Tag: 100-200

Re^I-Catalyzed highly regio- and stereoselective C-H addition to terminal and internal alkynes was written by Chang, Yu-Che;Prakash, Sekar;Cheng, Chien-Hong. And the article was included in Organic Chemistry Frontiers in 2019.Application In Synthesis of 2-(m-Tolyl)pyridine This article mentions the following:

An effective ortho C-H functionalization of arylpyridines e.g., I and detachable N-pyrimidyl indoles II (R = H, CH₃, C(O)CH₃) by terminal and internal alkynes R¹CCR² (R¹ = H, C₆H₅, CH₃(CH₂)₂, C₆H₅CC; R² = 4-CH₃C₆H₄, (CH₂)₅OH, cyclohexyl, etc.) using a Re(I) catalyst providing an efficient access to various E-selective alkenylation products e.g., III were developed. The catalytic reaction is compatible with various aliphatic alkynes, aromatic terminal alkynes and internal alkynes, and structurally different nitrogen heterocycles. Deuterium-labeling experiments indicate that significant deuterium scrambling occurs with the directing groups and acetylenic sp C-H bonds before the migratory insertion. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Application In Synthesis of 2-(m-Tolyl)pyridine).

2-(m-Tolyl)pyridine (cas: 4373-61-9) 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. 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 2-(m-Tolyl)pyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Analysis of nitrogenous organic compounds from mainstream cigarette smoke using low-temperature solvent extraction followed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry was written by Xiang, Zhangmin;Cai, Kai;Zhou, Shuping;Geng, Zhaoliang;Pan, Wenjie. And the article was included in Journal of Separation Science in 2015.Recommanded Product: 2-Isopropylpyridine This article mentions the following:

A method involving comprehensive two-dimensional gas chromatog. coupled to high-resolution time-of-flight mass spectrometry was developed and applied to the anal. of nitrogenous organic compounds present in mainstream cigarette smoke trapped on self-designed equipment. The samples were prepared using low-temperature solvent extraction under liquid nitrogen and analyzed by comprehensive two-dimensional gas chromatog. with high-resolution time-of-flight mass spectrometry. Important exptl. parameters, such as the type and volume of the extraction solvent and flow rate of smoking, were optimized to improve the anal. parameter. The results indicated that 180 mL of di-Et ether in the low-temperature solvent extraction apparatus system with a 4 mL/min smoke flow rate were the optimal conditions. Then, 85 nitrogenous organic compounds were identified and quantified using a mass spectral library search, accurate mass ion and N-rules of a mol. formula for nitrogen compounds Finally, a comparison of the low temperature solvent extraction and Cambridge filter pad method indicated that more peaks, a higher peak volume and better repeatability were obtained using the low-temperature solvent extraction method. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Recommanded Product: 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Recommanded Product: 2-Isopropylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The Impact of the Interplay between Steric and Electronic Effects on the Synthesis and Optical Properties of Diketopyrrolopyrroles Bearing Pyridine Moieties was written by Vakuliuk, Olena;Purc, Anna;Clermont, Guillaume;Blanchard-Desce, Mireille;Gryko, Daniel T.. And the article was included in ChemPhotoChem in 2017.Related Products of 3939-12-6 This article mentions the following:

The influence of a combination of steric and electronic factors on both the preparation and the optical properties of diketopyrrolopyrroles was investigated. The attachment of a cyano group to the electron-deficient pyridine ring overcame the neg. influence of the flanking Me group on the efficiency of the synthesis of diketopyrrolopyrroles. Diketopyrrolopyrroles possessing pyridine-N-oxide moieties were studied for the first time. We have also shown that reactions of cyanopyridines possessing an addnl. dialkylamino group were very capricious and depending on the relative position of all substituents, can lead to low yields of diketopyrrolopyrroles. The interplay between the dihedral angle between the diketopyrrolopyrrole core and the pyridyl substituents as well as the presence and position of electron-donating moieties made it possible to modulate the photophys. properties of N,N’-dialkyldiketopyrrolopyrroles. In particular, it was found that pyridine-N-oxides as the aryl moieties had a strong influence on the optical properties of diketopyrrolopyrroles, shifting both absorption and emission bands bathochromically. Two-photon absorption cross-sections had low values except for those dyes possessing a clear quadrupolar centrosym. nature. In the experiment, the researchers used many compounds, for example, 6-Fluoronicotinonitrile (cas: 3939-12-6Related Products of 3939-12-6).

6-Fluoronicotinonitrile (cas: 3939-12-6) 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.Related Products of 3939-12-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Trimethylsilanol as a leaving group; III. A simple one-step conversion of aromatic heterocyclic N-oxides to α-cyano aromatic N-heterocycles was written by Vorbrueggen, Helmut;Krolikiewicz, Konrad. And the article was included in Synthesis in 1983.Recommanded Product: 1620-76-4 This article mentions the following:

Heterocyclic N-oxides such as pyridine or quinoline N-oxides were treated with Me₃SiCN in the presence of Et₃N in MeCN to give α-cyano heterocycles. The strong affinity of the hard Me₃Si group for the hard N-oxide moiety and the soft CN group for the adjacent soft α-C atom was apparently the driving force for the selective α-addition of Me₃SiCN to the heterocyclic N-oxide, followed by elimination of Me₃SiOH as a leaving group. Thus, pyridine N-oxide added Me₃SiCN to give 80% 2-cyanopyridine. Among the ∼10 other compounds similarly prepared were 2-cyano-4-methylpyridine, 2-cyano-3-hydroxypyridine and 2-cyanoquinoline. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Recommanded Product: 1620-76-4).

4-Methylpicolinonitrile (cas: 1620-76-4) 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.Recommanded Product: 1620-76-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis of m-Alkylphenols via a Ruthenium-Catalyzed C-H Bond Functionalization of Phenol Derivatives was written by Li, Gang;Gao, Panpan;Lv, Xulu;Qu, Chen;Yan, Qingkai;Wang, Ya;Yang, Suling;Wang, Junjie. And the article was included in Organic Letters in 2017.Quality Control of 2-Phenoxypyridine This article mentions the following:

In the presence of [RuCl₂(p-cymene)]₂ and 1-adamantanecarboxylic acid, aryl 2-pyridinyl ethers underwent regioselective alkylation with secondary and tertiary alkyl bromides mediated by K₂CO₃ in benzene to provide m-alkylaryl 2-pyridinyl ethers in 33-73% yields; N-methylation of the pyridine moiety with Me triflate followed by hydrolysis yielded m-alkylated phenols such as 3-tert-butylphenol in 74-82% yields. The method was used to prepare the pesticide etoxazole via 3-tert-butylphenol. A (p-cymene)ruthenium complex of 2-phenoxypyridine was prepared and underwent regioselective alkylation to give 3-(3-pentyl)phenyl 2-pyridinyl ether under the standard reaction conditions; addition of TEMPO, BHT, or benzoquinone inhibited the reaction. The structure of the (p-cymene)ruthenium complex of 2-phenoxypyridine was determined by X-ray crystallog. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Quality Control of 2-Phenoxypyridine).

2-Phenoxypyridine (cas: 4783-68-0) 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. Quality Control of 2-Phenoxypyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis of 2,5-thiazole butanoic acids as potent and selective α_vβ₃ integrin receptor antagonists with improved oral pharmacokinetic properties was written by Wendt, John A.;Wu, Hongwei;Stenmark, Heather G.;Boys, Mark L.;Downs, Victoria L.;Penning, Thomas D.;Chen, Barbara B.;Wang, Yaping;Duffin, Tiffany;Finn, Mary Beth;Keene, Jeffery L.;Engleman, V. Wayne;Freeman, Sandra K.;Hanneke, Melanie L.;Shannon, Kristen E.;Nickols, Maureen A.;Steininger, Christina N.;Westlin, Marissa;Klover, Jon A.;Westlin, William;Nickols, G. Allen;Russell, Mark A.. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2006.Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine This article mentions the following:

A series of 2,5-thiazoles, e.g. I [R = 3-FC₆H₄, 3,4-(MeO)₂C₆H₃, 6-methoxy-3-pyridyl, 2-phenyl-5-thiazolyl, etc.], which are potent antagonists of the integrin α_vβ₃ and show selectivity relative to the other integrins, such as α_IIbβ₃ and α_vβ₆, has been synthesized. These analogs were demonstrated to have high bioavailability relative to other relative heterocyclic analogs. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine).

3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2) 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.Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Dual Emission, Aggregation, and Redox Properties of Boron Difluoride Hydrazones Functionalized with Triphenylamines was written by Cappello, Daniela;Buguis, Francis L.;Boyle, Paul D.;Gilroy, Joe B.. And the article was included in ChemPhotoChem in 2022.Application of 91-02-1 This article mentions the following:

π-Conjugated mol. materials often exhibit interesting photoluminescence, redox, and optoelectronic properties that grant them utility as light-harvesting materials in solar cells, as the emissive component of organic light-emitting diodes, and as fluorescence sensors. Preparing dye conjugates by appending multiple dyes together to generate π-conjugated mols. is a common strategy to enhance the properties of these materials as it often imparts traits that cannot be achieved by the building blocks independently. Herein, we report mol. materials that incorporate boron difluoride hydrazone (BODIHY) and triphenylamine (TPA) units that exhibit charge-transfer character, dual-emission, and aggregation-induced emission. The title compounds have low-energy absorption bands (λ_abs=455-493 nm) that are red-shifted relative to BODIHYs with smaller π-systems and exhibit dual-emission in the solution, solid, and aggregate states. TPA-BODIHY (donor-acceptor) conjugates show multiple reversible redox events and, in combination, the data presented herein indicate that there is electronic communication throughout the donor-acceptor and acceptor-donor-acceptor π-systems. These results are rationalized with the use of computational chem. and solid-state structural anal. This study provides new opportunities for the design of mol. materials that are comprised of redox-active photoluminescent dyes, including BODIHY, and their potential applications. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1Application of 91-02-1).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) 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 α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Application of 91-02-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Experimental and theoretical studies on rhodium-catalyzed direct C-H benzoxylation reaction was written by Jin, Chen;Wang, Guimin;Yang, Xueyan;Zhu, Weiliang;Yang, Yaxi. And the article was included in Tetrahedron Letters in 2018.Related Products of 4373-61-9 This article mentions the following:

The green and efficient rhodium-catalyzed, chelation assisted C-H benzoxylation reaction of electron donating group containing benzenes with hydroxy-benziodoxolone was developed to yield mono-oxidation i.e. I [R = H, 3-Me, 4-OMe, etc.; R¹ = 2-pyridyl, 2-pyrimidinyl, 1-pyrazolyl; R² = OC(O)-2-I-C₆H₄] and di-oxidation i.e. II products which released water as the single byproduct. The reaction proceeded under mild conditions with controllable mono- and dioxygenation selectivity. DFT calculations supported the nucleophilic addition pathway was most likely involved in the current reaction system. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Related Products of 4373-61-9).

2-(m-Tolyl)pyridine (cas: 4373-61-9) 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. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Related Products of 4373-61-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Crystallization and Glass-Forming Ability of Ionic Liquids: Novel Insights into Their Thermal Behavior was written by Lobo Ferreira, Ana I. M. C.;Rodrigues, Ana S. M. C.;Villas, Miguel;Tojo, Emilia;Rebelo, Luis Paulo N.;Santos, Luis M. N. B. F.. And the article was included in ACS Sustainable Chemistry & Engineering in 2019.Electric Literature of C11H17N This article mentions the following:

This work presents an extended study of the thermal behavior of the alkyl and dialkylpyridinium derivatives of the bis(trifluoromethylsulfonyl)imide ionic liquid series, using high resolution power compensation differential scanning calorimetry (DSC) equipment. Temperatures, enthalpies, entropies, and the heat capacity change associated with the glass transition, as well as cold crystallization, solid-solid transitions, and melting, are used to evaluate their ability to form a glass and crystallize. The effects of the cation isomerization and the alkyl chain length increase were used to investigate the nature of the irregular thermal behavior of ionic liquids in general and to establish the link between their thermal properties and nanostructuration. The observed V-shape profile of the melting temperatures vs. the alkyl side-chain length is interpreted as a consequence of the balance between the initial decrease of the magnitude of the electrostatic interaction and the regular increase of the dispersive van der Waals forces. The observed differentiation between the thermal behavior below and above the critical alkyl size, CAS, is analyzed and compared with the regular behavior of both the n-alkanes and the n-alkanols. Above the CAS, the entropy and enthalpy profiles present trends similar to those observed in the alkane and alc. series, contrasting with those observed in the molten salts-like region. These results and evidence are a strong support to the interpretation of the effect of the ILs nanostructuration in the phys.-chem. properties. We found a great similarity between the thermal behavior of the imidazolium and pyridinium cation core, highlighting the strong ability of ILs to form a nanostructured network with distinguishable polar and nonpolar domains in the liquid phase. In the experiment, the researchers used many compounds, for example, 4-Hexylpyridine (cas: 27876-24-0Electric Literature of C11H17N).

4-Hexylpyridine (cas: 27876-24-0) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Electric Literature of C11H17N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ion pairing in 1-butyl-3-methylpyridinium halide ionic liquids studied using NMR and DFT calculations was written by Swamy, Vincent P.;Thulasiram, Hirekodathakallu V.;Rastrelli, Federico;Saielli, Giacomo. And the article was included in Physical Chemistry Chemical Physics in 2018.Synthetic Route of C10H16ClN This article mentions the following:

We present the ¹H, ¹³C and ¹⁵N NMR chem. shifts of bulk ionic liquids based on 1-butyl-3-methylimidazolium (the cation also known as 1-butyl-3-picolinium) halides (Cl^–, Br^– and I^–) and tribromide (Br₃^–) salts. A characterization in solution of the analogous ICl₂^– and I₃^– salts is also reported. A series of DFT calculations has been run to predict the features of the NMR spectra of the pure ILs based on a few selected supramol. ionic aggregates. To test the effect of temperature, and vibrational and conformational motions, only for the chloride salt, we also run first-principles mol. dynamics simulations of the ion pair in the gas phase, using the ADMP scheme (Atom Centered D. Matrix Propagation mol. dynamics model). The aim of our investigation is to test whether a simple DFT based approach of ion-pairing in ionic liquids is capable of providing reliable results and under which conditions the protocol is robust. We obtained a very good agreement between the calculated and exptl. spectra for the three halides, where the bulk structure of the ILs is dominated by H-bond interactions between the X^– anion (X = Cl, Br and I) and the ortho protons of the pyridinium ring (a structural arrangement not too different from the solid-state structure of pyridinium halides). In contrast, when the H-bond is weak, as in the Br₃^– case, a number of supramol. arrangements exist in solution and the simple DFT calculations of a few selected cases cannot exhaustively explore the complete energy landscape. Moreover, the dynamic effects due to thermal motion, evaluated by ADMP MD simulations of the chloride salt, appear to be not very significant. In the experiment, the researchers used many compounds, for example, 1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3Synthetic Route of C10H16ClN).

1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3) 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. 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 C10H16ClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem