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PRODUCTION METHOD OF CYCLIC COMPOUND
PROBLEM TO BE SOLVED: To provide an industrially simple production method of a cyclic compound. SOLUTION: A production method of a cyclic compound includes a step to obtain a reduced form (B) by reducing an unsaturated bond in a ring structure of an aromatic compound (A) by means of catalytic hydrogenation of the aromatic compound (A) or its salt using palladium carbon as a catalyst under a normal pressure, in which the aromatic compound (A) has one or more ring structures selected from a group consisting of a five membered-ring, a six membered-ring, and a condensed ring of the five membered-ring or the six membered-ring with another six membered-ring, a hetero atom can be included in the ring structure, and the aromatic compound (A) can have one or two side chains bonded to the ring structure and does not have any carbon-carbon triple bond in the side chain. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0057; 0059; 0062-0063

(2021/05/05)

Organometallic Synthesis of Bimetallic Cobalt-Rhodium Nanoparticles in Supported Ionic Liquid Phases (CoxRh100?x@SILP) as Catalysts for the Selective Hydrogenation of Multifunctional Aromatic Substrates
The synthesis, characterization, and catalytic properties of bimetallic cobalt-rhodium nanoparticles of defined Co:Rh ratios immobilized in an imidazolium-based supported ionic liquid phase (CoxRh100?x@SILP) are described. Following an organometallic approach, precise control of the Co:Rh ratios is accomplished. Electron microscopy and X-ray absorption spectroscopy confirm the formation of small, well-dispersed, and homogeneously alloyed zero-valent bimetallic nanoparticles in all investigated materials. Benzylideneacetone and various bicyclic heteroaromatics are used as chemical probes to investigate the hydrogenation performances of the CoxRh100?x@SILP materials. The Co:Rh ratio of the nanoparticles is found to have a critical influence on observed activity and selectivity, with clear synergistic effects arising from the combination of the noble metal and its 3d congener. In particular, the ability of CoxRh100?x@SILP catalysts to hydrogenate 6-membered aromatic rings is found to experience a remarkable sharp switch in a narrow composition range between Co25Rh75 (full ring hydrogenation) and Co30Rh70 (no ring hydrogenation).
Rengshausen, Simon,Van Stappen, Casey,Levin, Natalia,Tricard, Simon,Luska, Kylie L.,DeBeer, Serena,Chaudret, Bruno,Bordet, Alexis,Leitner, Walter
(2020/12/22)

A confined thermal transformation strategy to synthesize single atom catalysts supported on nitrogen-doped mesoporous carbon nanospheres for selective hydrogenation
Carbon-supported single-atom catalysts (SACs) have brought considerable attention to heterogeneous catalysis, but they, however, often suffer from low activity due to the mass transfer limitation. Herein, we report a soft-templating method to synthesize core-shell mesostructured polymer nanospheres with metal nanoclusters (M-NCs, M = Pd, Pt) as the core, which can be easily converted into nitrogen-doped mesoporous carbon nanosphere (NMCS) supported SACs (M1/NMCS) after a confined thermal transformation process. Through this strategy, Pd1/NMCS and Pt1/NMCS are successfully prepared with rich porosity and high N content. The abundant N species in M1/NMCS can be employed as anchoring sites to capture and stabilize the single metal atoms. In addition, the mesoporous structure of M1/NMCS is beneficial for the mass transfer and the exposure of active sites. Benefiting from such a unique structure, the as-obtained Pd1/NMCS exhibits excellent activity, selectivity, and long-term stability in the selective hydrogenation of quinoline.
Tian, Zhengbin,Wang, Guang-Hui,Wang, Wenquan,Zheng, Yan
p. 25488 - 25494
(2021/12/07)

Nano-Ni-MOFs: High Active Catalysts on the Cascade Hydrogenation of Quinolines
Abstract: The reduction of nitrogen-containing heterocyclic compounds in aqueous medium under mild condition is quite challenging. In view of metal–organic frameworks (MOFs) possess adjustable pore size and modifiable organic linkers, MOFs could be used in heterogeneous catalysis. Herein, Three Nano-Ni-MOFs, MOF-74-Ni, MOF-69-Ni, and Ni–NH2 (constructed from similar ligands and Ni2+ ions) are introduced for hydrogenating of azacyclo-compounds. As expected, Ni–NH2 shows outstanding activity of hydrogenation of quinoline under mild conditions, due to the moderate pore size and the modified –NH2 function group, which makes the substrate anchored on the surface of the framework facilitate the following catalysis process. Theoretical calculations identified that the –NH2 group at the catalyst facilitates the H2 heterolytic dissociation for the hydrogenation reactions. Graphic Abstract: Compared to MOF-74-Ni and MOF-69-Ni, the catalyst of Ni–NH2 shows outstanding activity of hydrogenation of quinoline, due to the modified –NH2 function group which makes the substrate anchored on the surface of the framework facilitate the following catalysis process[Figure not available: see fulltext.]
Yun, Ruirui,Ma, Zi-Wei,Hu, Yang,Zhan, Feiyang,Qiu, Chuang,Zheng, Baishu,Sheng, Tian
p. 2445 - 2451
(2021/01/05)

Aromatic compound hydrogenation and hydrodeoxygenation method and application thereof
The invention belongs to the technical field of medicines, and discloses an aromatic compound hydrogenation and hydrodeoxygenation method under mild conditions and application of the method in hydrogenation and hydrodeoxygenation reactions of the aromatic compounds and related mixtures. Specifically, the method comprises the following steps: contacting the aromatic compound or a mixture containing the aromatic compound with a catalyst and hydrogen with proper pressure in a solvent under a proper temperature condition, and reacting the hydrogen, the solvent and the aromatic compound under the action of the catalyst to obtain a corresponding hydrogenation product or/and a hydrodeoxygenation product without an oxygen-containing substituent group. The invention also discloses specific implementation conditions of the method and an aromatic compound structure type applicable to the method. The hydrogenation and hydrodeoxygenation reaction method used in the invention has the advantages of mild reaction conditions, high hydrodeoxygenation efficiency, wide substrate applicability, convenient post-treatment, and good laboratory and industrial application prospects.
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Paragraph 0094-0095; 0114-0122

(2021/05/29)

Highly efficient one-pot multi-directional selective hydrogenation and N-alkylation catalyzed by Ru/LDH under mild conditions
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 %.
Zhang, Sishi,Xu, Jie,Cheng, Hongmei,Zang, Cuicui,Sun, Bin,Jiang, Heyan,Bian, Fengxia
supporting information

(2020/03/30)

Effect of Zr on catalytic performance of unsupported Ni(Zr)Mo and Ni(Zr)W sulfide catalysts for quinoline hydrodenitrogenation
To increase the dispersion of active species and full utilization of active metals are of great importance for hydrodenitrogenation (HDN) performance of unsupported hydrotreating catalysts. Herein, a series of unsupported Ni(Zr)MoS and Ni(Zr)WS catalysts were prepared from Ni(Zr) layered double hydroxide (LDH) precursors. The Zr species remarkably promote the dispersion and reducibility of NiMo and NiW composite species. Also, the total HDN rate constants are increased from 2.42 h?1 to 9.18 h?1 for Ni(Zr)MoS and from 5.68 h?1 to 23.0 h?1 for Ni(Zr)WS, and exhibit a maximum at a Zr/Ni atomic ratio of about 0.04. The HDN selectivities indicate that the Zr species increase the number of superficial active sites without affecting their structure. The present work shows that the crystallinity of LDH precursors is crucial to the structure of unsupported sulfide catalysts, and a suitable amount of Zr could be a dispersive promoter to increase the HDN activity.
Jiang, Zongxuan,Li, Can,Liu, Tiefeng,Liu, Xinyi,Zhang, Cen
(2020/08/19)

One-pot dual catalysis for the hydrogenation of heteroarenes and arenes
A simple dinuclear monohydrido bridged ruthenium complex [{(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] acts as an efficient and selective catalyst for the hydrogenation of various heteroarenes and arenes. The nature of the catalytically active species was investigated using a combination of techniques including in situ reaction monitoring, kinetic studies, quantitative poisoning experiments and electron microscopy, evidencing a dual reactivity. The results suggest that the hydrogenation of heteroarenes proceeds via molecular catalysis. In particular, monitoring the reaction progress by NMR spectroscopy indicates that [{(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] is transformed into monomeric ruthenium intermediates, which upon subsequent activation of dihydrogen and hydride transfer accomplish the hydrogenation of heteroarenes under homogeneous conditions. In contrast, carbocyclic aryl motifs are hydrogenated via a heterogeneous pathway, by in situ generated ruthenium nanoparticles. Remarkably, these hydrogenation reactions can be performed using molecular hydrogen under solvent-free conditions or with 1,4-dioxane, and thus give access to a broad range of saturated heterocycles and carbocycles while generating no waste.
Chatterjee, Basujit,Kalsi, Deepti,Kaithal, Akash,Bordet, Alexis,Leitner, Walter,Gunanathan, Chidambaram
p. 5163 - 5170
(2020/09/07)

PtRuNi/C novel nanostructures of platinum-ruthenium island-on-Ni/Ni(OH)2 nanoparticles for the selective hydrogenation of quinoline
Ni/C was successfully synthesized via hydrazine hydrate reduction at room temperature (RT). Pt/C, Ru/C and PtRu/C were prepared via an impregnation method. PtNi/C, RuNi/C and PtRuNi/C were synthesized via a chemical replacement method. The characterization results revealed that PtRuNi nanoparticles (NPs) were highly and uniformly dispersed on carbon black in PtRuNi/C. PtRuNi/C showed a novel nanostructure in which PtRu islands (PtRu nanoclusters or PtRu binary atoms) covered Ni/Ni(OH)2 NPs. PtRuNi/C trimetallic nanomaterial exhibited an optimum catalytic performance (turnover frequency (TOF) = 211.4 h?1 and selectivity for the production of 1,2,3,4-tetrahydroquinoline (py-THQ) > 99%) in the selective hydrogenation of quinoline at 60 °C under 5.0 MPa H2. The catalytic properties of PtRuNi/C were significantly improved as compared to bimetallic (PtNi/C, RuNi/C and PtRu/C) and monometallic (Ni/C, Pt/C and Ru/C) nanomaterials due to its unique nanostructure, with an observed nano-synergy effect among Pt-, Ru- and Ni-related species.
Chen, Bing Hui,Liao, Jianhua,Pei, An,Ruan, Luna,Wang, Jiexiang,Yang, Kai,Zhang, Huan,Zhu, Lihua
(2020/04/27)

Facile Synthesis of Size-Controlled Nitrogen-Doped Mesoporous Carbon Nanosphere Supported Ultrafine Ru Nanoparticles for Selective Hydrogenation of Quinolines
Nitrogen-doped mesoporous carbon nanosphere (NMCS) with tunable sizes and uniform mesoporosity was synthesized by a facile soft-templating method. During the synthesis, F127 (PEO–PPO–PEO triblock copolymer) could be used not only as a soft template to generate the mesostructure but also as a size-control agent to tailor the size of NMCS in a relatively wide range of 100 to 700 nm. In addition, the synthesis process was simple and suitable for large-scale production. Moreover, the NMCS was used as support of ultrafine Ru nanoparticles (Ru/NMCS), which exhibited good catalytic performances for selective hydrogenation of quinolones. It is expected that the simple synthetic strategy for the NMCS can generate extensive interest in many catalysis and sorption applications.
Huang, Minghua,Jiang, Haibin,Tian, Zhengbin,Wang, Guang-Hui
p. 17000 - 17004
(2020/11/30)

Recyclable Rh-PVP nanoparticles catalyzed hydrogenation of benzoic acid derivatives and quinolines under solvent-free conditions
Various transition metal nanoparticles, prepared by microwave-assisted alcohol reduction method were examined for hydrogenation of benzoic acid to cyclohexanecarboxylic acid under solvent-free conditions. Rh metal was the most effective catalyst over other metal catalyst. The catalyst showed moderate to high yield for the hydrogenation of substituted benzoic acid and substituted quinolines. Rh-PVP was recycled four times with a minor loss in catalytic activity.
Chaudhari, Chandan,Imatome, Hirotaka,Nishida, Yoshihide,Sato, Katsutoshi,Nagaoka, Katsutoshi
p. 55 - 60
(2019/05/10)

Chemoselective reduction of quinoline over Rh-C60 nanocatalysts
The design and engineering of heterogeneous nanocatalysts that are both highly active and selective for hydrogenation reactions constitute a crucial challenge. In that context, herein a series of Rh-C60 nanocatalysts have been synthesized via the decomposition of an organometallic rhodium complex in the presence of fullerene C60 under a H2 atmosphere. Rhodium atomically dispersed or rhodium nanoparticles on Rh-C60 spherical fulleride particles were produced by tuning the Rh/C60 molar ratio. Significant charge transfer between rhodium and C60 was evidenced through Raman and X-ray photoelectron spectroscopy, which indicates electron-deficient Rh species. The resulting heterostructured nanomaterials were applied successfully in the catalytic hydrogenation of quinoline, exhibiting excellent activity and producing selectively the partially hydrogenated product, 1,2,3,4-tetrahydroquinoline. Density functional theory (DFT) calculations show that the hydride coverage of the Rh NPs plays a key role in the adsorption modes of quinoline and 1,2,3,4-tetrahydroquinoline on the surface of the NPs, and that these adsorption modes are modulated by the presence of fullerene C60, thus affecting the activity and selectivity obtained with this rhodium based catalyst.
Luo, Zhishan,Min, Yuanyuan,Nechiyil, Divya,Bacsa, Wolfgang,Tison, Yann,Martinez, Hervé,Lecante, Pierre,Gerber, Iann C.,Serp, Philippe,Axet, M. Rosa
p. 6884 - 6898
(2019/12/26)

Titanium(III)-Oxo Clusters in a Metal-Organic Framework Support Single-Site Co(II)-Hydride Catalysts for Arene Hydrogenation
Titania (TiO2) is widely used in the chemical industry as an efficacious catalyst support, benefiting from its unique strong metal-support interaction. Many proposals have been made to rationalize this effect at the macroscopic level, yet the underlying molecular mechanism is not understood due to the presence of multiple catalytic species on the TiO2 surface. This challenge can be addressed with metal-organic frameworks (MOFs) featuring well-defined metal oxo/hydroxo clusters for supporting single-site catalysts. Herein we report that the Ti8(μ2-O)8(μ2-OH)4 node of the Ti-BDC MOF (MIL-125) provides a single-site model of the classical TiO2 support to enable CoII-hydride-catalyzed arene hydrogenation. The catalytic activity of the supported CoII-hydride is strongly dependent on the reduction of the Ti-oxo cluster, definitively proving the pivotal role of TiIII in the performance of the supported catalyst. This work thus provides a molecularly precise model of Ti-oxo clusters for understating the strong metal-support interaction of TiO2-supported heterogeneous catalysts.
Ji, Pengfei,Song, Yang,Drake, Tasha,Veroneau, Samuel S.,Lin, Zekai,Pan, Xiandao,Lin, Wenbin
p. 433 - 440
(2018/01/17)

Selective hydrogenation of quinolines into 1,2,3,4-tetrahydroquinolines over a nitrogen-doped carbon-supported Pd catalyst
In this study, we have developed a sustainable method for the hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines under mild conditions over a nitrogen-doped carbon-supported Pd catalyst with abundant porous structures (abbreviated as Pd/CN). The mesoporous structure of the nitrogen-doped carbon support was prepared by the pyrolysis of glucose and melamine using eutectic salts of KCl and ZnCl2 as the porogen. Due to the high nitrogen content in the support, Pd nanoparticles were homogeneously dispersed on the surface of nitrogen-doped carbon materials with an ultra-small size of 1.9 nm in a narrow size distribution. The as-prepared Pd/CN catalyst showed high catalytic activity towards the hydrogenation of quinolines at 50 °C and 20 bar H2, affording the corresponding 1,2,3,4-tetrahydroquinolines with yields in the range of 86.6-97.8%. More importantly, the Pd/CN catalyst was highly stable without the loss of its catalytic activity during the recycling experiments. The use of renewable resources to prepare the catalyst makes this method promising for the sustainable 1,2,3,4-tetrahydroquinolines from the hydrogenation of quinolines.
Ren, Yongshen,Wang, Yanxin,Li, Xun,Zhang, Zehui,Chi, Quan
p. 16694 - 16702
(2018/10/23)

NHC-stabilised Rh nanoparticles: Surface study and application in the catalytic hydrogenation of aromatic substrates
New Rh-NPs stabilised by N-Heterocyclic Carbenes (NHC) were synthesized by decomposition of [Rh(η3-C3H5)3] under H2 atmosphere and fully characterized. Surface studies by FT-IR and NMR spectroscopy employing isotopically labelled ligands were also performed. The Rh0.2 NPs are active catalysts in the reduction of various aromatic substrates. In the reduction of phenol, high selectivities to cyclohexanone or cyclohexanol were obtained depending on the reaction conditions. However, this catalytic system exhibited much lower activity in the hydrogenation of substituted phenols. Pyridine was easily hydrogenated under mild conditions and interestingly, the hydrogenation of 4-methyl and 4-trifluoromethylpyridine resulted slower than that of 2-methylpyridine. The hydrogenation of 1-(pyridin-2-yl)propan-2-one provided the β-enaminone 13a in high yield as a consequence of the partial reduction of the pyridine ring followed by isomerization. Quinoline could be either partially hydrogenated to 1,2,3,4-tetrahydroquinoline or fully reduced to decahydroquinoline by adjusting the reaction conditions.
Martinez-Espinar, Francisco,Blondeau, Pascal,Nolis, Pau,Chaudret, Bruno,Claver, Carmen,Castillón, Sergio,Godard, Cyril
p. 113 - 127
(2017/09/08)

Acceptorless dehydrogenation of N-heterocycles by supported Pt catalysts
Pt metal nanoparticles loaded on various supports and carbon-supported various metal catalysts are tested for dehydrogenation of 6-methyl-1,2,3,4- tetrahydroquinoline to 6-methyl-quinoline under oxidant-free conditions. In the 20 types of the catalysts screened, carbon-supported Pt catalyst (Pt/C) shows the highest activity. Pt/C is reusable after the reaction and is effective for dehydrogenation of various N- heterocycles (tetrahydroquinolines and indoline). Pt/C is also effective for hydrogenation of quinoline under 3 bar H2. The results demonstrate that this catalytic method may be useful for an organic hidride–based hydrogen storage system.
Moromi, Sondomoyee K.,Siddiki,Kon, Kenichi,Toyao, Takashi,Shimizu, Ken-ichi
p. 507 - 511
(2016/12/09)

Enzyme Cascades in Whole Cells for the Synthesis of Chiral Cyclic Amines
The increasing diversity of reactions mediated by biocatalysts has led to development of multistep in vitro enzyme cascades, taking advantage of generally compatible reaction conditions. The construction of pathways within single whole cell systems is much less explored, yet has many advantages. Herein we report the generation of a successful whole cell de novo enzyme cascade for the diastereoselective and/or enantioselective conversion of simple, linear keto acids into valuable cyclic amine products. The pathway starts with carboxylic acid reduction that triggers a transamination, imine formation, and subsequent imine reduction. Construction and optimization of the system was achieved by standard genetic manipulation and the cascade required only starting material, amine donor, and whole cell catalyst with cofactors provided internally by glucose metabolism. A panel of synthetic keto acids provided access to piperidines in high conversions (up to 93%) and enantiomeric excess (up to 93%).
Hepworth, Lorna J.,France, Scott P.,Hussain, Shahed,Both, Peter,Turner, Nicholas J.,Flitsch, Sabine L.
p. 2920 - 2925
(2017/05/31)

Preparation and characterization of NiW supported on Al-modified MCM-48 catalyst and its high hydrodenitrogenation activity and stability
Al-containing MCM-48 with different Si/Al ratios and aluminum free MCM-48 materials were successfully prepared with hexadecyl trimethyl ammonium bromide (CTAB) and poly(ethylene oxide) poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (P123) as a co-template. A series of characterizations show that both the supports and the NiW supported catalysts are highly ordered. The acid strength of the supports is enhanced when Al is introduced and when its content is increased. The acid amount and strength is further improved by supporting the NiW species. The oxide precursors show a high degree of sulfidation under mild sulfidation conditions. The activity of the Al-modified catalysts for quinoline hydrodenitrogenation (HDN) is much higher than that of aluminum free NiW/MCM-48 and NiW/γ-Al2O3 catalysts. The addition of CS2 to the feed could boost the conversion of quinoline HDN and change the product distribution due to modification of the active site distribution of hydrogenation and C-N bond cleavage. Moreover, the stability of the resulting catalysts was also investigated, and no dramatic decrease in HDN conversion was observed in 960 h, which suggests that they could be candidates for industrial HDN catalysts.
Shao, Mingqiang,Cui, Haitao,Guo, Shaoqing,Zhao, Liangfu,Tan, Yisheng
p. 61747 - 61757
(2016/07/11)

Cobalt Encapsulated in N-Doped Graphene Layers: An Efficient and Stable Catalyst for Hydrogenation of Quinoline Compounds
Porous nitrogen-doped graphene layers encapsulating cobalt nanoparticles (NPs) were prepared by the direct pyrolysis process. The resulting hybrids catalyze the hydrogenation of diverse quinoline compounds to access the corresponding tetrahydro derivatives (THQs), important molecules present in fine and bulk chemicals. Near-quantitative yields of the corresponding THQs were obtained under optimized conditions. Notably, various useful substituted quinolines and other biologically important N-heteroarenes are also viable. The enhanced stability of the catalyst is ascribed to the encapsulation structure, which can enormously reduce the extent of leaching of base metals and protect metal NPs from growing larger. The achieved success in the encapsulation of metal NPs within graphene layers opens an avenue for the design of highly active and reusable heterogeneous catalysts for more challenging molecules.
Wei, Zhongzhe,Chen, Yiqing,Wang, Jing,Su, Diefeng,Tang, Minghui,Mao, Shanjun,Wang, Yong
p. 5816 - 5822
(2016/09/09)

Support effect on conversion of quinoline over ReS2 catalyst
The conversion of quinoline over ReS2 supported on γ-Al2O3, SiO2, ZrO2 and TiO2 catalysts in a batch reactor at 300°C and 5 MPa of hydrogen pressure was studied. The catalysts were prepared by wet impregnation with a loading of 1.5 atoms of Re per nm2 of support. The catalysts were characterized by N2 adsorption, X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD). The Re(x)/supports catalysts displayed high activities for the conversion of quinoline, although negligible formation of N-free compounds (hydrodenitrogenation) were observed. The intrinsic activities of ReS2 were modified by the support decreased in the order: Re/TiO2 > Re/ZrO2 > Re/SiO2 > Re/γ-Al2O3. The highest activity displayed by the Re/TiO2 catalyst was correlated with the Re dispersion and formation of ReS2 species. Meanwhile, the lower conversion of quinoline over the Re/ZrO2, Re/SiO2 and Re/γ-Al2O3 catalysts was related to the combined effect of the textural properties of catalysts and the formation of ReS(2-x) species on the supports.
Bassi,Villarroel,Gil-Llambias,Baeza,García-Fierro,Martínez,Olivera,Leiva,Escalona
p. 3170 - 3176
(2017/02/05)

Tuning the chemoselective hydrogenation of aromatic ketones, aromatic aldehydes and quinolines catalyzed by phosphine functionalized ionic liquid stabilized ruthenium nanoparticles
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.
Jiang, He-Yan,Zheng, Xu-Xu
p. 3728 - 3734
(2015/07/07)

Selective Catalytic Hydrogenation of Heteroarenes with N-Graphene-Modified Cobalt Nanoparticles (Co3O4-Co/NGratα-Al2O3)
Cobalt oxide/cobalt-based nanoparticles featuring a core-shell structure and nitrogen-doped graphene layers on alumina are obtained by pyrolysis of Co(OAc)2/phenanthroline. The resulting core-shell material (Co3O4-Co/NGratα-Al2O3) was successfully applied in the catalytic hydrogenation of a variety of N-heteroarenes including quinolines, acridines, benzo[h], and 1,5-naphthyridine as well as unprotected indoles. The peculiar structure of the novel heterogeneous catalyst enables activation of molecular hydrogen at comparably low temperature. Both high activity and selectivity were achieved in these hydrogenation processes, to give important building blocks for bioactive compounds as well as the pharmaceutical industry.
Chen, Feng,Surkus, Annette-Enrica,He, Lin,Pohl, Marga-Martina,Radnik, J?rg,Topf, Christoph,Junge, Kathrin,Beller, Matthias
supporting information
p. 11718 - 11724
(2015/09/28)

γ-Al2O3-supported and unsupported (Ni)MoS 2 for the hydrodenitrogenation of quinoline in the presence of dibenzothiophene
Supported MoS2/γ-Al2O3 and Ni-MoS2/γ-Al2O3 as well as unsupported Ni-MoS2 were investigated in the hydrodenitrogenation (HDN) of quinoline in the presence of dibenzothiophene (DBT). The supported oxide catalyst precursors had a well-dispersed amorphous polymolybdate structure that led to the formation of a highly dispersed sulfide phase. In contrast, the unsupported catalyst precursor consisted of a mixture of nickel molybdate and ammonium nickel molybdate phases that formed stacked sulfide slabs after sulfidation. On all catalysts, the reaction pathway for the removal of N in quinoline HDN mainly followed the sequence quinoline→1,2,3,4- tetrahydroquinoline→decahydroquinoline→propylcyclohexylamine→ propylcyclohexene→propylcyclohexane. The hydrodesulfurization of DBT proceeded mainly by direct desulfurization towards biphenyl. For both processes, the activity increased in the order MoS2/γ-Al 2O32/unsupported2/γ-Al2O3. The promotion of the MoS 2 phase with Ni enhances the activity of the unsupported catalyst to a greater extent than the supported one. However, the multiply stacked unsupported Ni-MoS2 exhibited lower rates than Ni-MoS 2/γ-Al2O3 because of its lower dispersion. I want to break free (from your nitrogen): Ni and Al 2O3 exert particular effects on the physicochemical and kinetic features of molybdenum oxide species and the corresponding MoS 2 phase. The support maximizes the concentration of active sites, whereas the promoter changes their intrinsic activity. In turn, the support also influences the promotion mechanism. Copyright
Hein, Jennifer,Hrabar, Ana,Jentys, Andreas,Gutierrez, Oliver Y.,Lercher, Johannes A.
p. 485 - 499
(2014/03/21)

Competitive hydrodesulfurization of dibenzothiophene and hydrodenitrogenation of quinoline over unsupported MoS2 catalyst
The hydrodesulfurization of dibenzothiophene and the hydrodenitrogenation of quinoline were investigated both individually and simultaneously as a mixture over an unsupported synthetic MoS2 catalyst. The reactions were carried out in a batch system under 3 MPa H2 at 340 C. Investigations toward the effect of H2S on the hydrodenitrogenation reaction of quinoline revealed that H2S promoted the transformation of 1,2,3,4-tetrahydroquinoline (THQ1) to ortho-propylaniline (OPA), but had a considerable adverse impact on the transformation of OPA to propylbenzene and its derivatives (C9 products). The hydrodesulfurization of dibenzothiophene proceeded predominantly through a hydrogenation pathway to give cyclohexylbenzene. The hydrodesulfurization of dibenzothiophene was found to be completely inhibited during the initial stages of the reaction, when quinoline was added into the feedstock. The inhibition of the reaction persisted until the quinoline was transformed to a sufficiently low level. Thereafter, the hydrodesulfurization of dibenzothiophene recovered and the reaction proceeded with only moderate inhibition. In contrast, the hydrodenitrogenation of quinoline was significantly enhanced by the presence of dibenzothiophene in the reaction feedstock. The THQ1 and C9 products were the main species obtained from the hydrodenitrogenation reaction of quinoline. The presence of dibenzothiophene enhanced the activity and selectivity toward C9 productions. These results suggested that at least two types of active site were involved in the reaction. Dibenzothiophene could interact with distinct coordinative unsaturated sites, and this could stabilize and increase the acidity of the potential active sites assumed to be responsible for the hydrodenitrogenation reactions.
Farag, Hamdy,Kishida, Masahiro,Al-Megren, Hamid
p. 173 - 182
(2013/11/19)

Mild hydrogenation of quinoline to decahydroquinoline over rhodium nanoparticles entrapped in aluminum oxy-hydroxide
An Rh/AlO(OH) catalyst was prepared by a sol-gel method. This catalyst showed an excellent catalytic performance for the complete hydrogenation of quinoline to decahydroquinoline at relatively mild conditions. The growth of Rh-particle size and the decrease in the number of surface hydroxyl groups during heat treatment resulted in a significant decrease in catalytic properties. The excellent catalytic performance of the fresh Rh/AlO(OH) was attributed to the cooperation between the hydroxyl groups on the support and on the active metal centers.
Fan, Guang-Yin,Wu, Jie
p. 81 - 85
(2013/03/14)

NanoRu@hectorite: A heterogeneous catalyst with switchable selectivity for the hydrogenation of quinoline Dedicated to Professor Irina Petrovna Beletskaya in recognition of her contributions to the field of metal-catalysed reactions.
A versatile nano-structured catalyst composed of ruthenium nanoparticles intercalated in hectorite (nanoRu@hectorite) catalyzes the hydrogenation of quinoline (100 C, 30-60 bar H2) with switchable selectivity: In water, 1,2,3,4-tetrahydroquinoline is formed with yields >99%, while in cyclohexane the fully hydrogenated decahydroquinoline is obtained with yields >99%, the mean turnover frequencies being 222 h-1 and 89 h -1, respectively. The reaction in cyclohexane proceeds via both intermediates, 1,2,3,4-tetrahydroquinoline and 5,6,7,8-tetrahydroquinoline.
Sun, Bing,Khan, Farooq-Ahmad,Vallat, Armelle,Süss-Fink, Georg
p. 310 - 314
(2013/09/12)

Hydrogenation of arenes and N-heteroaromatic compounds over ruthenium nanoparticles on poly(4-vinylpyridine): A versatile catalyst operating by a substrate-dependent dual site mechanism
A nanostructured catalyst composed of Ru nanoparticles immobilized on poly(4-vinylpyridine) (PVPy) has been synthesized by NaBH4 reduction of RuCl3·3H2O in the presence of the polymer in methanol at room temperature. TEM measurements show well-dispersed Ru nanoparticles with an average diameter of 3.1 nm. Both powder XRD patterns and XPS data indicate that the Ru particles are predominantly in the zerovalent state. The new catalyst is efficient for the hydrogenation of a wide variety of aromatic hydrocarbons and N-heteroaromatic compounds representative of components of petroleum-derived fuels. The experimental data indicate the existence of two distinct active sites in the nanostructure that lead to two parallel hydrogenation pathways, one for simple aromatics involving conventional homolytic hydrogen splitting on Ru and a second one for N-heteroaromatics taking place via a novel heterolytic hydrogen activation on the catalyst surface, assisted by the basic pyridine groups of the support.
Fang, Minfeng,MacHalaba, Nataliya,Sanchez-Delgado, Roberto A.
experimental part
p. 10621 - 10632
(2011/11/29)

Studies concerning the electrophilic amino-alkene cyclisation for the synthesis of bicyclic amines
The bromination of a series of cyclohexenyl substituted secondary amines 1a-i has been investigated using Br2, PHT and NBS. In the case of Br2 and NBS the secondary amines preferentially undergo N-bromination. In contrast, PHT cleanly affords the products of alkene dibromination. In the case of Br2 the N-bromo species then give the products of alkene dibromination, albeit less efficiently. On subsequent treatment with K2CO3 these dibromides form the corresponding hexahydroindoles 2a-h and octahydroquinoline 2i. The presence of an N-substituent bearing a stereogenic centre (1h and 1i) was studied and the products 2h and 2i were isolated with no diastereoselectivity. When NBS was used a novel cyclisation, forming bromo-substituted octahydroindoles 9a,b and d, was observed. In relation to this sequence it was shown that these products were not intermediates in the former Br2/PHT processes and that the reaction only proceeded in the presence of the succinimide by-product of N-bromination.
Klein, Johannes E. M. N.,Mueller-Bunz, Helge,Evans, Paul
experimental part
p. 986 - 995
(2009/05/30)

Rhodium nanoparticles entrapped in boehmite nanofibers: Recyclable catalyst for arene hydrogenation under mild conditions
A new recyclable rhodium catalyst was synthesized by a simple procedure from readily available reagents, which showed high activities in the hydrogenation of various arenes under 1 atm H2 at room temperature. The Royal Society of Chemistry 2005.
Park, In Soo,Kwon, Min Serk,Kim, Namdu,Lee, Jae Sung,Kang, Kyung Yeon,Park, Jaiwook
p. 5667 - 5669
(2007/10/03)

Solvent dependent regioselective hydrogenation of substituted quinolines
Various substituted quinolines have been reduced under H2 using Rh/Al2O3. Using methanol as solvent leads selectively to the 1,2,3,4-tetrahydroquinoline derivatives whereas in hexafluoroisopropanol the decahydro compounds are obtained.
Fache, Fabienne
p. 2827 - 2829
(2007/10/03)

A comparison between silica-immobilized ruthenium(II) single sites and silica-supported ruthenium nanoparticles in the catalytic hydrogenation of model hetero- and polyaromatics contained in raw oil materials
HDS and HDN are very important hydrotreating reactions that remove sulfur and nitrogen from fossil fuels where they are contained in various organic compounds, which include polyaromatic heterocycles, aliphatic and aromatic thiols and amines, thioethers, disulfides, and nitriles. A comparative study of the hydrogenation of various heterocycles, model compounds in raw oil materials, by either Ru(II) complex immobilized on mesoporous silica or Ru(0) nanoparticles deposited on the same support was conducted. The single-site catalyst contained the molecular precursor [Ru(NCMe)3(sulphos)](OSO2 CF3) tethered to partially dehydroxylated high-surface-area silica through hydrogen bonds between silanol groups of the support and SO3- groups from the sulphos ligand [-O3S(C6H4) CH2C(CH2PPh2)3] and the triflate counter anion. The heterocycles (benzo[b]thiophene, quinoline, indole, acridine) were hydrogenated to cyclic thioethers or amines. Ru(II)-based catalysts were much more efficient for the hydrogenation of S-heterocycles than for N-heterocycles.
Bianchini, Claudio,Dal Santo, Vladimiro,Meli, Andrea,Moneti, Simonetta,Moreno, Marta,Oberhauser, Werner,Psaro, Rinaldo,Sordelli, Laura,Vizza, Francesco
p. 47 - 62
(2007/10/03)

HDN activities of methyl-substituted quinolines
Catalytic hydrotreating has become an important process for removal of sulfur and nitrogen from petroleum due to increasing environmental constraints. The HDN reactivities of quinoline (Q) and several methyl-substituted quinolines (MQ) were determined over a NiMo/Al2O3 catalyst and a CoMo/Al2O3 catalyst using a fixed-bed reactor at 613 K and 3.1MPa. For HDN activity, methyl groups on the aromatic ring gave about the same conversion as for Q, while methyl groups on the N ring gave considerably lower HDN conversions, except for 2-MQ, which was higher. Results were essentially the same for the NiMo and CoMo catalysts. All MQs and Q rapidly reached equilibrium between Q and THQ1 (and their respective methyl analogs). Total and HDN activities were roughly related to their respective equilibria, except for 2-MQ, in which the methyl group provided a positive influence. The rate constants for the formation of o-propylaniline from THQ1 correlated well with the electrostatic potential on the N atom of the respective THQl.
Kim,Simons, Jack,Massoth
p. 201 - 206
(2007/10/03)

2-aminopyridine derivatives and combinatorial libraries thereof
The present invention relates to novel 2-aminopyridine derivative compounds of the following formula: wherein R1to R5have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminopyridine derivative compounds.
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(2008/06/13)

Mechanism of the hydrodenitrogenation of quinoline over NiMo(P)/Al2O3 catalysts
The hydrodenitrogenation (HDN) of quinoline and its reaction intermediates was studied over NiMo(P)/Al2O3 catalysts. Phosphorus exhibited a promotional effect on the HDN of quinoline and ortho-propylaniline and a negative effect on t
Jian,Prins
p. 18 - 27
(2007/10/03)

PEPTIDE COMPOUNDS DERIVED FROM BORONIC ACID
A compound of formula (I): STR1 in which: R 1 represents hydrogen or acyl, alkyl, benzyl, alkoxycarbonyl, benzyloxycarbonyl, phenoxycarbonyl, 5-[(dimethyl)amino]naphthylsulfonyl, alkoxycarbonylmethyl or carboxymethyl,R 2 represents hydrogen or phenyl, substituted or unsubstituted benzyl, 3-thienylmethyl, 2-pyridylmethyl, diphenylmethyl, fluorenyl, naphthylmethyl, benzocyclobutyl, (dicyclopropylmethyl)methyl, indanyl or (C 3-C 7 cycloalkyl)methyl,R' 2 represents hydrogen or benzylor alternativelyR 2 and R'. sub.2 together represent C 6 H 5--CH=,R. sub.3 represents substituted alkyl or guanidinophenyl, amidinophenyl, aminophenyl, guanidinobenzyl, amidinobenzyl, aminobenzyl or cycloalkyl, R 4 and R 5 each represent hydrogen or alkyl, or STR2 forms a boronic ester of pinanediol, A represents any one of the groups as defined in the description.Medicinal products.
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(2008/06/13)

α-alkylation and stereochemistry of cis- and trans-decahydroquinolines mediated by the formamidine and boc activating groups. Synthesis of pumiliotoxin C 1
cis- and trans-decahydroquinolines, as their t-Boc and formamidine derivatives, have been metalated and alkylated. The former gives mainly axial alkylation whereas the latter gives equatorial alkylation in the trans series. For the cis series, the t-Boc derivative gives essentially pure equatorial alkylation as does the formamidine derivative. Several electron-transfer processes occur simultaneously with the ionic alkylation, and this can be altered by use of pentynylcopper or HMPA. Furthermore, cuprates, when employed, gave good yields of alkylation product via radical pathways, but the stereochemistry suffered. A synthesis of the poison dart frog secretion, pumiliotoxin C, has been accomplished using these alkylation techniques.
Meyers,Milot, Guy
p. 6652 - 6660
(2007/10/02)

Preparation of 2-(3-aminopropyl)-cycloalkylamines
A process for the preparation of a 2-(3-aminopropyl)-cycloalkylamine of the general formula I STR1 in which the subscript n is an integer from 1 to 4, from a 2-(2-cyanoethyl)-cycloalkanone of the general formula II STR2 in which the subscript n has the meaning stated, wherein the following stages are carried out in discrete reaction chambers: a) the 2-(2-cyanoethyl)-cycloalkanone of formula II is reacted in a first reaction chamber with excess ammonia over an acidic heterogeneous catalyst at a temperature from 20° to 150° C. and a pressure of from 15 to 500 bar, and b) in a second reaction chamber, the reaction product from stage a) is hydrogenated at a temperature of from 60° to 150° C. and a pressure of from 50 to 300 bar in the presence of excess ammonia over a catalyst containing cobalt, nickel, ruthenium, and/or some other noble metal, which catalyst optionally contains a basic component or is supported on neutral or basic supporting material.
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(2008/06/13)

A Stereoselective Synthesis of (+/-)-trans-Cycloalkanopiperidines and Cycloalkanopyrrolidines via Hydroboration
A highly stereoselective synthesis of trans-cycloalkanopiperidines and cycloalkanopyrrolidines has been achieved via hydroboration of bromocycloalkenes with dichloroboranes.The intermediate bromocycloalkylboronic acids were converted into azidocycloalkylboronates.Addition of two equivalents of boron trichloride in dichloromethane generated dichloroboranes which, by an intramolecular cyclisation gave intermediates 11.These can be readily hydrolyzed to get the corresponding important nitrogen heterocycles in good yields and excellent stereochemical purities.
Brown, Herbert C.,Salunkhe, Ashok M.
p. 1265 - 1268
(2007/10/02)

HYDRODENITROGENATION OF QUINOLINE AND PHENANTHRIDINE IN THE PRESENCE OF 2,6-DIETHYLANILINE AND HYDROGEN SULFIDE OVER MOLYBDENUM AND NICKEL-MOLYBDENUM SULFIDES SUPPORTED ON ZIRCONIA, TITANIA, NICKEL- AND MAGNESIUM-ALUMINATES
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Moreau, C.,Bekakra, L.,Geneste, P.,Olive, J. L.,Duchet, J. C.,et al.
p. 841 - 848
(2007/10/02)

KINETIC STUDY OF THE EFFECT OF PHOSPHORUS IN THE HDN OF 5-TETRAHYDROQUINOLINE OVER Ni-MoS/γ-Al2O3 CATALYSTS
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Rico Cerdo, J. L.,Prins, R.
p. 815 - 822
(2007/10/02)

Hydrogenation Pathway of Quinolines over Raney Nickel and Ru/C
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.
Okazaki, Hiroshi,Onishi, Kiyotaka,Soeda, Mahito,Ikefuji, Yoshio,Tamura, Ryuji,Mochida, Isao
p. 3167 - 3174
(2007/10/02)

TRANSFORMATION OF QUINOLINES AND ANILINES OVER NiMo-Al2O3 CATALYSTS
The decomposition of nitrogen-containing compounds: 1,2,3,4-tetrahydroquinoline, 6-methylquinoline, decahydroquinoline, orthopropylaniline and 2,6-diethyl,1-aniline, was studied at 623 K, 7 MPa in a continuous flow microreactor over two commercial nickel-molybdenum-alumina catalysts, (HR346 and HR348, Procatalyse).Decahydroquinoline was found to react very rapidly under the conditions of 1,2,3,4-tetrahydroquinoline hydrodenitrogenation.The simultaneous transformations of quinoline and aniline showed that the aniline transformation was inhibited by the quinolines.However the inhibiting effect was much less significant with HR348 which also happens to be more active in aniline transformation.
Perot, G.,Brunet, S.,Canaff, C.,Toulhoat, H.
p. 865 - 870
(2007/10/02)

SYNTHESIS OF ORGANO DIETHYL PHOSPHATES CONTAINING NITROGENOUS HETEROCYCLES
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Karimov, D. T.,Dalimov, D. N.,Abduvakhabov, A. A.,Godovikov, N. N.
p. 1049 - 1052
(2007/10/02)

ENAMINE CHEMISTRY-XXIV. SYNTHESIS, THIATION, AND REDUCTION OF LACTAMS
Enamines, 1, prepared from cyclohexanones or cyclopentanones are reacted with acrylamide to give lactams, the condensed 2-piperidones, 2.Ethyl 2-(1-pyrrolidinyl)-2-cyclohexene-1-propanoate, 3, when treated with primary amines, produces the corresponding N-substituted 2-piperidones, 4.Ethyl 2-(1-pyrrolidinyl)-2-cyclohexene-1-ethanoates and ethyl 2-(1-pyrrolidinyl)-2-cyclopentene-1-ethanoate, 5, react with primary amines to give condensed N-substituted 2-pyrrolidones, 6, and non-cyclic imines, 7.The starting enamines , 1, treated with 2-bromo acetamides only afford the N-alkylated compounds, 8 (2-pyrrolidino acetamides), and the regioselectivity of this reaction is rationalized in terms of the HSAB-principle.Compound 1 undergoes an exchange reaction (aminolysis) when reacted with primary amines to give the imines 9.Thiation of the lactams 2 and 6 with the Lawesson reagent (LR), affords the corresponding thiolactams, 10.Reduction of the lactams and thiolactams, 2, 6, and 10 by LAH gives the imines, 11, and the enamines, 16.Further reduction of 11 (LAH) affords the saturated amines, 15.The stereochemistry for the formation of 15 is discussed using the torsion angle notation and the principal of least torsional distortion.In a one-pot reaction using LAH-acetic anhydride the lactams, 2, and the thiolactams, 10, are transformed into the enamides, 14.Compound 14 was also obtained from 11 by direct acetylation with acetic anhydride in the presence of triethylamine.
El-Barbary, A. A.,Carlsson, S.,Lawesson, S.-O.
p. 405 - 412
(2007/10/02)