Tag: 100-200

APTRA-Based Luminescent Lanthanide Complexes Displaying Enhanced Selectivity for Mg²⁺ was written by Walter, Edward R. H.;Williams, J. A. Gareth;Parker, David. And the article was included in Chemistry – A European Journal in 2018.Safety of (4-Bromopyridin-2-yl)methanol This article mentions the following:

A series of three europium(III) complexes has been created in which an APTRA moiety has been integrated into the sensitizing chromophore (APTRA=o-aminophenol-N,N,N-triacetate). The constitutionally isomeric complexes EuL¹ and EuL² feature the APTRA unit linked to a metal-bound pyridine ring through an alkynyl unit, differing according to the disposition of the APTRA substituents relative to the C C unit (para-N and para-O). In EuL³, the APTRA ring is directly bonded to the Eu-coordinated pyridine (para-O). The metal binding affinities for magnesium, calcium and zinc ions have been measured by using emission and excitation spectroscopy. The pyridylalkynylaryl systems, EuL¹ and EuL², offer superior affinity and selectivity for Mg²⁺. The Mg²⁺ affinities are surprisingly very different from prior studies on structurally related systems that incorporate organic fluorophores as reporters, as opposed to the macrocyclic Eu complex moiety. A much-reduced affinity for calcium and zinc-possibly arising from the lower donor ability of the aryl N or O atoms arising from extended conjugation-means that magnesium ion concentrations can be measured directly in serum for the first time, by using such an approach. An apparent dissociation constant for magnesium binding of K_d=2.4 mM was calculated in the serum background. In the experiment, the researchers used many compounds, for example, (4-Bromopyridin-2-yl)methanol (cas: 131747-45-0Safety of (4-Bromopyridin-2-yl)methanol).

(4-Bromopyridin-2-yl)methanol (cas: 131747-45-0) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ闁荤姾娅ｅΛ纭俵闂? in pyridine vs. 150 kJ闁荤姾娅ｅΛ纭俵闂? in benzene). Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Safety of (4-Bromopyridin-2-yl)methanol

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

High-Throughput Screening of Earth-Abundant Water Reduction Catalysts toward Photocatalytic Hydrogen Evolution was written by Motz, Rachel N.;Lopato, Eric M.;Connell, Timothy U.;Bernhard, Stefan. And the article was included in Inorganic Chemistry in 2021.Quality Control of Phenyl(pyridin-2-yl)methanone This article mentions the following:

Cobalt(II) glyoxime and heterocycle complexes [Co(LL)₂pyCl]ⁿ⁺ (LL – 婵?dioxime, 8-quinolinols, 婵?diketone dihydrazides, bipyridines, phenanthrolines, pyridyltetrazoles, etc.; n = 0-2) were generated in situ and screened for cocatalytic activity in Eosin Y-catalyzed photoreduction of water in the presence of triethylamine as sacrificial reductant. Noble-metal photosensitizers and water reduction co-catalysts (WRCs) still present the highest activity in homogeneous photocatalytic hydrogen production The search for earth-abundant alternatives is usually limited by the time required to screen new catalyst combinations; however, here, we utilize newly designed and developed high-throughput photoreactors for the parallel synthesis of novel WRCs and colorimetric screening of hydrogen evolution. This unique approach allowed rapid optimization of photocatalytic water reduction using the organic photosensitizer Eosin Y and the archetypal cobaloxime WRC [Co(GL1)₂pyCl], where GL1 is dimethylglyoxime and py is pyridine. Subsequent combinatorial synthesis generated 646 unique cobalt complexes of the type [Co(LL)₂pyCl], where LL is a bidentate ligand, that identified promising new WRC candidates for hydrogen production D. functional theory (DFT) calculations performed on such cobaloxime derivative complexes demonstrated that reactivity depends on hydride affinity. Alkyl-substituted glyoximes were necessary for hydrogen production and showed increased activity when paired with ligands containing strong hydrogen-bond donors. Using a newly developed method of H₂ detection using colorimetric tape, we screened a massive parallel library of cobaloxime water reduction catalysts. This noble-metal-free system of photocatalytic water reduction was optimized using Eosin Y as a photosensitizer. Screening identified a series of intriguing heteroleptic species with high activity, while DFT calculations of potential reaction intermediates correlated the activity of homoleptic cobaloximes to their hydride binding affinity. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1Quality Control of Phenyl(pyridin-2-yl)methanone).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the 闂?bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the 闂?bonds. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Quality Control of Phenyl(pyridin-2-yl)methanone

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Improving the Selectivity of PACE4 Inhibitors through Modifications of the P1 Residue was written by Dianati, Vahid;Navals, Pauline;Couture, Frederic;Desjardins, Roxane;Dame, Anthony;Kwiatkowska, Anna;Day, Robert;Dory, Yves L.. And the article was included in Journal of Medicinal Chemistry in 2018.Product Details of 89809-65-4 This article mentions the following:

Paired basic amino acid cleaving enzyme 4 (PACE4), a serine endoprotease of the proprotein convertases family, has been recognized as a promising target for prostate cancer. We previously reported a selective and potent peptide-based inhibitor for PACE4, named the multi-Leu peptide (Ac-LLLLRVKR-NH₂ sequence), which was then modified into a more potent and stable compound named C23 with the following structure: Ac-DLeu-LLLRVK-Amba (Amba: 4-amidinobenzylamide). Despite improvements in both in vitro and in vivo profiles of C23, its selectivity for PACE4 over furin was significantly reduced. We examined other Arg-mimetics instead of Amba to regain the lost selectivity. Our results indicated that the replacement of Amba with 5-(aminomethyl)picolinimidamide increased affinity for PACE4 and restored selectivity. Our results also provide a better insight on how structural differences between S1 pockets of PACE4 and furin could be employed in the rational design of selective inhibitors. In the experiment, the researchers used many compounds, for example, Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4Product Details of 89809-65-4).

Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Pyridine derivatives are also useful as small-molecule 婵?helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Product Details of 89809-65-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Impact of substituents on molecular properties and catalytic activities of trinuclear Ru macrocycles in water oxidation was written by Meza-Chincha, Ana-Lucia;Lindner, Joachim O.;Schindler, Dorothee;Schmidt, David;Krause, Ana-Maria;Roehr, Merle I. S.;Mitric, Roland;Wuerthner, Frank. And the article was included in Chemical Science in 2020.Computed Properties of C5H3BrFN This article mentions the following:

Herein we report a broad series of new trinuclear supramol. Ru(bda) macrocycles bearing different substituents at the axial or equatorial ligands which enabled investigation of substituent effects on the catalytic activities in chem. and photocatalytic water oxidation Our detailed investigations revealed that the activities of these functionalized macrocycles in water oxidation are significantly affected by the position at which the substituents were introduced. Interestingly, this effect could not be explained based on the redox properties of the catalysts since these are not markedly influenced by the functionalization of the ligands. Instead, detailed investigations by X-ray crystal structure anal. and theor. simulations showed that conformational changes imparted by the substituents are responsible for the variation of catalytic activities of the Ru macrocycles. For the first time, macrocyclic structure of this class of water oxidation catalysts is unequivocally confirmed and exptl. indication for a hydrogen-bonded water network present in the cavity of the macrocycles is provided by crystal structure anal. We ascribe the high catalytic efficiency of our Ru(bda) macrocycles to cooperative proton abstractions facilitated by such a network of preorganized water mols. in their cavity, which is reminiscent of catalytic activities of enzymes at active sites. In the experiment, the researchers used many compounds, for example, 3-Bromo-4-fluoropyridine (cas: 116922-60-2Computed Properties of C5H3BrFN).

3-Bromo-4-fluoropyridine (cas: 116922-60-2) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Computed Properties of C5H3BrFN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Rare-earth catalyzed C-H bond activation and alkylation of pyridines was written by Guan, Bingtao;Hou, Zhaomin. And the article was included in Kidorui in 2012.Quality Control of 2-Isopropylpyridine This article mentions the following:

An efficient and general protocol for the alkylation of various pyridine derivatives via C-H addition to olefins has been developed by the use of cationic half-sandwich rare-earth catalysts, which provides an atom-economical method for the synthesis of alkylated pyridine derivatives A wide range of olefin substrates including ethylene, 婵?olefins, styrenes and conjugated dienes are compatible with the catalysts. The authors have demonstrated that half-sandwich rare-earth dialkyl complexes such as (C₅Me₅)Ln(CH₂C₆H₄NMe₂-o)₂ (Ln = Sc, Y) in combination with an activator such as B(C₆F₅)₃ can serve as an excellent catalyst for the ortho-selective C-H addition of pyridines to a variety of olefins such as 1-alkenes, styrenes and 1,3-conjugated dienes to afford straightforwardly a series of alkylated pyridine derivatives in an atom-economical way. The present rare-earth catalysts are complementary to late transition metal catalysts in terms of selectivity, functional group tolerance and substrate scope. Further studies on rare-earth catalyzed C-H functionalizations with other substrates are in progress. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Quality Control of 2-Isopropylpyridine).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Pyridine derivatives are also useful as small-molecule 婵?helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Quality Control of 2-Isopropylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

闁?Silicon-effect-promoted intermolecular site-selective C(sp³)-H amination with dirhodium nitrenes was written by Ninomiya, Ryo;Arai, Kenta;Chen, Gong;Morisaki, Kazuhiro;Kawabata, Takeo;Ueda, Yoshihiro. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2020.Application In Synthesis of Pyridinehydrochloride This article mentions the following:

A dirhodium-catalyzed, 闁?selective C-H amination of organosilicon compounds was developed. Primary C(sp³)-H bonds of silylethyl groups and secondary C(sp³)-H bonds of silacycloalkanes can be selectively converted to C-N bonds at the 闁?position of the Si atoms. The exptl. data and theor. calculations indicate that the strong 闂?donor ability of the C-Si bonds is responsible for the 闁?selectivity. Kinetic isotope effects clearly demonstrate that the C-H bond cleavage step is not turnover-limiting, but selectivity-determining In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Application In Synthesis of Pyridinehydrochloride).

Pyridinehydrochloride (cas: 628-13-7) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of 闂?8.7 闂?10闂? cm3闁荤姾娅ｅΛ纭俵闂?.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ闁荤姾娅ｅΛ纭俵闂? in the liquid phase and 140.4 kJ闁荤姾娅ｅΛ纭俵闂? in the gas phase. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Application In Synthesis of Pyridinehydrochloride

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Reaction of aromatic N-oxides with dipolarophiles. VII. Effect of aromaticity on 1,3-dipolar cycloaddition reactivity of substituted pyridine N-oxides and preparation of oxazolo[4,5-b]pyridine derivatives was written by Matsuoka, Toshikazu;Shinada, Minoru;Suematsu, Fumihiro;Harano, Kazunobu;Hisano, Takuzo. And the article was included in Chemical & Pharmaceutical Bulletin in 1984.Synthetic Route of C7H9NO This article mentions the following:

The 1,3-dipolar cycloaddition reactivity of pyridine N-oxides to Ph isocyanate was calculated by the MINDO/3 MO method using the perturbation equation derived by Klopman and Salem (1968). The calculation did not predict the low reactivity of acceptor substituted pyridine N-oxides. On the basis of the calculation data, the general 1,3-dipolar cycloaddition reactivity of pyridine N-oxides towards various Ph isocyanates is discussed in terms of the concept of cyclic conjugation. The aromaticity of the pyridine N-oxide may play an important role in determination of the reactivity. In connection with the cycloaddition, the 1,5-sigmatropic rearrangement of the primary cycloadducts and the pyrolytic reaction behavior of the 2,3-dihydropyridine derivatives formed by a 1,5-sigmatropic shift from the primary adducts are discussed on the basis of the MINDO/3 calculation data. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Synthetic Route of C7H9NO).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. Pyridine has a conjugated system of six 闂?electrons that are delocalized over the ring. The molecule is planar and, thus, follows the H闂佹椿浜滈妴鍗l criteria for aromatic systems. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Synthetic Route of C7H9NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Anhydrous Tetramethylammonium Fluoride for Room-Temperature S_NAr Fluorination was written by Schimler, Sydonie D.;Ryan, Sarah J.;Bland, Douglas C.;Anderson, John E.;Sanford, Melanie S.. And the article was included in Journal of Organic Chemistry in 2015.Computed Properties of C6H3FN2 This article mentions the following:

This paper describes the room-temperature S_NAr fluorination of aryl halides and nitroarenes using anhydrous tetramethylammonium fluoride (NMe₄F). This reagent effectively converts aryl-X (X = Cl, Br, I, NO₂, OTf) to aryl-F under mild conditions (often room temperature). Substrates for this reaction include electron-deficient heteroaromatics (22 examples) and arenes (5 examples). The relative rates of the reactions vary with X as well as with the structure of the substrate. However, in general, substrates bearing X = NO₂ or Br react fastest. In all cases examined, the yields of these reactions are comparable to or better than those obtained with CsF at elevated temperatures (i.e., more traditional halex fluorination conditions). The reactions also afford comparable yields on scales ranging from 100 mg to 10 g. A cost anal. is presented, which shows that fluorination with NMe₄F is generally more cost-effective than fluorination with CsF. In the experiment, the researchers used many compounds, for example, 2-Fluoroisonicotinonitrile (cas: 3939-14-8Computed Properties of C6H3FN2).

2-Fluoroisonicotinonitrile (cas: 3939-14-8) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Computed Properties of C6H3FN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Discovery of Novel Central Nervous System Penetrant Metabotropic Glutamate Receptor Subtype 2 (mGlu₂) Negative Allosteric Modulators (NAMs) Based on Functionalized Pyrazolo[1,5-a]pyrimidine-5-carboxamide and Thieno[3,2-b]pyridine-5-carboxamide Cores was written by Childress, Elizabeth S.;Wieting, Joshua M.;Felts, Andrew S.;Breiner, Megan M.;Long, Madeline F.;Luscombe, Vincent B.;Rodriguez, Alice L.;Cho, Hyekyung P.;Blobaum, Anna L.;Niswender, Colleen M.;Emmitte, Kyle A.;Conn, P. Jeffrey;Lindsley, Craig W.. And the article was included in Journal of Medicinal Chemistry in 2019.HPLC of Formula: 51834-97-0 This article mentions the following:

A scaffold hopping exercise from a monocyclic mGlu₂ NAM with poor rodent PK led to two novel heterobicyclic series of mGlu₂ NAMs based on either a functionalized pyrazolo[1,5-a]pyrimidine-5-carboxamide core or a thieno[3,2-b]pyridine-5-carboxamide core. These novel analogs possess enhanced rodent PK, while also maintaining good mGlu₂ NAM potency, selectivity (vs. mGlu₃ and the remaining six mGlu receptors), and high CNS penetration. Interestingly, SAR was divergent between the new 5,6-heterobicyclic systems. In the experiment, the researchers used many compounds, for example, 5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0HPLC of Formula: 51834-97-0).

5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. HPLC of Formula: 51834-97-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Formal umpolung addition of phosphites to 2-azaaryl Ketones under chiral Broensted base catalysis: enantioselective protonation utilizing [1,2]-phospha-Brook rearrangement was written by Kondoh, Azusa;Hirozane, Takayuki;Terada, Masahiro. And the article was included in Chemistry – A European Journal in 2022.HPLC of Formula: 91-02-1 This article mentions the following:

The formal enantioselective umpolung addition of dialkyl phosphites to 2-azaaryl ketones was developed under Broensted base catalysis. The reaction involved the enantioselective protonation of the transient 婵?oxygenated (2-azaaryl)methyl anion generated through the 1,2-addition of the anion of dialkyl phosphite to the 2-azaaryl ketone and the subsequent [1,2]-phospha-Brook rearrangement. A chiral bis(guanidino)iminophosphorane organosuperbase efficiently catalyzed the reaction to provide enantio-enriched phosphates in high yields with good to high enantioselectivities. This is a rare example of the catalytic enantioselective protonation of transient carbanions other than enolates, constructing a trisubstituted stereogenic center 婵?to 2-azaarenes. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1HPLC of Formula: 91-02-1).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ闁荤姾娅ｅΛ纭俵闂? in pyridine vs. 150 kJ闁荤姾娅ｅΛ纭俵闂? in benzene). Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C闂備胶鍋ㄩ崕鎻掝嚕?in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.HPLC of Formula: 91-02-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem