Tag: 100-200

NMR studies of picolyl-type carbanions. VIII. Anions produced by reactions of alkyl-substituted pyridines with butyllithium was written by Konishi, Kazuyori;Matsumoto, Hiroshi;Saito, Katsuhiro;Takahashi, Kensuke. And the article was included in Bulletin of the Chemical Society of Japan in 1985.Product Details of 644-98-4 This article mentions the following:

¹H and ¹³C NMR spectra are reported for anions produced from methyl-, ethyl- and isopropylpyridines in THF. Two kinds of anions are formed concomitantly by Li-proton exchange and BuLi addition with 2-ethyl-, 2-isopropyl-, 4-methyl- and 4-ethylpyridines. The former reaction tends to occur at the substituent bonded to the position adjacent to N, and the latter occurs at an unsubstituted position adjacent to N. In the anions formed by the exchange from 2- and 4-ethylpyridines, a specific ring proton is coupled to the α-C atom, and, further, the o– or m-protons (or -C atoms) in the latter anion are nonequivalent at room temperature The α-carbons in these anions are virtually sp²-hybridized. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Product Details of 644-98-4).

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. 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.Product Details of 644-98-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Regioselective cyanation of 3-substituted pyridine 1-oxides was written by Fife, Wilmer K.. And the article was included in Heterocycles in 1984.Application of 89809-65-4 This article mentions the following:

N-Oxides I (R = H, Me, OMe, OH, Cl, cyano, CO₂Me) were converted to mixtures of nitriles II and III. I (R = Me) was treated with Me₃SiCN and Me₂NCOCl in CH₂Cl₂ to give 90% II (R = Me) and 10% III (R = Me). In the experiment, the researchers used many compounds, for example, Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4Application of 89809-65-4).

Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Application of 89809-65-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Identification of an Oxalamide Ligand for Copper-Catalyzed C-O Couplings from a Pharmaceutical Compound Library was written by Chan, Vincent S.;Krabbe, Scott W.;Li, Changfeng;Sun, Lijie;Liu, Yue;Nett, Alex J.. And the article was included in ChemCatChem in 2019.Electric Literature of C6H7NO2 This article mentions the following:

The use of pharmaceutical compound library approach in combination with high throughput screening to identify N,N’-bis(thiophene-2-ylmethyl)oxalamide as a ligand that was generally effective for copper-catalyzed C-O cross-couplings to prepare both biarylethers as well as phenols under mild conditions. In the experiment, the researchers used many compounds, for example, 5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0Electric Literature of C6H7NO2).

5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-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 σ bonds. 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.Electric Literature of C6H7NO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ring-Closing Metathesis Reactions: Interpretation of Conversion-Time Data was written by Thiel, Vasco;Wannowius, Klaus-Juergen;Wolff, Christiane;Thiele, Christina M.;Plenio, Herbert. And the article was included in Chemistry – A European Journal in 2013.Reference of 85838-94-4 This article mentions the following:

Conversion-time data were recorded for various ring-closing metathesis (RCM) reactions that lead to five- or six-membered cyclic olefins by using different precatalysts of the Hoveyda type. Slowly activated precatalysts were found to produce more RCM product than rapidly activated complexes, but this comes at the price of slower product formation. A kinetic model for the anal. of the conversion-time data was derived, which is based on the conversion of the precatalyst (Pcat) into the active species (Acat), with the rate constant k_act, followed by two parallel reactions: (1) the catalytic reaction, which utilizes Acat to convert reactants into products, with the rate k_cat, and (2) the conversion of Acat into the inactive species (Dcat), with the rate k_dec. The calculations employ two exptl. parameters: the concentration of the substrate (c(S)) at a given time and the rate of substrate conversion (-dc(S)/dt). This provides a direct measure of the concentration of Acat and enables the calculation of the pseudo-first-order rate constants k_act, k_cat, and k_dec and of k_S (for the RCM conversion of the resp. substrate by Acat). Most of the RCM reactions studied with different precatalysts are characterized by fast k_cat rates and by the k_dec value being greater than the k_act value, which leads to quasistationarity for Acat. The active species formed during the activation step was shown to be the same, regardless of the nature of different Pcats. The decomposition of Acat occurs along two parallel pathways, a unimol. (or pseudo-first-order) reaction and a bimol. reaction involving two ruthenium complexes. Electron-deficient precatalysts display higher rates of catalyst deactivation than their electron-rich relatives. Slowly initiating Pcats act as a reservoir, by generating small stationary concentrations of Acat. Based on this, it can be understood why the use of different precatalysts results in different substrate conversions in olefin metathesis reactions. In the experiment, the researchers used many compounds, for example, tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4Reference of 85838-94-4).

tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-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 σ 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.Reference of 85838-94-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Novel pyridinyl and pyrimidinylcarbazole sulfonamides as antiproliferative agents was written by Hu, Laixing;Li, Zhuo-rong;Wang, Yue-ming;Wu, Yanbin;Jiang, Jian-Dong;Boykin, David W.. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2007.Application In Synthesis of 3-Amino-2,6-dimethoxypyridine This article mentions the following:

A series of azaheterocyclic carbazole sulfonamides was synthesized and evaluated for antiproliferative activity. The most potent compounds N-(2,6-dimethoxypyridin-3-yl)-9-ethyl- and 9-methylcarbazole-3-sulfonamide (I, R = Et, Me) gave significant cytotoxicity (IC₅₀ = 122 and 101 nM). I (R = Et) displayed submicromolar activities against seven human tumor cell lines. The SARs of this series of sulfonamides, which include the influence of azaheterocycle rings, sulfonamide linkage, and the carbazole ring, are described. In the experiment, the researchers used many compounds, for example, 3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3Application In Synthesis of 3-Amino-2,6-dimethoxypyridine).

3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Application In Synthesis of 3-Amino-2,6-dimethoxypyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Rhodium(III)-catalyzed aromatic C-H cyanation with dimethylmalononitrile as a cyanating agent was written by Li, He;Zhang, Sheng;Yu, Xiaoqiang;Feng, Xiujuan;Yamamoto, Yoshinori;Bao, Ming. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2019.Computed Properties of C12H11N This article mentions the following:

A rhodium-catalyzed aromatic C-H bond direct cyanation with safe, bench-stable, and com. available dimethylmalononitrile as the cyanating agent has been successfully developed by using copper oxide as a promotor. Pyridine, quinoline, pyrimidine and pyrazole were used as the directing group in this type of C-H bond direct cyanation reaction. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Computed Properties of C12H11N).

2-(m-Tolyl)pyridine (cas: 4373-61-9) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Computed Properties of C12H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthetic applications of nitrogen-nitrogen linked heterocycles. Part 4. The reaction between 1-pyridinio-4-pyridone cations and cyanide ion: mechanism of cyanopyridine formation, and a regioselective synthesis of 4-cyanopyridines was written by Leung, Christopher W. F.;Sammes, Michael P.;Katritzky, Alan R.. And the article was included in Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) in 1979.Application In Synthesis of 4-Methylpicolinonitrile This article mentions the following:

Treating pyridiniopyridones I (R = H, R¹ = H, alkyl) with aqueous NaCN gave mixtures of 2- and 4-cyanopyridines, favored by high and low CN^– concentrations, resp. Small amounts of 1,4-dihydro-4-cyano adducts were also obtained at low CN^– concentrations E.g., an 8.73:1 ratio of CN^– and I (R = R¹ = H) gave 37% 2-cyanopyridine (II) and 17% 4-cyanopyridine (III), whereas a 2.47:1 ratio of starting materials gave 7% II and 51% III. I (R = Me, R¹ = H, alkyl) gave high yields of 1,4-dihydro-4-cyano adducts. E.g., I (R = Me, R¹ = H) gave 78% IV (R² = H) and IV (R² = Me), the IV mixture decomposed quant. on heating to a mixture of III and 2,6-dimethyl-4-pyridone. 2-Cyanopyridines were probably formed via 1,2-dihydro-2-cyano adducts. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Application In Synthesis of 4-Methylpicolinonitrile).

4-Methylpicolinonitrile (cas: 1620-76-4) 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. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Application In Synthesis of 4-Methylpicolinonitrile

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Effect of substituents on the basicity of pyridines in an apolar medium was written by Laurence, C.;Lucon, M.. And the article was included in Canadian Journal of Chemistry in 1976.Related Products of 4783-68-0 This article mentions the following:

The frequency v(OH…N) of methanol complexes with substituted pyridines appears to be a sensitive detector of substituent effects on the basicity of pyridines in an apolar medium. The coefficients ρI and ρR, which respond to I and R effects and which are obtained from the Taft-Ehrenson equation, agree with those found for the pKa of pyridinium ions for the three substitution positions. Those values which diverge are explained by the much greater electron attracting power of the zonium group compared to that of the aza group. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Related Products of 4783-68-0).

2-Phenoxypyridine (cas: 4783-68-0) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-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 σ bonds. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Related Products of 4783-68-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Density functional study of alkylpyridine-iodine interaction and its implications in the open-circuit photovoltage of dye-sensitized solar cell was written by Kusama, Hitoshi;Sugihara, Hideki. And the article was included in Solar Energy Materials & Solar Cells in 2006.Formula: C8H11N This article mentions the following:

A d. functional theory (DFT) method was used to study the monomer and intermol. charge-transfer complexes of 22 different alkylpyridines with diiodine. DFT calculations revealed that the σ* orbital of iodine interacts with the nitrogen lone pair in pyridines. The open-circuit photovoltage (V_oc) values of a bis(tetrabutylammonium)cis-bis(thiocyanato)bis(2,2′-bipyridine-4-carboxylic acid, 4′-carboxylate)ruthenium(II) (N719) dye-sensitized nanocrystalline TiO₂ solar cell with an I^–/I^–₃ redox electrolyte in acetonitrile using alkylpyridines additive were compared to computational calculations on the interaction between pyridines and I₂ by a DFT method. The optimized geometries, frequency analyses, Mulliken population analyses, and interaction energies suggest that the V_oc value of the solar cell is higher, the more alkylpyridine complexes with I₂. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Formula: C8H11N).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Formula: C8H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Lanthanide-based peptide-directed Vis/NIR imaging and inhibition of LMP1 was written by Chau, Ho-Fai;Wu, Yue;Fok, Wan-Yiu;Thor, Waygen;Cho, William Chi-Shing;Ma, Ping’an;Lin, Jun;Mak, Nai-Ki;Bunzli, Jean-Claude G.;Jiang, Lijun;Long, Nicholas J.;Lung, Hong Lok;Wong, Ka-Leung. And the article was included in JACS Au in 2021.Synthetic Route of C6H6BrNO This article mentions the following:

A lanthanide-based peptide-directed bioprobe LnP19 (Ln = Eu or Yb) is designed as an impressive example of a small mol.-based dual-functional probe for the EBV oncoprotein LMP1. The peptide P19 (Pra-KAhx-K-LDLALK-FWLY-K-IVMSDKW-K-RrRK) is designed to selectively bind to LMP1 by mimicking its TM1 region during oligomerization in lipid rafts while signal transduction is significantly suppressed. Immunofluorescence imaging and Western blotting results reveal that P19 can effectively inactivate the oncogenic cellular pathway nuclear factor κB (NF-κB) and contribute to a selective cytotoxic effect on LMP1-pos. cells. By conjugation with cyclen-based europium(III) and ytterbium(III) complexes, EuP19 and YbP19 were constructed to offer visible and near-IR LMP1-targeted imaging and cancer monitoring. In addition to the ability to target and inhibit LMP1 and to selective inhibit LMP1-pos. cells, the selective growth inhibition toward LMP1-pos. tumor by LnP19 is also demonstrated. In the experiment, the researchers used many compounds, for example, (4-Bromopyridin-2-yl)methanol (cas: 131747-45-0Synthetic Route of C6H6BrNO).

(4-Bromopyridin-2-yl)methanol (cas: 131747-45-0) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. 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 C6H6BrNO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem