2617-98-3Relevant articles and documents
Highly efficient one-pot multi-directional selective hydrogenation and N-alkylation catalyzed by Ru/LDH under mild conditions
Zhang, Sishi,Xu, Jie,Cheng, Hongmei,Zang, Cuicui,Sun, Bin,Jiang, Heyan,Bian, Fengxia
supporting information, (2020/03/30)
Atomic economy, non-toxicity, harmlessness and multidirectional selectivity advocated by green chemistry have increasingly become a hot and difficult research topic. Herein, we present a highly efficient, one-pot tandem and easy-to-operate method through which we could directly produce a broad range of multi-directional selective hydrogenated amines or N-alkyl aliphatic amines using aromatic nitro compounds as raw materials. Ru/LDH with characteristics of layered mesoporous structure, well dispersed small Ru nanoparticles and LDH stabilization to the Ru NPs was employed as the catalyst. It is remarkable that multi-directional superb chemoselectivity to aromatic amines, alicyclic amines as well as N-alkyl aliphatic amines could be achieved with excellent catalytic activity and recyclability by tuning reaction conditions over 5wt%Ru/LDH-2. Additionally, this catalytic system also exhibited attractive activity and multi-directional chemoselectivity in the hydrogenation of quinoline and its derivatives with solvents of different polarity. Chemoselectivity to 5,6,7,8-tetrahydroquinoline derivatives could reach as high as 95.6 %.
Highly Selective Hydrogenation with Ionic Liquid Stabilized Nickel Nanoparticles
Jiang, He-yan,Zhang, Si-shi,Sun, Bin
, p. 1336 - 1344 (2018/03/26)
Abstract: Nickel nanoparticles (Ni NPs) were conveniently synthesized from the reduction of nickel(II) salt with NaBH4 or hydrazine in the presence of the ionic liquid 1-butyl-2,3-dimethylimidazolium (S)-2-pyrrolidinecarboxylic acid salt. UV/Vis spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy were employed to characterize the interaction between the metal and the ionic liquid. The face-centered cubic structure of the Ni NPs(0) was confirmed by X-ray diffraction characterization. Transmission electron microscopy images revealed well-dispersed Ni particles of approximately 5.1?nm in average diameter. The ionic liquid immobilized Ni NPs were employed as highly efficient catalysts in chemoselective hydrogenation of quinoline and relevant compounds, as well as aromatic nitro compounds under mild reaction conditions. The Ni NPs can be efficiently recovered and reused. Graphical Abstract: [Figure not available: see fulltext.]
Tuning the chemoselective hydrogenation of aromatic ketones, aromatic aldehydes and quinolines catalyzed by phosphine functionalized ionic liquid stabilized ruthenium nanoparticles
Jiang, He-Yan,Zheng, Xu-Xu
, p. 3728 - 3734 (2015/07/07)
Ruthenium nanoparticles (Ru NPs) stabilized by phosphine-functionalized ionic liquids (PFILs) were synthesized in an imidazolium-based ionic liquid using H2 as a reductant. Characterization showed well-dispersed particles of about 2.2 nm (TEM) and confirmed the PFIL stabilization of the Ru NPs (NMR). The Ru NPs stabilized by PFILs exhibited excellent activity and switchable chemoselectivity in the heterogeneous selective hydrogenation of aromatic ketones, aromatic aldehydes and quinolines under mild conditions.
Hydrogenation Pathway of Quinolines over Raney Nickel and Ru/C
Okazaki, Hiroshi,Onishi, Kiyotaka,Soeda, Mahito,Ikefuji, Yoshio,Tamura, Ryuji,Mochida, Isao
, p. 3167 - 3174 (2007/10/02)
Quinoline, 2-methylquinoline, and 8-methylquinoline were hydrogenated over Raney Nickel (R-Ni) under 10 atm hydrogen pressure at about 200 deg C and over ruthenium on carbon (Ru/C) under 100 atm hydrogen pressure at 150 deg C.All the substrates were commonly hydrogenated into the initial products, 1,2,3,4-tetrahydroquinolines.The initial products were competitively converted over R-Ni to the final products, decahydroquinolines, directly or via 5,6,7,8-tetrahydroquinolines which were mainly formed from the initial products by isomerization.Ru/C promoted exclusively the direct hydrogenation of 1,2,3,4-tetrahydro derivatives to the final products.The hydrogenation and isomerization of 1,2,3,4-tetrahydroquinoline was completely inhibited in the competitive hydrogenation of quinoline and isoquinoline over R-Ni.Such features of these substrates are explained by the strong basicity of 1,2,3,4-tetrahydroisoquinoline.Roles of 1,2,3,4-tetrahydroisoquinoline are much moderate on Ru/C, where the ?-coordination may be important.The effects of methyl substituent and different reactivities of quinoline and isoquinoline are discussed in terms of the steric hindrance on adsorption, heats of hydrogenation, basicities, and electronic properties of the related compound, which are calculated according to the MNDO-PM3 method.
Regiospecific Hydrogenation of Quinolines and Indoles in the Heterocyclic Ring
Shaw, J.E.,Stapp, P.R.
, p. 1477 - 1483 (2007/10/02)
Quinolines, indoles, acridine and carbazole were hydrogenated using a large variety of heterogeneous catalysts in hydrocarbon solvents in an effort to achieve selective hydrogenation of the heterocyclic ring.When quinolines were hydrogenated using supported platinum, palladium, rhodium, ruthenium, or nickel metal catalysts in the presence of hydrogen sulfide, carbon disulfide, or carbon monoxide, there was exclusive hydrogenation of the heterocyclic ring to give only 1,2,3,4-tetrahydroquinolines.Use of iridium, rhenium, molybdenum(VI) oxide, tungsten(VI) oxide, chromium(III) oxide, iron(III) oxide, cobalt(II) oxide-molybdenum(VI) oxide, or copper chromite catalysts also caused exclusive hydrogenation of the heterocyclic ring even without addition of sulfur compounds or carbon monoxide.Hydrogenation of indoles using platinum, rhenium, or, in some cases, nickel catalysts (with or without sulfur compounds) occurred exclusively in the heterocyclic ring to give indolines, but conversions were affected by indole-indoline equilibria.
Selectivity of Hydrogenations. Part 4. 6- and 8-Substituted Quinaldines. Yield of Tetrahydroderivatives and Basicities of Quinolines
Hoenel, Michael,Vierhapper, Friedrich W.
, p. 1219 - 1228 (2007/10/02)
Hydrogenation of 6- or 8-R-substituted quinaldines over platinum in trifluoracetic acid gave higher yields (ca.90percent) of 5,6,7,8-tetrahydroderivatives than hydrogenation of the corresponding quinolines.The pKa-values of 20 quinolines and quinaldines were determined by measuring the half-neutralisation potentials in acetic anhydride.More basic quinolines gave higher yields of 5,6,7,8-tetrahydroproduct; exceptions are 6- and 8-methylquinoline and 8-tert. butylquinoline.Explanations for these observations are suggested. - Keywords:Catalytic hydrogenation; PKa-Values; Quinaldines; Quinolines; 5,6,7,8-Tetrahydroquinolines, yields of.