (Cambridge, United Kingdom) published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, Application In Synthesis of 89076-64-2.

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

Kong, Fanji published the artcileEffects of Additives on Catalytic Arene C-H Activation: Study of Rh Catalysts Supported by Bis-phosphine Pincer Ligands, HPLC of Formula: 338800-13-8, the publication is Organometallics (2020), 39(21), 3918-3935, database is CAplus.

Hydrogen-deuterium exchange (H/D exchange) is a method commonly used for studying catalytic activation of C-H(D) bonds by transition metal complexes. In this study, a series of additives were studied for H/D exchange of toluene-d₈ with acetic acid (HOAc) using (^RPNP)Rh(X) complexes (R = phosphine substituents including cyclohexyl, iso-Pr and tert-butyl; X = trifluoroacetate or acetate) as the precatalysts. Cu(OAc)₂ and AgOAc additives were found to benefit Rh-mediated C-H(D) activation of toluene with meta-para selectivity by facilitating the conversion to active (^RPNP)Rh species and stabilizing the Rh catalysts from decomposition to inactive Rh(s). In contrast, nonoxidizing Lewis acid additives, such as B(OMe)₃ or NaOAc, were not effective at facilitating Rh-catalyzed toluene C-H activation. The complexes (^RPNP)Rh^III(H)(X)₂ and [(^RPNP)Rh^I(CO)][X] (X = TFA or OAc) were found to be intermediates of the catalytic the H/D exchange.

Organometallics published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C23H43NP2, HPLC of Formula: 338800-13-8.

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

Oliveira, Isabel B. published the artcileToxicity of emerging antifouling biocides to non-target freshwater organisms from three trophic levels, Recommanded Product: Triphenyl(pyridin-1-ium-1-yl)borate, the publication is Aquatic Toxicology (2017), 164-174, database is CAplus and MEDLINE.

Antifouling (AF) systems provide the most cost-effective protection against biofouling. Several AF biocides have, however, caused deleterious effects in the environment. Subsequently, new compounds have emerged that claim to be more environment-friendly, but studies on their toxicity and environmental risk are necessary in order to ensure safety. This work aimed to assess the toxicity of three emerging AF biocides, tralopyril, triphenylborane pyridine (TPBP) and capsaicin, towards non-target freshwater organisms representing three trophic levels: algae (Chlamydomonas reinhardtii), crustacean (Daphnia magna) and fish (Danio rerio). From the three tested biocides, tralopyril had the strongest inhibitory effect on C. reinhardtii growth, effective quantum yield and ATP (ATP) content. TPBP caused sub-lethal effects at high concentrations (100 and 250μg L^-1), and capsaicin had no significant effects on algae. In the D. magna acute immobilization test, the most toxic compound was TPBP. However, tralopyril has a short half-life and quickly degrades in water. With exposure solution renewals, tralopyril’s toxicity was similar to TPBP. Capsaicin did not cause any effects on daphnids. In the zebrafish embryo toxicity test (zFET) the most toxic compound was tralopyril with a 120 h – LC₅₀ of 5μg L^-1. TPBP’s 120 h – LC₅₀ was 447.5μg L^-1. Capsaicin did not cause mortality in zebrafish up to 1 mg L^-1. Sub-lethal effects on the proteome of zebrafish embryos were analyzed for tralopyril and TPBP. Both general stress-related and compound-specific protein changes were observed Five proteins involved in energy metabolism, eye structure and cell differentiation were commonly regulated by both compounds Tralopyril specifically induced the upregulation of 6 proteins implicated in energy metabolism, cytoskeleton, cell division and mRNA splicing while TPBP lead to the upregulation of 3 proteins involved in cytoskeleton, cell growth and protein folding. An ecol. risk characterization was performed for a hypothetical freshwater marina. This anal. identified capsaicin as an environment-friendly compound while tralopyril and TPBP seem to pose a risk to freshwater ecosystems. Noneless, more studies on the characterization of the toxicity, behavior and fate of these AF biocides in the environment are necessary since this information directly affects the outcome of the risk assessment.

Aquatic Toxicology 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 C23H20BN, Recommanded Product: Triphenyl(pyridin-1-ium-1-yl)borate.

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

Lopez-Fontal, Elkin published the artcileShip in a bottle: confinement-promoted self-assembly, HPLC of Formula: 636-73-7, the publication is Chemical Science (2018), 9(7), 1760-1768, database is CAplus and MEDLINE.

Understanding self-assembly in confined spaces is essential to fully understand mol. processes in confined cell compartments and will offer clues on the behavior of simple confined systems, such as protocells and lipid-vesicle based devices. Using a model system composed of lipid vesicles, a membrane impermeable receptor and a membrane-permeable ligand, we have studied in detail how compartmentalization modulates the interaction between the confined receptor and its ligand. We demonstrate that confinement of one of the building blocks stabilizes complex self-assembled structures to the extent that dilution leads, counterintuitively, to the formation of long range assemblies. The behavior of the system can be explained by considering a confinement factor that is analogus, although not identical, to the effective molarity for intramol. binding events. The confinement effect renders complex self-assembled species robust and persistent under conditions where they do not form in bulk solution Moreover, we show that the formation of stable complex assemblies in systems compartmentalized by semi-permeable membranes does not require the prior confinement of all components, but only that of key membrane impermeable building blocks. To use a macroscopic analogy, lipid vesicles are like ship-in-a bottle constructs that are capable of directing the assembly of the confined ship following the confinement of a few key wooden planks. Therefore, we believe that the confinement effect described here would have played an important role in shaping the increase of chem. complexity within protocells during the first stages of abiogenesis. Addnl., we argue that this effect can be exploited to design increasingly efficient functional devices based on comparatively simple vesicles for applications in biosensing, nanoreactors and drug delivery vehicles.

Chemical Science 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, HPLC of Formula: 636-73-7.

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

Williams, Jack L. R. published the artcilePhotochemical decomposition of triphenylboron and its complexes, HPLC of Formula: 971-66-4, the publication is Journal of the American Chemical Society (1967), 89(17), 4538, database is CAplus.

In the direct photolysis of triphenylboron (I) in solution and N atm. by 2537 A. radiation, the formation of hydrocarbon products depended on the nature of the solvent. With I in cyclohexane, the products were only phenol and phenylboronic acid. When I was irradiated in MeOH solution, biphenyl and diene mixtures of products were obtained in low yields. Under similar conditions in MeOH solution, the piperidine complex of I yielded 32% biphenyl, 26% 1-phenyl-1,3-cyclohexadiene, 23% 1-phenyl-1,4-cyclohexadiene, and a small amount of 2-phenyl-1,3-cyclohexadiene. Similarly, the pyridine complex of I gave 63% biphenyl, 10% 1-phenyl-1,4-cyclohexadiene, 7% 3-phenyl-1,4-cyclohexadiene, and 4% 1-phenyl-1,3-cyclohexadiene. Since the absorption maximum of I depended also on the nature of the solvent, it was concluded that the alc. mol. donated an electron pair to the B atom to promote the “ate”-type photochem. rearrangement.

Journal of the American Chemical Society 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 C17H16O2, HPLC of Formula: 971-66-4.

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

Blanchard, Stephanie published the artcileDihydrodipyridopyrazines: synthesis and functionalization, Safety of 2-Bromopyridin-3-amine, the publication is Studii si Cercetari Stiintifice: Chimie si Inginerie Chimica, Biotehnologii, Industrie Alimentara (Universitatea Bacau) (2010), 11(1), 45-65, database is CAplus.

This paper is a combination of the authors’ prior published work with new exptl. material. Different conceptual synthetic approaches to the elaboration of a new family of planar polynuclear nitrogen containing aromatic heterocycles – the dihydrodipyridopyrazines – are reviewed: the arynic reaction, the sequence palladium coupling reaction – substitution – reduction – cyclization – substitution or via Smiles rearrangement. Further functionalization of these compounds by substitution reaction, metalation sequence and palladium-catalyzed coupling reaction are also discussed.

Studii si Cercetari Stiintifice: Chimie si Inginerie Chimica, Biotehnologii, Industrie Alimentara (Universitatea Bacau) published new progress about 39856-58-1. 39856-58-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Bromide,Amine, name is 2-Bromopyridin-3-amine, and the molecular formula is C5H5BrN2, Safety of 2-Bromopyridin-3-amine.

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

Dauben, William G. published the artcileFluorinated chirons for vitamin D₃ syntheses. A serendipitous synthesis of a 9α-hydroxy derivative of (7Z)-vitamin D₃, Application In Synthesis of 107263-95-6, the publication is Journal of Organic Chemistry (1992), 57(5), 1597-600, database is CAplus.

The synthesis of three fluorinated vitamin D₃ C/D-ring precursors I, II, and III is reported. A serendipitous synthesis of a 9α-hydroxy derivative of (7Z)-vitamin D₃ from a fluorinated precursor is described.

Journal of Organic Chemistry 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, Application In Synthesis of 107263-95-6.

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

Hershko, Chaim published the artcilePhenolic ethylenediamine derivatives: a study of orally effective iron chelators, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Journal of Laboratory and Clinical Medicine (1984), 103(3), 337-46, database is CAplus and MEDLINE.

Of 35 potential iron chelators screened for in vivo activity in rats, a group of phenolic compounds with excellent chelating properties were identified. These included N,N‘-ethylene-bis(o-hydroxyphenylglycine) (EHPG) [1170-02-1], NN‘-Bis(o-hydroxybenzyl)-ethylenediamine diacetic acid (HBED) [303-38-8], and their resp. di-Me esters (dmEHPG [90044-13-6] and dmHBED [85120-52-1]. All 4 phenolic compounds produced a marked increase in the fecal excretion of hepatocellular radioiron. This amounted to 42% of total body radioactivity with dmEHPG, 58% with EHPG, 60% with HBED, and 80% with dmHBED after a single injection of 40 mg/animal. At a dose of 5 mg/animal, EHPG, HBED, and dmHBED were 9, 12, and 15 times more potent, resp., than deferoxamine. Both di-Me esters showed significant oral activity: oral dmEHPG retained 1/3 and dmHBED retained 2/3 of the effect of the same dose given by i.m. injection. The ester dmHBED combines oral effectiveness with superior chelating ability, selective hepatocellular action, and low apparent toxicity. It may represent a significant advance in the development of new iron-chelating drugs.

Journal of Laboratory and Clinical Medicine 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, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.

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

Tomita, M. published the artcileComparative responses of the carotid and vertebral arterial systems of rhesus monkeys to betahistine, Recommanded Product: N-Methyl-2-(pyridin-2-yl)ethan-1-amine dimethanesulfonate, the publication is Stroke (1978), 9(4), 382-7, database is CAplus and MEDLINE.

Following i.v. administration of betahistine mesylate (I) [54856-23-4], the mean transit times of blood through the carotid and vertebral arteries were equally shortened by 10%, despite a 20% decrease in the mean arterial blood pressure. The cerebral tissue and cerebellar tissue blood flow was increased by I 70.4-81.4 and 73.2-84.0 mL/100g/min, resp. Since histamine has been reported to produce a decrease in cardiac output, the increase in cerebral blood flow confirmed that I is a selective cerebral vasodilating agent. However, by comparing the hemodynamic data for the 2 cerebral arterial systems, the responses of the carotid and vertebral arterial systems to the vasodilating action of I were essentially the same.

Stroke published new progress about 54856-23-4. 54856-23-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Amine,Inhibitor,Inhibitor, name is N-Methyl-2-(pyridin-2-yl)ethan-1-amine dimethanesulfonate, and the molecular formula is C7H9BO3S, Recommanded Product: N-Methyl-2-(pyridin-2-yl)ethan-1-amine dimethanesulfonate.

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