Tag: 100-200

Rhodium(III)-catalyzed diverse [4+1] annulation of arenes with 1,3-enynes via sp³/sp² C-H activation and 1,4-rhodium migration was written by Bai, Dachang;Xia, Jintao;Song, Fangfang;Li, Xueyan;Liu, Bingxian;Liu, Lihong;Zheng, Guangfan;Yang, Xifa;Sun, Jiaqiong;Li, Xingwei. And the article was included in Chemical Science in 2019.Application of 4373-61-9 This article mentions the following:

Rhodium(III)-catalyzed sp² and sp³ C-H activation-oxidative annulations between aromatic substrates and 1,3-enynes, where alkenyl-to-allyl 1,4-rhodium(III) migration enabled the generation of electrophilic rhodium(III) π-allyls via remote C-H functionalization are described. Subsequent nucleophilic trapping of these species by various sp²-hybridized N-nucleophiles delivered three classes (external salts, inner salts, and neutral azacycles) of five-membered azacycles bearing a tetrasubstituted saturated carbon center, as a result of [4+1] annulation with the alkyne being a one-carbon synthon. All the reactions proceeded under relatively mild conditions with broad substrate scope, high efficiency, and excellent regioselectivity. The synthetic applications of this protocol have also been demonstrated, and exptl. studies have been performed to support the proposed mechanism. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Application of 4373-61-9).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Facile synthesis of 4-substituted pyridines using Grignard reagents was written by Akiba, Kinya;Iseki, Yuji;Wada, Makoto. And the article was included in Tetrahedron Letters in 1982.Quality Control of 4-Hexylpyridine This article mentions the following:

Reaction of N-(tert-butyldimethylsilyl)pyridinium triflate (I) with Grignard reagents gave 4-substituted 1,4-dihydropyridine derivatives with ≳99% regioselectivity; on oxidation with O these readily gave 4-substituted pyridines in 58-70% yield. E.g., treatment of I with BuMgBr in THF at room temperature under N for 2-3 h followed by bubbling O through the mixture gave 79% 4-butylpyridine. In the experiment, the researchers used many compounds, for example, 4-Hexylpyridine (cas: 27876-24-0Quality Control of 4-Hexylpyridine).

4-Hexylpyridine (cas: 27876-24-0) 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 4-Hexylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Reaction of aromatic N-oxides with dipolarophiles. XV. Formation of the 1,5-sigmatropy products and their double ene reaction products was written by Matsuoka, Toshikazu;Ono, Kikuma;Harano, Kazunobu;Hisano, Takuzo. And the article was included in Chemical & Pharmaceutical Bulletin in 1991.Related Products of 3718-65-8 This article mentions the following:

The pericyclic reaction of 3,5-dimethylpyridine N-oxide with maleimides I ( R = Bu, Ph, substituted Ph) gave furopyridine cycloadducts II formed by the 1,5-sigmatropic rearrangement of the primary exo-cycloadducts. The mol. structure of II (R = Bu) was determined the by the x-ray crystallog. method. In the reaction of 2-alkylpyridine N-oxides III ( R¹ = 3-, 5-Me, 5-Et) with N-substituted maleimides, a series of 1:3 ene reaction products of the type IV (R = Ph, substituted Ph, Bu) were obtained. The primary exo-cycloadducts readily transform into the endo-1,5-sigmatropic rearrangement products, which again react with two mols. of N-substituted maleimide to give the 1:3 ene reaction products. The observed reaction behavior and plausible reaction pathways are discussed in terms of frontier MO considerations. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Related Products of 3718-65-8).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) 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 3718-65-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Screening for emphysema via exhaled volatile organic compounds was written by Cristescu, S. M.;Gietema, H. A.;Blanchet, L.;Kruitwagen, C. L. J. J.;Munnik, P.;van Klaveren, R. J.;Lammers, J. W. J.;Buydens, L.;Harren, F. J. M.;Zanen, P.. And the article was included in Journal of Breath Research in 2011.COA of Formula: C8H11N This article mentions the following:

Chronic obstructive pulmonary disease (COPD)/emphysema risk groups are well defined and screening allows for early identification of disease. The capability of exhaled volatile organic compounds (VOCs) to detect emphysema, as found by computed tomog. (CT) in current and former heavy smokers participating in a lung cancer screening trial, was investigated. CT scans, pulmonary function tests and breath sample collections were obtained from 204 subjects. Breath samples were analyzed with a proton-transfer reaction mass spectrometer (PTR-MS) to obtain VOC profiles listed as ions at various mass-to-charge ratios (m/z). Using bootstrapped stepwise forward logistic regression, we identified specific breath profiles as a potential tool for the diagnosis of emphysema, of airflow limitation or gas-exchange impairment. A marker for emphysema was found at m/z 87 (tentatively attributed to 2-methylbutanal). The area under the receiver operating characteristic curve (ROC) of this marker to diagnose emphysema was 0.588 (95% CI 0.453-0.662). Mass-to-charge ratios m/z 52 (most likely chloramine) and m/z 135 (alkyl benzene) were linked to obstructive disease and m/z 122 (most probably alkyl homologs) to an impaired diffusion capacity. ROC areas were 0.646 (95% CI 0.562-0.730) and 0.671 (95% CI 0.524-0.710), resp. In the screening setting, exhaled VOCs measured by PTR-MS constitute weak markers for emphysema, pulmonary obstruction and impaired diffusion capacity. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4COA of Formula: C8H11N).

2-Isopropylpyridine (cas: 644-98-4) 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.COA of Formula: C8H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Discovery of 2-pyridineformamide thiosemicarbazones as potent antiausterity agents was written by Shakya, Bhushan;Yadav, Paras Nath;Ueda, Jun-ya;Awale, Suresh. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2014.Recommanded Product: 4-Methylpicolinonitrile This article mentions the following:

Series of 2-pyridineformamide thiosemicarbazones I [R¹R² = pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, etc.; R³ = H, 4-Me] were synthesized. Their preferential cytotoxicity in nutrient deprived medium (NDM) was evaluated using PANC-1 human pancreatic cancer cells by employing an antiausterity strategy. 2-Pyridineformamide thiosemicarbazones induced apoptosis and exhibited preferential cytotoxic activity toward PANC-1 cells in NDM, with potencies in the submicromolar range. These compounds are potential candidates for the development of therapeutics against pancreatic cancer. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Recommanded Product: 4-Methylpicolinonitrile).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Equilibrium acidities and homolytic bond dissociation energies of the acidic carbon-hydrogen bonds in N-substituted trimethylammonium and pyridinium cations was written by Zhang, Xian Man;Bordwell, Frederick G.;Van Der Puy, Michael;Fried, Herbert E.. And the article was included in Journal of Organic Chemistry in 1993.Related Products of 17281-59-3 This article mentions the following:

Equilibrium acidities (pK_HA) of the cations in 16 N-substituted trimethylammonium salts, one N-phenacylquinuclidinium salt, 8 N-substituted pyridinium salts, and N-(ethoxycarbonyl)isoquinolinium bromide, together with the oxidation potentials of their conjugate bases, have been determined in Me₂SO. The acidifying effects of the α-trimethylammonium groups (α-Me₃N⁺) and the α-pyridinium groups (α-PyN⁺) on the adjacent acidic C-H bonds in these cations were found to average about 10 and 18 pK_HA units, resp. The homolytic bond dissociation energies of the acidic C-H bonds in these cations, estimated by the combination of the equilibrium acidities with the oxidation potentials of their corresponding conjugate bases (ylides), show that the α-trimethylammonium groups destabilize adjacent radicals by 2-6 kcal/mol, whereas α-pyridinium groups stabilize adjacent radicals by 3-6 kcal/mol. The effects of α-pyridinium groups on the stabilization energies of the radicals derived from these cations were ca. 4-10 kcal/mol smaller than those of the corresponding Ph groups, whereas their effects on the equilibrium acidities of the cations were 5.4-13.1 pK_HA units larger. The pK_HA value of tetramethylammonium cation (Me₄N⁺) was estimated by extrapolation to be about 42 in Me₂SO. In the experiment, the researchers used many compounds, for example, 1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3Related Products of 17281-59-3).

1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. 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. Related Products of 17281-59-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The hypoglycemic effect of (7R^*,9aS^*)-7-phenyl-octahydroquinolizin-2-one in mice was written by Kubo, Hajime;Kobayashi, Junji;Higashiyama, Kimio;Kamei, Junzo;Fujii, Yuji;Ohmiya, Shigeru. And the article was included in Biological & Pharmaceutical Bulletin in 2000.Safety of 4-Methoxy-2-methylpyridine This article mentions the following:

(-)-Multiflorine, which was isolated from leguminous plants, produced a hypoglycemic effect when administered to mice with streptozotocin-induced diabetes. (-)-Multiflorine has an enaminone type conjugation on the A-ring, which is unusual in lupine alkaloids. Proceeding on the assumption that the A-B ring is responsible for the activity, several compounds bearing quinolizidin-2-one were synthesized and their hypoglycemic effects were examined The hypoglycemic effect of (7R^*,9aS^*)-7-phenyl-octahydroquinolizin-2-one was approx. 4 times stronger than that of (-)-multiflorine measured by oral glucose tolerance test in normal mice. This result indicates that compounds possessing the quinolizidin-2-one ring system as the basic structure may be possible lead compounds for a new type of diabetes drug. In the experiment, the researchers used many compounds, for example, 4-Methoxy-2-methylpyridine (cas: 24103-75-1Safety of 4-Methoxy-2-methylpyridine).

4-Methoxy-2-methylpyridine (cas: 24103-75-1) 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Safety of 4-Methoxy-2-methylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Regioselective synthesis and biological evaluation of N-substituted 2-aminoquinazolin-4-ones was written by Liao, Zhen-Yuan;Yeh, Wen-Hsiung;Liao, Pen-Yuan;Liu, Yu-Ting;Chen, Ying-Cheng;Chen, Yi-Hung;Hsieh, Tsung-Han;Lin, Chia-Chi;Lu, Ming-Hsuan;Chen, Yi-Song;Hsu, Ming-Chih;Li, Tsai-Kun;Chien, Tun-Cheng. And the article was included in Organic & Biomolecular Chemistry in 2018.Related Products of 628-13-7 This article mentions the following:

The reaction of Me anthranilates 2-NH₂-R¹-C₆H₃C(O)OCH₃ (R¹ = 5-Cl, 4,5-(OCH₃)₂, 5-OCH₃, 5-Br) with N-arylcyanamides R²NHCN (R² = C₆H₅, 4-H₃CC₆H₄, (CH₂)₂CH₃, etc.) in the presence of p-TsOH in t-BuOH under reflux afforded predominantly 3-arylquinazolin-4-ones I (R³ = H, 6-Cl, 6,7-(OCH₃)₂, 6-OCH₃, 6-Br). In contrast, the reaction of the same reactants with TMSCl in t-BuOH at 60 °C followed by the Dimroth rearrangement in aqueous ethanolic sodium hydroxide gave exclusively the regioisomers, 2-(N-arylamino)quinazolin-4-ones II. The regioselective synthesis of N-aryl-substituted 2-aminoquinazolin-4-ones I (R² = 2-bromophenyl, 2-bromo-4-methylphenyl, 2-bromo-4-fluorophenyl), II can be further applied to the synthesis of benzimidazo[2,1-b]quinazolin-12-ones III (R⁴ = H, CH₃, F) and IV. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Related Products of 628-13-7).

Pyridinehydrochloride (cas: 628-13-7) 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 groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Related Products of 628-13-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Aromatic C-H Methylation and Other Functionalizations via Rh(III)-Catalyzed Migratory Insertion of Bis(phenylsulfonyl)carbene and Subsequent Transformations was written by Chen, Lei;Peng, Rui-jun;Zhang, Xue-jing;Yan, Ming;Chan, Albert S. C.. And the article was included in Journal of Organic Chemistry in 2021.Quality Control of 2-(m-Tolyl)pyridine This article mentions the following:

A Rh(III)-catalyzed migratory insertion of bis(phenylsulfonyl)carbene into aromatic C-H bonds has been developed. A variety of bis(phenylsulfonyl)methyl derivatives e.g., I were prepared with good yields under mild conditions. The methylated products e.g., II were readily obtained after reductive desulfonylation. Furthermore, the diverse transformations of bis(phenylsulfonyl)methyl to other functional groups III (R = trideuteriomethyl, formyl, Et, etc.) were demonstrated. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Quality Control of 2-(m-Tolyl)pyridine).

2-(m-Tolyl)pyridine (cas: 4373-61-9) 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. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Quality Control of 2-(m-Tolyl)pyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis of Molybdenum and Tungsten Alkylidene Complexes that Contain a tert-Butylimido Ligand was written by Jeong, Hyangsoo;Schrock, Richard R.;Muller, Peter. And the article was included in Organometallics in 2015.Synthetic Route of C5H6ClN This article mentions the following:

A variety of Mo or W complexes that contain a tert-butylimido ligand were prepared For example, the o-methoxybenzylidene complex W(N-t-Bu)(CH-o-MeOC₆H₄)(Cl)₂(py) was prepared through addition of pyridinium chloride to W(N-t-Bu)₂(CH₂-o-MeOC₆H₄)₂, while Mo(N-t-Bu)(CH-o-MeOC₆H₄)(OR_F)₂(t-BuNH₂) complexes (OR_F = OC₆F₅ or OC(CF₃)₃) were prepared through addition of two equivalent of R_FOH to Mo(N-t-Bu)₂(CH₂-o-MeOC₆H₄)₂. An x-ray crystallog. study of Mo(N-t-Bu)(CH-o-MeOC₆H₄)[OC(CF₃)₃]₂(t-BuNH₂) showed that the methoxy O is bound to the metal and that two protons on the tert-butylamine ligand are only a short distance away from one of the CF₃ groups on one of the perfluoro-tert-butoxide ligands (H···F = 2.456(17) and 2.467(17) Å). Other synthesized W tert-butylimido complexes include W(N-t-Bu)(CH-o-MeOC₆H₄)(pyr)₂(2,2′-bipyridine) (pyr = pyrrolide), W(N-t-Bu)(CH-o-MeOC₆H₄)(pyr)(OHMT) (OHMT = O-2,6-(mesityl)₂C₆H₃), W(N-t-Bu)(CH-t-Bu)(OHMT)(Cl)(py) (py = pyridine), W(N-t-Bu)(CH-t-Bu)(OHMT)(Cl), W(N-t-Bu)(CH-t-Bu)(pyr)(ODFT)(py), W(N-t-Bu)(CH-t-Bu)(OHMT)₂, and W(N-t-Bu)(CH-t-Bu)(ODFT)₂(ODFT = O-2,6-(C₆F₅)₂C₆H₃). W(N-t-Bu)(CH-t-Bu)(OHMT)₂ does not react with ethylene or 2,3-dicarbomethoxynorbornadiene. Removal of pyridine from W(N-t-Bu)(CH-t-Bu)(Biphen_CF3)(pyridine) (Biphen_CF3 = 3,3′-di-tert-butyl-5,5′-bistrifluoromethyl-6,6′-dimethyl-1,1′-biphenyl-2,2′-diolate) with B(C₆F₅)₃ gave a five-coordinate 14e neopentyl complex as a consequence of CH activation in one of the Me groups in one tert-Bu group of the Biphen_CF3 ligand, as was proven in an x-ray study. An attempted synthesis of W(N-t-Bu)(CH-t-Bu)(Biphen_Me) (Biphen_Me = 3,3′-di-tert-butyl-5,5′,6,6′-tetramethyl-1,1′-biphenyl-2,2′-diolate) gave a 1:1 mixture of W(N-t-Bu)(CH-t-Bu)(Biphen_Me) and a neopentyl complex analogous to the one characterized through an x-ray study. The metallacyclobutane complexes W(N-t-Bu)(C₃H₆)(pyrrolide)(ODFT) and W(N-t-Bu)(C₃H₆)(ODFT)₂ were prepared in reactions involving W(N-t-Bu)(CH-t-Bu)(pyr)₂(bipy), ZnCl₂(dioxane), and one or two equivalent of DFTOH, resp., under 1 atm of ethylene. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Synthetic Route of C5H6ClN).

Pyridinehydrochloride (cas: 628-13-7) 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. 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.Synthetic Route of C5H6ClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem