Month: January 2023

Synthesis of Enantioenriched 2-Alkyl Piperidine Derivatives through Asymmetric Reduction of Pyridinium Salts was written by Qu, Bo;Mangunuru, Hari P. R.;Wei, Xudong;Fandrick, Keith R.;Desrosiers, Jean-Nicolas;Sieber, Joshua D.;Kurouski, Dmitry;Haddad, Nizar;Samankumara, Lalith P.;Lee, Heewon;Savoie, Jolaine;Ma, Shengli;Grinberg, Nelu;Sarvestani, Max;Yee, Nathan K.;Song, Jinhua J.;Senanayake, Chris H.. And the article was included in Organic Letters in 2016.COA of Formula: C8H11N This article mentions the following:

In the presence of [Ir(cod)Cl]₂, nonracemic pyridinylbenzoxaphosphole MeO-BoQPhos I, and I₂ in THF, N-benzyl-2-alkylpyridinium bromides such as II•Br^– underwent enantioselective hydrogenation to yield nonracemic N-benzyl-2-alkylpiperidines such as III in 80-95% yields and in 78:22-93:7 er; a perhydroindole and a cis-2,3-dimethylpiperidine were prepared in >99.5:0.5 dr from the corresponding benzylpyridinium bromides. Transition state structures and intermediate energies for a potential mechanism for the hydrogenation were determined using DFT calculations Three of the nonracemic piperidines were converted to fused piperidines such as IV•HCl. The structures of an iridium complex of I and of a hexahydrobenzoquinolizine hydrochloride salt were determined by X-ray crystallog. 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 dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol� in pyridine vs. 150 kJ·mol� in benzene). 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.COA of Formula: C8H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Quinazolinone fungal efflux pump inhibitors. Part 2: In vitro structure-activity relationships of (N-methylpiperazinyl)-containing derivatives was written by Watkins, William J.;Lemoine, Remy C.;Chong, Lee;Cho, Aesop;Renau, Thomas E.;Kuo, Bonnie;Wong, Vickie;Ludwikow, Maria;Garizi, Negar;Iqbal, Nadeem;Barnard, John;Jankowska, Renata;Singh, Rajeshwar;Madsen, Deidre;Lolans, Karen;Lomovskaya, Olga;Oza, Uma;Dudley, Michael N.. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2004.Category: pyridine-derivatives This article mentions the following:

Structure-activity relationships of a novel series of fungal efflux pump inhibitors with respect to potentiation of the activity of fluconazole against strains of Candida albicans and Candida glabrata over-expressing ABC-type efflux pumps are systematically explored. In the experiment, the researchers used many compounds, for example, 3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3Category: pyridine-derivatives).

3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of âˆ?8.7 × 10âˆ? cm3·molâˆ?.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·molâˆ? in the liquid phase and 140.4 kJ·molâˆ? in the gas phase. 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.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis and biological screening of some new 2,5-disubstituted 1,3,4-oxadiazoles was written by Hemavathi, S. N.;Vishu Kumar, B. K.;Lokanatha Rai, K. M.. And the article was included in International Journal of Pharmacy and Pharmaceutical Sciences in 2011.Computed Properties of C12H8N4O This article mentions the following:

The emergence of bactericide resistance and fungicide resistance towards existing antimicrobial agents is one of the major motives for research and development of new mols. to defend them. Substituted 1,3,4-oxadiazoles are of considerable pharmaceutical and material interest, which is documented by a steadily increasing number of publications and patents. 1,3,4-Oxadiazoles show various biol. activities and have been synthesized from different compounds Research on 1,3,4-oxadiazole and their synthetic analogs have revealed a variety of pharmacol. activities including anti-microbial, anti-tubercular and insecticidal agents. Some of these compounds also display activity as analgesics, antiinflammatory agents, anticancer agents, anti-HIV agents, anti-Parkinson agents and anti-proliferate agents. The authors report novel derivatives of the title compounds and their evaluation as antibacterial agents and antifungal agents. Several 2,5-disubstituted 1,3,4-oxadiazole derivatives were prepared which contain pyridine or piperidine rings. The structure of synthesized compounds were confirmed by spectroscopic data, elemental anal. and the target compounds thus formed included 2-[5-(3-piperidinyl)-1,3,4-oxadiazol-2-yl]-1H-indole, 2-(3-piperidinyl)-5-(4-pyridinyl)-1,3,4-oxadiazole, 2-methoxy-4-[5-(4-pyridinyl)-1,3,4-oxadiazol-2-yl]phenol, etc. All compounds were screened for their antimicrobial activity. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Computed Properties of C12H8N4O).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) 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. 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 C12H8N4O

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

A General Palladium-Catalyzed Method for Alkylation of Heteroarenes Using Secondary and Tertiary Alkyl Halides was written by Wu, Xiaojin;See, Jessica Wei Ting;Xu, Kai;Hirao, Hajime;Roger, Julien;Hierso, Jean-Cyrille;Zhou, Jianrong. And the article was included in Angewandte Chemie, International Edition in 2014.Category: pyridine-derivatives This article mentions the following:

A general alkylation of heterocycles using a simple palladium catalyst is reported. Most classes of heterocycles, including indoles and pyridines, efficiently coupled with unactivated secondary and tertiary alkyl halides. An alkyl radical addition to neutral heteroarenes is most likely involved. In the experiment, the researchers used many compounds, for example, 2-Fluoroisonicotinonitrile (cas: 3939-14-8Category: pyridine-derivatives).

2-Fluoroisonicotinonitrile (cas: 3939-14-8) 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. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Photochemistry of aromatic N-oxides. Photochemical behavior of monosubstituted pyridine N-oxides in water solution was written by Bellamy, Francois;Streith, Jacques;Fritz, Hans. And the article was included in Nouveau Journal de Chimie in 1979.Reference of 51834-97-0 This article mentions the following:

The photolysis of monosubstituted pyridine N-oxides gives complex reaction mixtures, most of which contain pyrroles in low yields. The ring contraction is explained by the intermediacy of conjugated nitrenes. In the experiment, the researchers used many compounds, for example, 5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0Reference of 51834-97-0).

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. 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. Reference of 51834-97-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Radical Hydroarylation of Functionalized Olefins and Mechanistic Investigation of Photocatalytic Pyridyl Radical Reactions was written by Seath, Ciaran P.;Vogt, David B.;Xu, Zihao;Boyington, Allyson J.;Jui, Nathan T.. And the article was included in Journal of the American Chemical Society in 2018.Reference of 257937-08-9 This article mentions the following:

We report the photoredox alkylation of halopyridines using functionalized alkene and alkyne building blocks. Selective single-electron reduction of the halogenated pyridines provides the corresponding heteroaryl radicals, which undergo anti-Markovnikov addition to the alkene substrates. The system is shown to be mild and tolerant of a variety of alkene and alkyne subtypes. A combination of computational and exptl. studies support a mechanism involving proton-coupled electron transfer followed by medium-dependent alkene addition and rapid hydrogen atom transfer mediated by a polarity-reversal catalyst. In the experiment, the researchers used many compounds, for example, tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9Reference of 257937-08-9).

tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9) 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Reference of 257937-08-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Oxidative cross-coupling of pyridine N-oxides and ethers between C(sp²)-H/C(sp³)-H bonds under transition-metal-free conditions was written by Sun, Wei;Xie, Zuguang;Liu, Jie;Wang, Lei. And the article was included in Organic & Biomolecular Chemistry in 2015.Application In Synthesis of 3,5-Dimethylpyridine 1-oxide This article mentions the following:

A novel and efficient method based on the cross-coupling reactions of pyridine N-oxides with ethers between C(sp²)-H/C(sp³)-H bonds in the presence of TBHP was developed. The strategy provides an alternative approach to the pyridine moiety under transition-metal-free conditions. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Application In Synthesis of 3,5-Dimethylpyridine 1-oxide).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) 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.Application In Synthesis of 3,5-Dimethylpyridine 1-oxide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

A fast and highly efficient one-pot synthesis of novel isoxazolyl pyrido[2,3-b][1,4]oxazin-2(3H)-ones via Smiles rearrangement using task-specific ionic liquid [HMIm]BF₄ as green solvent was written by Reddy, Modugu Nagi;Kumar, Pittala Praveen;Rajanarendar, Eligeti. And the article was included in Green Chemistry Letters and Reviews in 2017.Safety of 2-Chloro-5-fluoropyridin-3-ol This article mentions the following:

A facile and convenient procedure for the synthesis of isoxazolyl pyrido[2,3-b][1,4]oxazin-2(3H)-ones I (R = 5-methylisoxazol-3-yl, 3,5-dimethylisoxazol-4-yl, 3-methyl-5-styrylisoxazol-4-yl; R¹ = H, Me; X = H, F, Cl, Br) via Smiles rearrangement from isoxazol amines, chloroacetyl chlorides and 2-chloro-3-hydroxypyridines using [HMIm]BF₄ as task-specific ionic liquid has been described. The protocol proves to be efficient and environmentally benign in terms of high yields, eco-friendly solvent, ease of recovery, and reusability of reaction medium. In the experiment, the researchers used many compounds, for example, 2-Chloro-5-fluoropyridin-3-ol (cas: 884494-35-3Safety of 2-Chloro-5-fluoropyridin-3-ol).

2-Chloro-5-fluoropyridin-3-ol (cas: 884494-35-3) 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. 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. Safety of 2-Chloro-5-fluoropyridin-3-ol

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Anomeric Stereoauxiliary Cleavage of the C-N Bond of D-Glucosamine for the Preparation of Imidazo[1,5-a]pyridines was written by Zeng, Kui;Ye, Jin;Meng, Xintong;Dechert, Sebastian;Simon, Martin;Gong, Shuaiyu;Mata, Ricardo A.;Zhang, Kai. And the article was included in Chemistry – A European Journal in 2022.SDS of cas: 91-02-1 This article mentions the following:

An anomeric stereoauxiliary approach for the synthesis of a wide range of imidazo[1,5-a]pyridines I (R¹ = Me, 2-methylphenyl, pyridin-2-yl, etc.; R² = 4-methoxyphenyl, naphthalen-1-yl, thiophen-2-yl, etc.) after cleaving the C-N bond of D-glucosamine (α-2° amine) from biobased resources was reported . This new approach expands the scope of readily accessible imidazo[1,5-a]pyridines I relative to existing state-of-the-art methods. A key strategic advantage of this approach is that the α-anomer of D-glucosamine enables C-N bond cleavage via a seven-membered ring transition state. By using this novel method, a series of imidazo[1,5-a]pyridine derivatives (>80 examples) was synthesized from 2-acylpyridines (including para-dipyridine ketone) and aldehydes (including para-dialdehyde) R²CHO. Imidazo[1,5-a]pyridine I derivatives containing diverse important deuterated C(sp²)-H and C(sp³)-H bonds were also efficiently achieved. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1SDS of cas: 91-02-1).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) 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 groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.SDS of cas: 91-02-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Direct synthesis of carbamate from CO₂ using a task-specific ionic liquid catalyst was written by Zhang, Qiao;Yuan, Hao-Yu;Fukaya, Norihisa;Yasuda, Hiroyuki;Choi, Jun-Chul. And the article was included in Green Chemistry in 2017.Quality Control of Pyridinehydrochloride This article mentions the following:

A superbase-derived protic ionic liquid (IL, [DBUH][OAc]) catalyst was used to directly synthesize carbamate from an amine, CO₂, and a silicate ester. This IL catalyst was easily prepared using its precursors, DBU, and acetic acid. Using 10 mol% of the catalyst under a CO₂ pressure of 5 MPa in acetonitrile at 150 °C, carbamate was isolated in up to 96% yield. Specifically, aliphatic and aromatic amines were activated even though aromatic amines exhibited low activities because of their low pK_a values. Other functional groups in amines were barely activated, affording exclusive chemoselectivity for amine activation. Isotope labeling experiments indicated that the proton in the counter cation is crucial in the catalytic cycle to produce water. In addition, a chem. shift corresponding to a mixture of aniline and [DBUH][OAc] was observed in the ¹H NMR spectrum, related to the formation of hydrogen bonds between aniline and basic acetate anions. The exptl. results indicated that the designed IL catalysts require a protonated cation and a basic anion. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Quality Control of Pyridinehydrochloride).

Pyridinehydrochloride (cas: 628-13-7) 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. Quality Control of Pyridinehydrochloride

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem