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Upstream product

• 766-98-3 1-ethynyl-4-fluorobenzene 
• 100-46-9 benzylamine 
• 1765-93-1 4-fluoroboronic acid 
• 100-52-7 benzaldehyde 
• 75-05-8 acetonitrile 
• 103-82-2 phenylacetic acid 
• 896885-34-0 1-(4-fluorophenyl)ethan-1-one-O-acetyl oxime 
• 403-42-9 1-(4-fluorophenyl)ethanone 
• 108-88-3 toluene 
• 939-23-1 p-phenylpyridine 
• 460-00-4 1-Bromo-4-fluorobenzene 
• 399-10-0 4'-fluorochalcone 
• 100-51-6 benzyl alcohol 
• 2475-92-5 4-methoxyacetophenone oxime 

Relevant academic research and scientific papers

An efficient one pot three-component synthesis of 2,4,6-triarylpyridines using triflimide as a metal-free catalyst under solvent-free conditions

A simple and efficient protocol developed for one pot three-component synthesis of 2,4,6-triarylpyridines from aromatic aldehydes, substituted acetophenones and ammonium acetate using the versatile super Br?nsted acid triflimide (HNTf2) as an effective catalyst is described. The reactions proceed well in the presence of 1 mol% of HNTf2 at 80 °c under solvent-free conditions and provide the corresponding triarylpyridines in good to excellent yields. The method reported has several advantages such as a metal-free and commercially available catalyst, mild reaction conditions and lower loading of catalyst.

TMSOTf-mediated Kr?hnke pyridine synthesis using HMDS as the nitrogen source under microwave irradiation

An efficient protocol for the preparation of pyridine skeletons has been successfully developed involving the TMSOTf/HMDS (trifluoromethanesulfonic acid/hexamethyldisilane) system for the intermolecular cyclization of chalcones under MW (microwave) irradiation conditions. This method provides a facile approach to synthesize 2,4,6-triaryl or 3-benzyl-2,4,6-triarylpyridines in good to excellent yields. Interestingly, the 2,6-diazabicyclo[2.2.2]oct-2-ene core was obtained by changing the acid additive to Sn(OTf)2, and the desired product was also confirmed using X-ray single-crystal diffraction analysis.

Synthesis of Kr?hnke pyridines through iron-catalyzed oxidative condensation/double alkynylation/amination cascade strategy

An efficient protocol for the synthesis of symmetrical and unsymmetrical 2,4,6-trisubstituted pyridines via oxidative cascade annulation of arylacetylenes with benzylamines has been developed. The reaction proceeds smoothly utilizing iron(II) triflate as a catalyst and molecular oxygen as an oxidant with broad substrate scope. Mechanistic studies reveal that the reaction may be experiences an oxidative condensation followed by double alkynylation and amination process.

Copper-catalyzed efficient access to 2,4,6-triphenyl pyridinesviaoxidative decarboxylative coupling of aryl acetic acids with oxime acetates

An efficient and concise approach for the synthesis of 2,4,6-triphenyl pyridines has been developed through copper-catalysed oxidative decarboxylative coupling of C(sp3) aryl acetic acids with oxime acetates in DMF at 150 °C under an oxygen atm

Pyridine Skeleton Synthesis Using Acetonitrile as C4N1 Units and Solvent

The first [3 + 2 + 1] methodology for pyridine skeleton synthesis via cascade carbopalladation/cyclization of acetonitrile, arylboronic acids, and aldehydes was developed. This reaction proceeds via six step tandem reaction sequences involving the carbopalladation reaction of acetonitrile, a nucleophilic addition, a condensation, an intramolecular Michael addition, cyclization, and aromatization. Delightfully, both palladium acetate and supported palladium nanoparticles catalyzed this reaction with similar catalytic performance. The characterization results of the fresh and used supported palladium nanoparticle catalysts indicated that the reaction might be performed via a Pd(0)/Pd(II) catalytic cycle that began with Pd(0). Furthermore, the products showed good fluorescence characteristics. The green homogeneous/heterogenous catalytic methodologies pave a new way for constructing the pyridine skeleton.

Cationic organotin cluster [t-Bu2Sn(OH)(H2O)]2 2+2OTf?-catalyzed one-pot three-component syntheses of 5-substituted 1H-tetrazoles and 2,4,6-triarylpyridines in water

The cationic organotin cluster [t-Bu2Sn(OH)(H2O)]2 2+2OTf? is easy to prepare and stable in air. The catalytic activity of [t-Bu2Sn(OH)(H2O)]2 2+2OTf? as a neutral organotin Lewis acid catalyst is probed through the one-pot three-component syntheses of 5-substituted 1H-tetrazoles from aldehydes, hydroxylamine hydrochloride and sodium azide, and of 2,4,6-triarylpyridines from aromatic aldehydes, substituted acetophenones and ammonium acetate. The reactions proceed well in the presence of 1?mol% of [t-Bu2Sn(OH)(H2O)]2 2+2OTf? in water and provide the corresponding 5-substituted 1H-tetrazoles and 2,4,6-triarylpyridines in good to excellent yields. The method reported has several advantages such as the catalyst being neutral, low catalyst loading and use of water as a green solvent.

Merrifield resin-supported quinone as an efficient biomimetic catalyst for metal-free, base-free, chemoselective synthesis of 2,4,6-trisubstituted pyridines

Metal-free, base-free, biomimetic and chemoselective synthesis of 2,4,6-trisubstituted pyridines was developed under mild conditions for the first time. The heterogeneous biomimetic catalyst-recoverable Merrifield resin-supported quinone-was fully characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometry (XPS) and energy dispersive X-ray spectroscopy (EDX). This supported quinone catalyst exhibited excellent catalytic reactivity for chemoselective synthesis of 2,4,6-trisubstituted pyridines, providing an efficient and green method for the synthesis of pyridine derivatives under mild conditions. Mechanistic investigations were conducted to gain insights into the heterogeneous biomimetic catalyst as well as the resulting transformation. The successful capture of intermediates offered direct and clear evidence for the proposed mechanism.

B(C6F5)3-catalyzed oxidative deamination/cyclization cascade reaction of benzylamines and ketones for the synthesis of 2,4,6-triarylpyridines

The B(C6F5)3-catalyzed oxidative deamination/cyclization cascade reaction of benzylamines and ketones for the construction of 2,4,6-triarylpyridines under metal-/solvent-free conditions has been successfully achieved. The advantages of this strategy include good functional group tolerance, low catalyst loading and high yields.

Application of a novel, efficient and recyclable photo redox catalyst (Zn–Al layered double hydroxide/eosin) for the synthesis of substituted pyridine derivatives under visible light irradiation

Layered double hydroxides (LDHs) are a class of anionic clays with brucite-like layers and interlayer anions and varying in composition and morphology. LDHs show potential as supports for the immobilization of catalytically active species, to synthesize recyclable catalysts, in which catalytic sites can be preferentially orientated, highly dispersed and stabilized to afford high catalytic efficiency and recyclability in reaction media. Redox active organic dyes such as eosin Y with strong absorption in the visible region of the spectrum have been successfully used. In this work, an intercalated photo redox catalyst (Zn–Al LDH/eosin) was synthesized by co-precipitation of an aqueous solution of zinc nitrate and aluminium nitrate simultaneously with eosin Y as anionic dye. Zn–Al LDH/eosin as a recyclable catalyst was used in the reaction of various aryl ketones and benzylamines under molecular oxygen and visible light, giving good yields of substituted pyridines at room temperature. Also, the Zn–Al LDH/eosin catalyst could be reused three times without any significant changes in the reaction yields.

Acid-catalyzed tandem reaction for the synthesis of pyridine derivatives via C=C/C(sp3)-N bond cleavage of enones and primary amines

A one-pot acid-catalyzed tandem reaction has been developed without any metallic reagents or extra oxidants. This reaction involves a C=C bond cleavage of enones via a “masked” reverse Aldol reaction, and C(sp3)-N bond cleavage of primary amines to provide nitrogen sources for the assembly of pyridine derivatives in high yields with excellent functional group tolerance.