Chemistry Of Pyridine Research Articles

Pyridine derivatives as preferable scaffolds for the process of discovering new drugs

The pyridine ring is present in numerous significant plant compounds. It is used as a therapeutic to boost the solubility and bioavailability of less soluble chemicals since it is a polar and ionizable aromatic molecule. Chemical compounds derived from pyridine are highly sought-after in the pharmaceutical industry. An essential synthesis strategy in the search for novel medications is the fusion of the pyridine nucleus. Due to the compounds’ powerful therapeutic characteristics, medicinal chemists have long been fascinated by the chemistry of pyridine and its derivatives, which inspires them to look for and make novel compounds with biological utility. There are significant ramifications for medical chemistry in the adaptability of pyridine and its derivatives as reactants and starting materials for structural changes. Pesticides and agricultural chemicals that heavily rely on pyridine derivatives include insecticides, fungicides, and herbicides; However, this page focuses on their medical applications. Pyridine derivatives are frequently used in the textile industry to create dyes. We present the most recent findings from 2010 onward, highlighting the growing significance of pyridine scaffolds in medicinal chemistry and the development of new drugs. Even though there are a lot of studies on pyridine derivatives, this chapter only has compounds with a clear pharmacophore.

Fingerprinting fragments of fragile interstellar molecules: dissociation chemistry of pyridine and benzonitrile revealed by infrared spectroscopy and theory.

The cationic fragmentation products in the dissociative ionization of pyridine and benzonitrile have been studied by infrared action spectroscopy in a cryogenic ion trap instrument at the Free-Electron Lasers for Infrared eXperiments (FELIX) Laboratory. A comparison of the experimental vibrational fingerprints of the dominant cationic fragments with those from quantum chemical calculations revealed a diversity of molecular fragment structures. The loss of HCN/HNC is shown to be the major fragmentation channel for both pyridine and benzonitrile. Using the determined structures of the cationic fragments, potential energy surfaces have been calculated to elucidate the nature of the neutral fragment partner. In the fragmentation chemistry of pyridine, multiple non-cyclic structures are formed, whereas the fragmentation of benzonitrile dominantly leads to the formation of cyclic structures. Among the fragments are linear cyano-(di)acetylene˙+, methylene-cyclopropene˙+ and o- and m-benzyne˙+ structures, the latter possible building blocks in interstellar polycyclic aromatic hydrocarbon (PAH) formation chemistry. Molecular dynamics simulations using density functional based tight binding (MD/DFTB) were performed and used to benchmark and elucidate the different fragmentation pathways based on the experimentally determined structures. The implications of the difference in fragments observed for pyridine and benzonitrile are discussed in an astrochemical context.

Pyridinic Nanographenes by Novel Precursor Design.

In this work we present the solution‐synthesis of pyridine analogues to hexa‐peri‐hexabenzocoronene (HBC)—which might be called superpyridines—via a novel precursor design. The key step in our strategy was the pre‐formation of the C−C bonds between the 3/3’ positions of the pyridine and the adjacent phenyl rings—bonds that are otherwise unreactive and difficult to close under Scholl‐conditions. Apart from the synthesis of the parent compound we show that classical pyridine chemistry, namely oxidation, N‐alkylation and metal‐coordination is applicable to the π‐extended analogue. Furthermore, we present basic physical chemical characterizations of the newly synthesized molecules. With this novel synthetic strategy, we hope to unlock the pyridine chemistry of nanographenes.

Classification Of Isoxynoline Alkaloides By Structure And Effect

The chemistry of pyridine and its partially or completely hydrogenated analogues, used in various fields, is one of the fastest growing fields of interest for chemists and pharmacologists. Pyridine, pyridine, and tetrahydroisoquinoline rings are the major fragments of many natural and synthetic biologically active substances. Quaternary pyridinium salts are widely used as alkylating agents, interfacial migration catalysts, antiseptics, ionic liquids as surfactants and anticorrosives.

Phototransposition chemistry of pyridine and substituted pyridines in the vapor phase

Phototransposition chemistry of pyridine and substituted pyridines in the vapor phase

Nucleophilic Dearomatization of Activated Pyridines

Amongst nitrogen heterocycles of different ring sizes and oxidation statuses, dihydropyridines (DHP) occupy a prominent role due to their synthetic versatility and occurrence in medicinally relevant compounds. One of the most straightforward synthetic approaches to polysubstituted DHP derivatives is provided by nucleophilic dearomatization of readily assembled pyridines. In this article, we collect and summarize nucleophilic dearomatization reactions of pyridines reported in the literature between 2010 and mid-2018, complementing and updating previous reviews published in the early 2010s dedicated to various aspects of pyridine chemistry. Since functionalization of the pyridine nitrogen, rendering a (transient) pyridinium ion, is usually required to render the pyridine nucleus sufficiently electrophilic to suffer the attack of a nucleophile, the material is organized according to the type of N-functionalization. A variety of nucleophilic species (organometallic reagents, enolates, heteroaromatics, umpoled aldehydes) can be productively engaged in pyridine dearomatization reactions, including catalytic asymmetric implementations, providing useful and efficient synthetic platforms to (enantioenriched) DHPs. Conversely, pyridine nitrogen functionalization can also lead to pyridinium ylides. These dipolar species can undergo a variety of dipolar cycloaddition reactions with electron-poor dipolarophiles, affording polycyclic frameworks and embedding a DHP moiety in their structures.

Multidentate Phosphanyl Phosphinines: Synthesis and Properties.

With respect to the well-developed chemistry of pyridines, that of phosphinines is in its infancy. There are still challenges to be overcome with respect to the development of simple syntheses and the application of phosphinine derivatives. Here, we show that sodium phosphinin-2-olate is a valuable building block to prepare multidentate phosphinine ligands, which in turn can be employed for the preparation of metal complexes. These PdII and RhI complexes were fully characterized, including by NMR spectra and single-crystal X-ray diffraction studies, which clearly demonstrate that molecules R3-x P(O-phosphinine)x with one, two, and three phosphinines (x=1, 2, 3) can be tethered to a central phosphorus donor center to give bis-, tris-, and tetradentate ligands.

Aleksei Yevgen'evich Chichibabin (1871-1945): A Century of Pyridine Chemistry.

Tutor, journalist, patriot, and defector: Aleksei Yevgen'evich Chichibabin made seminal contributions to the chemistry of pyridines. As the Chichibabin reaction enters its second century, it is appropriate to re-examine the life of this remarkable chemist and his legacy to heterocyclic chemistry.

ChemInform Abstract: Synthesis, Transformations and Biological Properties of Furo[2,3‐b]pyridines

AbstractReview: 97 refs.

6-Diphenylphosphinopyridin-2-(1H)-one (6-DPPon)

Among heterocyclic structural units, pyridines are the most prevalent and have attracted the attention of chemists.[1] One important aspect of pyridine chemistry is designing new ligands based on the pyridine core.[2] Inspired by DNA base pairing, 6-DPPon (white solid, mp: 187 °C) was introduced by Bernhard Breit (Albert-Ludwigs-Universität Freiburg) as a monodentate ligand.[3] This compound can not only be easily prepared (Scheme [1]) but also has a brilliant property: the ability for self-assembly.[4]

Pyridine chemistry from Chichibabin's reactions to metal catalysed C-H functionalizations - An overview

Pyridine chemistry from Chichibabin's reactions to metal catalysed C-H functionalizations - An overview

ChemInform Abstract: Anion Receptors Containing Heterocyclic Rings

AbstractReview: 79 refs.

Theoretical studies on the kinetics and reactivity of the gas-phase addition and H-abstraction reactions of methylpyridine with atomic chlorine

The atmospheric chemistry of pyridine and methylpyridine (picoline) are important because of its presence in the atmosphere from industrial sources and also from the coal combustion. Theoretical investigations are carried out on the mechanism, kinetics and thermochemistry for the reaction between methylpyridine [C 5H 4(CH 3)N, picoline] and atomic chlorine (Cl) using the hybrid density functional model BB1K. Thermodynamic and kinetic parameters for addition of Cl to N-atom of picoline as well as to ring carbon sites and hydrogen abstraction reactions from all the potential sites are calculated. This helps to identify the most reactive reaction channels in different temperature range.

ARSENAL AGREES TO BUY DSM UNIT

THE PRIVATE EQUITY company Arsenal Capital Partners has agreed to acquire DSM’s special products business for an undisclosed sum. The purchase continues Arsenal’s push into the chemical business, where it has already created and sold a firm. DSM Special Products’ main site is in Rotterdam, the Netherlands, where it operates the world’s largest plant for oxidizing toluene into benzoic acid, a starting point for the fine chemicals benzaldehyde and benzyl alcohol and the food preservatives sodium and potassium benzoate. Its sales last year were about $150 million, and it turned a slight operating profit, according to DSM. DSM put the business up for sale last September to focus on life sciences and performance materials. Upon completion of the deal, expected in the second quarter, Arsenal will rename the business Genovique Specialties. New York City-based Arsenal made a splash in the chemical industry by acquiring Rutherford Chemicals and Reilly Industries, both experts in pyridine chemistry, and ...

Methodology for the Synthesis of Pyridines and Pyridones: Development and Applications

We review some reactions devised in our laboratory for the rapid assembly of pyridines and pyridones. Applications of the new methods in the total synthesis of lavendamycin, pyridoacridine and phenanthroizidine alkaloids (pyridine chemistry), and of camptothecin, nothapodytine B and streptonigrone (pyridone-forming reactions) are described.

Supramolecular chemistry of pyridine- and pyrazine-carboxylic acids with Cu(I)

Supramolecular chemistry of pyridine- and pyrazine-carboxylic acids with Cu(I)

Recent Trends in the Chemistry of Pyridine N‐Oxides

Recent Trends in the Chemistry of Pyridine N‐Oxides

ChemInform Abstract: The Chemistry of Pyridine and Its Derivatives

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Pyridine derivatives in the drug arsenal (150 years of pyridine chemistry)

Pyridine derivatives in the drug arsenal (150 years of pyridine chemistry)

Electron-induced chemistry of pyridine on Si(111)7 × 7: a LEED and TDS study

The adsorption of pyridine on Si(111)7 × 7 at room temperature (RT) is investigated by thermal desorption spectrometry (TDS). The molecular (mass 79) desorption profile, with desorption maxima at ∼ 380 and ∼ 470 K, is found to resemble that of five-membered heterocyclic aromatic compounds including thiophene and furan. The corresponding molecular TDS profile for pyridine exposed to a sputtered Si surface consists of a single broad peak at ∼ 420 K with similar intensity as that found for the 7 × 7 surface, thus suggesting that a specific type of active sites is not essential for the pyridine adsorption. On the other hand, the large reduction in mass 79 desorption observed for pyridine exposure to an oxidized Si surface shows that Si dangling bonds are required for the initial adsorption of pyridine. In addition, a 50 L RT exposure of pyridine on Si(111)7 × 7 results in a “modified” 7 × 7 LEED pattern in which the fractional-order spots become less intense except for the off-axis (± 37, ± 37), fractional-order spots that remain relatively intense. Furthermore, the rapid conversion of the modified 7 × 7 pattern to a 1 × 1 pattern during the LEED experiment suggests that the adsorbed pyridine molecules undergo an electron-induced dissociation reaction on the Si surface. The corresponding mass 79 TDS profile is found to become broaden and less intense with increasing electron irradiation current and incident electron energy. The electron irradiation also appears to significantly increase the mass 4 (D2) desorption for RT exposure of d5-pyridine to Si(111)7 × 7, which further indicates that electron-induced dissociation of pyridine results in the deposition of C, N, and D atoms on the Si surface. It is, however, unclear if the electron-induced dissociation is a direct process or a stepwise process involving smaller intermediate fragments that further decompose during thermal annealing. Comparison of the respective TDS profiles of pyridine and benzene shows that the heteroatom appears to have the effect of reducing the adsorption of pyridine on the Si surface (in comparison to that of benzene) while inducing a greater surface reactivity. The present work further illustrates that the similarities observed in the TDS profiles for a series of homologous five-membered and six-membered aromatic compounds may not necessarily entail similar adsorption configurations and that the complex surface chemistry involved can indeed be quite different for these molecules on the Si(111) surfaces.