Category: pyridine-derivatives

Hoque, Emdadul Md; Bisht, Ranjana; Unnikrishnan, Anju; Dey, Sayan; Mahamudul Hassan, Mirja Md; Guria, Saikat; Rai, Rama Nand; Sunoj, Raghavan B.; Chattopadhyay, Buddhadeb published the artcile< Iridium-Catalyzed Ligand-Controlled Remote para-Selective C-H Activation and Borylation of Twisted Aromatic Amides>, Synthetic Route of 329214-79-1, the main research area is regioselective remote para borylation CH activation twisted aromatic amide; aryl boronate preparation regioselective remote para borylation aromatic amide; potential energy surface para CH borylation twisted aromatic amide; Borylation; C−H Activation; Density Functional Calculations; Iridium Catalyst; Para Selectivity.

A method of para-selective borylation of fully twisted aromatic amides ArCONBoc2 is described, yielding boronamides 4-pinBC6HnX4-nCONBoc2 (X = alkyl, alkoxy, aryl, halo, CN). The borylation proceeded via an unprecedented substrate-ligand distortion between the twisted aromatic amides and a newly designed ligand framework, 4,5-diaza-9H-fluorene (defa) that is different from the traditionally used ligand (dtbpy) for the C-H borylation reactions. The designed ligand defa has led to the development of a new type of catalytic system that shows excellent para selectivity for a range of aromatic amides. Moreover, the designed ligand has shown excellent reactivity and selectivity for a range of heterocyclic aromatic amides. The identification of key transition states and intermediates using the DFT computations associated with the three regio-isomeric pathways revealed that the most efficient catalytic pathway with the defa ligand leads to the para borylation while in the case of bpy the borylation at the para and meta sites compete.

Angewandte Chemie, International Edition published new progress about Aromatic amides Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 329214-79-1 belongs to class pyridine-derivatives, and the molecular formula is C11H16BNO2, Synthetic Route of 329214-79-1.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Zhang, Qun-Liang; Yu, Qin-qin; Ma, Li; Lu, Xuelian; Fan, Qing-Tian; Duan, Tian-Shun; Zhou, Yirong; Zhang, Fang-Lin published the artcile< A Metal-Free Visible-Light Photoredox Construction and Direct C-H Functionalization of Pyridines: Green Synthesis of Polysubstituted Picolinaldehydes>, COA of Formula: C6H4F3N, the main research area is picolinaldehyde preparation green chem; pyridine metal free visible light electrocyclization tandem Minisci reaction.

The development of a novel environmental benign and sustainable synthetic method for highly efficient construction and direct C-H functionalization of N-heterocycles remains a pivotal central research topic for organic and medicinal chem. Herein, a novel visible-light-enabled biomimetic aza-6π electrocyclization for efficient assembly of diverse pyridines and further tandem Minisci-type reaction were developed. A broad spectrum of polysubstituted picolinaldehydes were readily constructed with high efficacy and good functional group tolerance under metal- and oxidant-free conditions.

Journal of Organic Chemistry published new progress about Cyclization, electrophilic. 3796-23-4 belongs to class pyridine-derivatives, and the molecular formula is C6H4F3N, COA of Formula: C6H4F3N.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Umasankar, Gorakala; Busireddy, Manohar Reddy; Kotamarthi, Bhanuprakash; Karunakar, Galla V.; Rao, Vaidya Jayathirtha published the artcile< Pyrene appended terpyridine derivatives as electrochemiluminescence material for OLEDs: Characterization of photo-physical, thermal and electrochemical properties>, Formula: C7H7NO, the main research area is structure property relationship pyrenyl terpyridine; terpyridine pyrenyl fluorophore preparation photophys electrochem thermal electrochemiluminescence.

Three new terpyridine-appended pyrene derivatives I, II and III have been synthesized by condensation or Suzuki-Miyaura reaction. The photophys., electrochem. and thermal properties of these compounds have been investigated in detail. DFT studies have been carried out to understand the structure-property relationships at the mol. level. The synthesized fluorophores displayed high quantum yield (70-96%) of fluorescence due to triplet to singlet intramol. energy transfer, delayed fluorescence and pos. solvatochromism indicating the presence of an intramol. charge transfer excited state. In addition, they have high thermal decomposition temperatures (Td: 390-450°C), melting temperatures (Tm: 180-220°C); and further, they have suitable oxidation and reduction potentials that make them favorable mols. for OLED fabrications.

Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry published new progress about Claisen condensation. 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Formula: C7H7NO.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Wang, Zhaobin; Yang, Ze-Peng; Fu, Gregory C. published the artcile< Quaternary stereocentres via catalytic enantioconvergent nucleophilic substitution reactions of tertiary alkyl halides>, Reference of 1416819-91-4, the main research area is nickel catalytic enantioconvergent nucleophilic substitution tertiary alkyl electrophiles alkenylzirconium.

The development of efficient methods, particularly catalytic and enantioselective processes, for the construction of all-carbon quaternary stereocentres is an important (and difficult) challenge in organic synthesis due to the occurrence of this motif in a range of bioactive mols. One conceptually straightforward and potentially versatile approach is the catalytic enantioconvergent substitution reaction of a readily available racemic tertiary alkyl electrophile by an organometallic nucleophile; however, examples of such processes are rare. Here we demonstrate that a nickel-based chiral catalyst achieves enantioconvergent couplings of a variety of tertiary electrophiles (cyclic and acyclic α-halocarbonyl compounds) with alkenylmetal nucleophiles to form quaternary stereocentres with good yield and enantioselectivity under mild conditions in the presence of a range of functional groups. These couplings, which probably proceed via a radical pathway, provide access to an array of useful families of organic compounds, including intermediates in the total synthesis of two natural products, (-)-eburnamonine and madindoline A.

Nature Chemistry published new progress about Alkenylation catalysts, stereoselective. 1416819-91-4 belongs to class pyridine-derivatives, and the molecular formula is C13H15F3N2O, Reference of 1416819-91-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Anantoju, Kishore Kumar; Tharikoppula, Giri; Eppakayala, Laxminarayana; Maringanti, Thirumala Chary published the artcile< A facile synthesis of methyl-2-(N-ethyl-N-phenylamino)naphthyridine-3-carboxylates>, Product Details of C6H6N2O, the main research area is pyridinecarboxaldehyde amino malonamide Friedlander condensation heterocyclization; naphthyridine carboxylic acid preparation esterification; phenylamino naphthyridine carboxylate preparation.

An efficient protocol for the synthesis of Me 2-(N-ethyl-N-phenylamino)naphthyridine-3-carboxylates I (X = N, Y = Z = CH; Y = N, X = Z = CH; Z = N, X = Y = CH) was developed. The methodol. is cost effective and provided an efficient alternative to existing methods for the synthesis of 2-substituted naphthyridine-3-carboxylic acids.

International Journal of Chemical and Analytical Science published new progress about Aminals Role: RCT (Reactant), RACT (Reactant or Reagent). 55279-29-3 belongs to class pyridine-derivatives, and the molecular formula is C6H6N2O, Product Details of C6H6N2O.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Zhang, Jiang; Chen, Xu-Feng; Huang, Wei-Tao; Chen, Huan-Huan; Lai, Ning-Wei; Yang, Lin-Tong; Huang, Zeng-Rong; Guo, Jiuxin; Ye, Xin; Chen, Li-Song published the artcile< Mechanisms for increased pH-mediated amelioration of copper toxicity in Citrus sinensis leaves using physiology, transcriptomics and metabolomics>, Quality Control of 93-60-7, the main research area is copper Citrus leaf toxicity transcriptomic metabolomic.

Limited data are available on the mol. and physiol. mechanisms for increased pH-mediated amelioration of copper (Cu) toxicity in plants. Citrus sinensis seedlings were fertilized with a nutrient solution at the Cu concentration of 300 (Cu toxicity) or 0.5μM (control) and a pH of 3.0, 4.0, or 4.8 for 17 wk. Subsequently, we examined the interactive effects of low pH and Cu toxicity on transcriptomics, metabolomics, and some physiol. parameters in leaves. Our results demonstrated that increased pH reduced Cu toxicity-induced leaf Cu accumulation and oxidative damage by reducing reactive oxygen species (ROS) production and maintaining the homeostasis of sulfur (S)-containing compounds (reduced glutathione), ascorbate, and cell redox potential, thus mitigating Cu toxic effects on leaf chlorophyll biosynthesis, photosynthesis, and metabolisms of carbohydrates, lipids, amino acids, and secondary metabolites. The increased pH mitigated Cu toxicity-induced impairment of cell wall metabolism by reducing cell wall Cu concentration, thus improving leaf growth. Under low pH (pH 3.0), C. sinensis leaves also displayed some adaptive responses to Cu toxicity to meet the increased demand for the dissipation of excess light energy and the detoxification of Cu and ROS, including: (a) increased distribution of Cu in cell wall; (b) elevated photorespiration and thermal dissipation. And increased accumulation of nonstructural carbohydrates [fructose, glucose, starch, total nonstructural carbohydrates (the summation of fructose + glucose + sucrose + starch), maltotetraose and 1,1-kestotetraose] and upregulation of metabolism (glycolysis/gluconeogenesis, pyruvate metabolism and pentose phosphate pathway) related to energy production; (d) downregulation of phospholipid [LysoPC 18:3(2 n isomer)] and phosphate-containing compounds (2′-deoxycytidine-5′-monophosphate and AMP) and upregulation of -tryptophan metabolism and related amino acids (-tryptophan and 5-hydroxy–tryptophan); and (e) increased accumulation of some secondary metabolites [total phenolics, lignin, alkaloids (3-indoleacrylic acid, N-acetyl-5-hydroxytryptamine and Me nicotinate), plumerane (indole and 3-indolepropionic acid) and coumarins (isoscopoletin, scopoletin, skimming and scopolin)]. However, these adaptive responses could not protect low pH-treated leaves from Cu toxicity, as indicated by elevated malondialdehyde accumulation and electrolyte leakage and decreased photosynthesis and chlorophyll level in leaves as well as reduced leaf growth due to impaired cell metabolism Cu toxicity intensified the adverse effects of low pH on C. sinensis leaves.

Environmental and Experimental Botany published new progress about Amino acids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 93-60-7 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO2, Quality Control of 93-60-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Omidvar, Rose; Wu, Shijian; Mohammadigoushki, Hadi published the artcile< Detecting wormlike micellar microstructure using extensional rheology>, Name: 1-Hexadecylpyridin-1-ium chloride, the main research area is wormlike micellar microstructure rheol.

We report experiments on two series of wormlike micellar solutions that comprise octyl trimethylammonium bromide/sodium oleate (OTAB/NaOA) and cetylpyridinium chloride/sodium salicylate (CPCl/NaSal) using a capillary breakup extensional rheometer (CaBER) and a dripping onto substrate (DoS) technique. These wormlike micellar systems show a peak in zero shear viscosity or in the shear relaxation time beyond a critical surfactant or salt concentration Prior cryogenic transmission electron microscopy imaging has indicated that the system based on OTAB/NaOA experiences a transition from linear to shorter linear micelles (L-L) beyond the viscosity peak. However, the linear wormlike micelles based on CPCl/NaSal form branched networks beyond the viscosity peak (L-B). In this work, we investigate whether the extensional rheol. is sensitive to these two different microstructural transitions. In particular, we attempt to develop a criterion based on the extensional flow parameters in order to distinguish these two systems from each other. In addition, we probe the possibility of flow-induced micellar breakage imposed by capillary breakup extensional experiments Our results indicate that at a given zero shear viscosity, the branched wormlike micelles based on CPCl/NaSal exhibit a longer filament lifetime tfil than the linear wormlike micelles. However, beyond the critical concentration, the linear wormlike micelles based on OTAB/NaOA exhibit significantly shorter filament lifetimes than their linear counterparts at concentrations below the viscosity peak. More importantly, we show that the filament lifetime scales differently with zero shear viscosity η0 in these two systems. For L-B transition, tfilαη01.1 below the viscosity peak and tfilαη00.76above the viscosity peak. However, for L-L transition, this scaling remains the same for concentrations below and above the viscosity peak and reads as tfilαη00.5. These findings provide a novel criterion to distinguish these two types of microstructural transitions in wormlike micelles. On the other hand, we demonstrate that the Trouton ratio, filament lifetime, and the extensional relaxation time measured by CaBER technique are all lower than the ones obtained by DoS method. The latter result provides the first evidence for strong nonlinear effects (e.g., flow-induced micellar breakage) in capillary breakup extensional flows of wormlike micelles. (c) 2019 American Institute of Physics.

Journal of Rheology (Melville, NY, United States) published new progress about Dimensionless number, Weissenberg. 123-03-5 belongs to class pyridine-derivatives, and the molecular formula is C21H38ClN, Name: 1-Hexadecylpyridin-1-ium chloride.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Maegawa, Tomohiro; Oishi, Ryohei; Maekawa, Ayumi; Segi, Kazutoshi; Hamamoto, Hiromi; Nakamura, Akira; Miki, Yasuyoshi published the artcile< The Reaction of Ketoximes with Hypervalent Iodine Reagents: Beckmann Rearrangement and Hydrolysis to Ketones>, Quality Control of 350-03-8, the main research area is ketoxime hypervalent iodine Beckmann rearrangement; amide preparation; oxime hypervalent iodine reagent hydrolysis; ketone preparation.

The reaction of ketoximes with hypervalent iodine reagents was investigated. A combination of PhI(OAc) 2 and BF3·Et2O promoted the Beckmann rearrangement of ketoximes, thus yielding the corresponding amides. From a detailed investigation of the reaction, it was determined that the Beckmann rearrangement is preceded by acetylation of the hydroxy group of the ketoxime in situ, accelerating the Beckmann rearrangement. The acetylated ketoxime undergoes the Beckmann rearrangement with BF3·Et2O was confirmed. The reaction of ketoximes with Koser’s reagent [PhI(OH)OTs] in the presence of THF results in hydrolysis, affording the corresponding ketones in high yields at room temperature

Synthesis published new progress about Amides Role: SPN (Synthetic Preparation), PREP (Preparation). 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Quality Control of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem