100-69-6Relevant articles and documents
Immobilized Pd complexes over HMMS as catalysts for Heck cross-coupling and selective hydrogenation reactions
Wang, Peng,Liu, Hengzhi,Liu, Mengmeng,Li, Rong,Ma, Jiantai
, p. 1138 - 1143 (2014)
High-performance Pd(0) on the surface of hollow magnetic mesoporous spheres (HMMS), with Fe3O4 nanoparticles embedded in the mesoporous shell was prepared. The catalyst was characterized by TEM, XRD, VSM and ICP. It showed high activity for selective hydrogenation of alkynes to alkenes and the Heck coupling reaction. The catalyst could be recovered in a facile manner from the reaction mixture and recycled six times without loss in activity.
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.
Palladium-catalyzed 2-pyridylmethyl transfer from 2-(2-pyridyl)-ethanol derivatives to organic halides by chelation-assisted cleavage of unstrained Csp3-Csp3 bonds
Niwa, Takashi,Yorimitsu, Hideki,Oshima, Koichiro
, p. 2643 - 2645 (2007)
(Chemical Equation Presented) Making a break for it: Treatment of 2-(2-pyridyl)ethanol derivatives with aryl chlorides in the presence of a palladium catalyst results in the transfer of the pyridylmethyl moiety of the alcohol to yield the corresponding (2-pyridyl-methyl)arene. The reaction proceeds by chelation-assisted cleavage of an Csp3-C5p3 bond (see scheme) followed by formation of a carbon-carbon bond.
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.
Continuous Flow Process for the Synthesis of Betahistine via Aza-Michael-Type Reaction in Water
Sun, Maolin,Yang, Jingxin,Fu, Youtian,Liang, Chaoming,Li, Hong,Yan, Guoming,Yin, Chao,Yu, Wei,Ma, Yueyue,Cheng, Ruihua,Ye, Jinxing
, p. 1160 - 1166 (2021)
A continuous flow process for the preparation of betahistine with a 90% isolated yield has been reported. 2-Vinylpyridine and saturated methylamine hydrochloride aqueous solution were used as starting materials to achieve excellent results in the silicon carbide flow reactor, which can tolerate the corrosion of chloride ions at high temperature (170 °C) and pressure (25 bar). In the continuous flow process, the product can be obtained in 2.4 min with excellent conversion (>99%) and product selectivity (94%). The throughput can reach 1.06 kg h-1, and the purity of the final product was greater than 99.9% by distillation, which were in accordance with the needs of production. This new process using environmentally friendly water as the solvent is energy-efficient, time- and cost-economic, and offers a 50% reduction in process mass intensity compared to the batch process.
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.
Steuerung der katalytischen Pyridinsynthese aus Alkinen und Nitrilen durch (η6-Borinato)-Liganden am Cobalt
Boennemann, Helmut,Brijoux, Werner,Brinkmann, Rainer,Meurers, Willi
, p. 1616 - 1624 (1984)
η6-Borinato groups as ligands at cobalt have unique effects on the chemo- and regioselectivity of the catalytic co-cyclization of alkynes and nitriles.The turnover number of the conversion of acrylonitrile and acetylene to give 2-vinylpyridine is considerably enhanced.Cyano compounds with polar substituents such as amino or thio groups can also be reacted.The homogenous reaction of HCN with acetylene giving pyridine has been achieved for the first time.
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.
