100-69-6Relevant articles and documents
One-Flask Pyridylethylation of Amines by 2-(2-Pyridyl)-ethanol
Ivanov, Ivo C.,Karagiosov, Stoyan K.,Sulay, Piroshka B.
, p. 181 - 182 (1989)
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OXIDATIVE DEHYDROGENATION OF ALKYLHETEROAROMATIC COMPOUNDS 1, CATALYSTS CONTAINING VANADIUM AND MOLYBDENUM FOR THE OXIDATIVE DEHYDROGENATION OF ALKYLPYRIDINES
Belomestnykh, I. P.,Rozhdestvenskaya, N. N.,Isagulyants, G. V.
, p. 701 - 708 (1994)
The dehydrogenation of a series of alkylpyridines has been studied on vanadium and molybdenum oxidecontaining catalysts in the presence of oxygen of the air and sulfur dioxide gas.A dependence was shown of the catalytic and physicochemical properties of the catalysts indicated on their composition and method of preparation.The optimum catalyst composition and the conditions of carrying out the reaction to provide high activity and selectivity when making vinylpyridines were determined.The relative reactivity of the alkylpyridines investigated on dehydrogenation and further oxidation was determined.
Concise synthesis of vinylheterocycles through β-elimination under solventless phase transfer catalysis conditions
Albanese, Domenico,Ghidoli, Cristina,Zenoni, Maurizio
, p. 736 - 739 (2008)
Various vinylheterocycles compounds have been prepared in excellent yields through β-elimination of the corresponding sulfonate esters with 50% aq NaOH under phase transfer catalysis conditions without organic solvent. The new approach provides an economic and environmentally friendly solution to removal of hazardous bases as well as toxic and expensive dipolar aprotic solvents.
Heterogeneous Gold-Catalyzed Selective Semireduction of Alkynes using Formic Acid as Hydrogen Source
Li, Shu-Shuang,Tao, Lei,Wang, Fu-Ze-Rong,Liu, Yong-Mei,Cao, Yong
, p. 1410 - 1416 (2016)
A convenient and robust protocol for the selective transfer semireduction of alkynes was developed, using bio-renewable formic acid as the hydrogen source and easily handled supported gold nanoparticles as the catalyst. The catalytic system showed several attractive features such as high activity and selectivity, recyclability, scalability and adaptability to continuous operation under mild reaction conditions, thus providing a practical alternative to current methods for alkyne semireduction.
Structure and reactivity of trans-bis[2-(2-chloroethyl)pyridine]palladium chloride (1). A study on the elimination reaction of 1 and 2-(2-chloroethyl) pyridine induced by quinuclidine in acetonitrile
Alunni, Sergio,Bellachioma, Gianfranco,Clot, Eric,Giacco, Tiziana Del,Ottavi, Laura,Zuccaccia, Daniele
, p. 10688 - 10692 (2005)
The trans-bis[2-(2-chloroethyl)pyridine]palladium chloride (1) has been prepared and structurally characterized by X-ray spectroscopy and computational study. The X-ray structure of 1 is consistent with the trans isomer (with respect to Pd). The NMR spectrum and the computational study are in agreement with an equilibrium in CD3CN solution between two isomers of the trans structure. The reaction of the palladium complex with quinuclidine in CH3CN, at 25 °C, leads to competing elimination and displacement reactions with formation of vinylpyridine and chloroethylpyridine in a ratio of 1.5:1. However, the rate constant for formation of uncoordinated (vinyl)pyridine monitored by HPLC (k;QHPLC = 2.3 × 10-3 M-1 s-1) is nearly 3 times slower than a rate constant monitored spectrophotometrically (kQ = 6.5 × 10-3 M-1 s-1). This suggests that the initial product of elimination is a palladium complex of vinylpyridine and that displacement from this complex is partially rate determining in the formation of the uncoordinated product. A study by UV spectroscopy at λ = 295 nm of trans-bis[2-(2-chloroethyl)pyridine-d2]palladium chloride with quinuclidine (Q) has shown the presence of a significant primary kinetic isotope effect, k Q(H)/kQ(D) = 1.8, for the elimination reaction within the Pd complex, 1. The second-order rate constant for the β-elimination reaction from 2-(2-chloroethyl)pyridine induced by quinuclidine in CH 3CN at 25 °C is kQFREE = 6.2 × 10-6 M-1 s-1. It can be observed as a significant activation (about 3 orders of magnitude) of the β-elimination reaction within the complex 1 with respect to the free 2-(2-chloroethyl) pyridine. The possible mechanism in agreement with these results is discussed.
Mechanistic studies of the ring opening reactions of [1,2,3]triazolo[1,5-a]pyridines
Abarca, Belen,Ballesteros, Rafael,Rodrigo, Gemma,Jones, Gurnos,Veciana, Jaume,Vidal-Gancedo, Jose
, p. 9785 - 9790 (1998)
A mechanism with radical intervention is proposed for the opening of the triazole ring in [1,2,3] triazolo[1,5-a]pyridines which results in the production of 2- or 2,6-disubstituted pyridines.
Ru-Catalyzed Completely Deoxygenative Coupling of 2-Arylethanols through Base-Induced Net Decarbonylation
Manojveer, Seetharaman,Forrest, Sebastian J. K.,Johnson, Magnus T.
, p. 803 - 807 (2018)
Substituted arylethanols can be coupled by using a readily available Ru catalyst in a fully deoxygenative manner to produce hydrocarbon chains in one step. Control experiments indicate that the first deoxygenation occurs through an aldol condensation, whereas the second occurs through a base-induced net decarbonylation. This double deoxygenation enables further development in the use of alcohols as versatile and green alkylating reagents, as well as in other fields, such as deoxygenation and upgrading of overfunctionalized biomass to produce hydrocarbons.
Cooperative C(sp3)-H and C(sp2)-H Activation of 2-Ethylpyridines by Copper and Rhodium: A Route toward Quinolizinium Salts
Luo, Ching-Zong,Gandeepan, Parthasarathy,Wu, Yun-Ching,Tsai, Chia-Hung,Cheng, Chien-Hong
, p. 4837 - 4841 (2015)
A method for the synthesis of substituted quinolizinium salts from 2-ethylpyridines and alkynes is demonstrated. The transformation is conveniently achieved using 1 mol % of a Rh(III) catalyst along with an excess amount of copper(II) salt. The reaction gives high product yields with broad substrate scope and functional group tolerance. Detailed mechanistic studies suggest that 2-vinylpyridine is formed in situ from 2-ethylpyridine by a copper-promoted C(sp3)-H hydroxylation, followed by dehydration. Later, a Rh(III)-catalyzed pyridine-directed vinylic C(sp2)-H activation and annulation with alkynes provided the final product. (Chemical Equation Presented).
Construction of α-Amino Azines via Thianthrenation-Enabled Photocatalyzed Hydroarylation of Azine-Substituted Enamides with Arenes
Zhang, Yu-Lan,Wang, Gang-Hu,Wu, Yichen,Zhu, Chun-Yin,Wang, Peng
supporting information, p. 8522 - 8526 (2021/11/13)
α-Amino azines are widely found in pharmaceuticals and ligands. Herein, we report a practical method for accessing this class of compounds via photocatalyzed hydroarylation of azine-substituted enamides with the in situ-generated aryl thianthrenium salts as the radical precursor. This reaction features a broad substrate scope, good functional group tolerance, and mild conditions and is suitable for the late-stage installation of α-amino azines in complex structures.
Piperazine-promoted gold-catalyzed hydrogenation: The influence of capping ligands
Barbosa, Eduardo C. M.,Camargo, Pedro H. C.,Fiorio, Jhonatan L.,Hashmi, A. Stephen K.,Kikuchi, Danielle K.,Rossi, Liane M.,Rudolph, Matthias
, p. 1996 - 2003 (2020/04/22)
Gold nanoparticles (NPs) combined with Lewis bases, such as piperazine, were found to perform selective hydrogenation reactions via the heterolytic cleavage of H2. Since gold nanoparticles can be prepared by many different methodologies and using different capping ligands, in this study, we investigated the influence of capping ligands adsorbed on gold surfaces on the formation of the gold-ligand interface. Citrate (Citr), poly(vinyl alcohol) (PVA), polyvinylpyrrolidone (PVP), and oleylamine (Oley)-stabilized Au NPs were not activated by piperazine for the hydrogenation of alkynes, but the catalytic activity was greatly enhanced after removing the capping ligands from the gold surface by calcination at 400 °C and the subsequent adsorption of piperazine. Therefore, the capping ligand can limit the catalytic activity if not carefully removed, demonstrating the need of a cleaner surface for a ligand-metal cooperative effect in the activation of H2 for selective semihydrogenation of various alkynes under mild reaction conditions.