- Fine tuning of Pd0 nanoparticle formation on hydroxyapatite and its application for regioselective quinoline hydrogenation
-
Fine control of the formation of Pd0 nanoparticles with diameters between 1 and 1.5nm on hydroxyapatite (HAP) was achieved by adjusting the temperature at which the PdII species on the HAP surface (Pd IIHAP) was reduced in the presence of 1 atm of molecular hydrogen. The HAP-supported Pd0 nanoparticles (Pd0HAP) having an average diameter of 1.5 nm exhibited significantly high catalytic activity for the regioselective hydrogenation of quinolines to the corresponding 1,2,3,4-tetrahydroquinolines under mild reaction conditions. Moreover, the Pd0HAP catalyst was reusable without appreciable loss of its high catalytic activity or selectivity.
- Hashimoto, Norifumi,Takahashi, Yusuke,Hara, Takayoshi,Shimazu, Shogo,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
-
Read Online
- Selective reduction of condensed N-heterocycles using water as a solvent and a hydrogen source
-
The reduction of unprotected indoles and quinolines is described using water as a hydrogen source. The method is based on the application of a RANEY type Ni-Al alloy in an aqueous medium. During the reaction the Al content of the alloy, used as reductants, reacts with water in situ providing hydrogen and a RANEY Ni catalyst, thus the alloy serves as a hydrogen generator as well as a hydrogenation catalyst. The simplicity and efficacy of the method are illustrated by the selective reduction of a variety of substituted indoles and quinolines to indolines and tetrahydroquinolines, respectively.
- Cho, Hyejin,T?r?k, Fanni,T?r?k, Béla
-
-
Read Online
- Regio- and chemoselective transfer hydrogenation of quinolines catalyzed by a Cp*Ir complex
-
An efficient method for the transfer hydrogenation of quinolines catalyzed by a Cp*Ir complex was developed. A variety of 1,2,3,4-tetrahydroquinolines were obtained by regio- and chemoselective transfer hydrogenation of quinolines using 2-propanol as a hydrogen source.
- Fujita, Ken-Ichi,Kitatsuji, Chihiro,Furukawa, Shigetoyo,Yamaguchi, Ryohei
-
-
Read Online
- Utilization of renewable formic acid from lignocellulosic biomass for the selective hydrogenation and/or N-methylation
-
Lignocellulosic biomass is one of the most abundant renewable sources in nature. Herein, we have developed the utilization of renewable formic acid from lignocellulosic biomass as a hydrogen source and a carbon source for the selective hydrogenation and further N-methylation of various quinolines and the derivatives, various indoles under mild conditions in high efficiencies. N-methylation of various anilines is also developed. Mechanistic studies indicate that the hydrogenation occurs via a transfer hydrogenation pathway.
- Zhou, Chao-Zheng,Zhao, Yu-Rou,Tan, Fang-Fang,Guo, Yan-Jun,Li, Yang
-
-
Read Online
- An unusual chemoselective hydrogenation of quinoline compounds using supported gold catalysts
-
The pursuit of modern sustainable chemistry has stimulated the development of innovative catalytic processes that enable chemical transformations to be performed under mild and clean conditions with high efficiency. Herein, we report that gold nanoparticles supported on TiO2 catalyze the chemoselective hydrogenation of functionalized quinolines with H2 under mild reaction conditions. Our results point toward an unexpected role for quinolines in gold-mediated hydrogenation reactions, namely that of promoter; this is in stark contrast to what prevails in the traditional noble metal Pd-, Pt-, and Ru-based catalyst systems, in which quinolines and their derivatives typically act as poisons. As a result of the remarkable promotional effect of quinoline molecules to H2 activation over supported gold, the transformation can proceed smoothly under very mild conditions (even at temperatures as low as 25 °C). Of practical significance is that various synthetically useful functional groups including halogens, ketone, and olefin remain intact during the hydrogenation of quinolines. Moreover, the protocol also shows promise for the regiospecific hydrogenation of the heterocyclic ring of a variety of other biologically important heteroaromatic nitrogen compounds, such as isoquinoline, acridine, and 7,8-benzoquinoline, in a facile manner. Apart from its importance in catalytic hydrogenation, we believe that this intriguing self-promoted effect by reactant molecules may have fundamental implications for the broad field of gold catalysis and form the basis for development of new catalytic procedures for other key transformations.
- Ren, Dong,He, Lin,Yu, Lei,Ding, Ran-Sheng,Liu, Yong-Mei,Cao, Yong,He, He-Yong,Fan, Kang-Nian
-
p. 17592 - 17598,7
(2012)
-
Read Online
- High efficient iron-catalyzed transfer hydrogenation of quinolines with Hantzsch ester as hydrogen source under mild conditions
-
A highly efficient transfer hydrogenation of quinolines with Hantzsch ester as hydrogen source in the presence of 1 mol% Fe(OTf)2 under mild conditions has been developed. A series of substituted 1,2,3,4-tetrahydroquinoline derivatives were afforded in excellent yields with good functional group tolerance.
- He, Renke,Cui, Peng,Pi, Danwei,Sun, Yan,Zhou, Haifeng
-
-
Read Online
- Reduction of quinolines to 1,2,3,4-tetrahydro derivatives employing a combination of NaCNBH3 and BF3.OEt2
-
A regiospecific reduction of quinolines (and 1,10-phenanthroline) into the corresponding 1,2,3,4-tetrahydro derivatives using a combination of sodium cyanoborohydride and boron trifluoride etherate in refluxing methanol is described. Under the same conditions indole and acridine reduced to the corresponding dihydroderivatives, whereas acyl group transfer from oxygen to nitrogen atom is also noticed in the case of 8-acyloxyquinolines.
- Srikrishna, Adusumilli,Reddy, T. Jagadeeswar,Viswajanani, Ranganathan
-
-
Read Online
- Efficient Hydrogenation of Nitrogen Heterocycles Catalyzed by Carbon-Metal Covalent Bonds-Stabilized Palladium Nanoparticles: Synergistic Effects of Particle Size and Water
-
We reveal here the first hydrogenation of nitrogen heterocycles catalyzed by carbon–metal covalent bonds-stabilized palladium nanoparticles in water under mild conditions. Using a one-phase reduction method, smaller metal–carbon covalent bond-stabilized Pd nanoparticles were prepared with a size distribution of 2.5±0.5 nm, which showed extraordinary synergistic effects with water in the catalytic hydrogenation of nitrogen heterocycles. Water was supposed to accelerate substrate absorption and synergistic activation of molecular hydrogen on the Pd nanoparticles surface. The nanosized Pd catalyst could be easily recovered and reused for 5 runs. (Figure presented.).
- Zhang, Yu,Zhu, Jie,Xia, Yun-Tao,Sun, Xiao-Tao,Wu, Lei
-
-
Read Online
- Tuning chemical compositions of bimetallic AuPd catalysts for selective catalytic hydrogenation of halogenated quinolines
-
Catalytic hydrogenation of halogenated quinolines is a longstanding challenge due to the harsh reaction conditions and disillusionary chemoselectivity owing to dehalogenation. Exploration of novel catalytic materials is still a big challenge. Herein, density functional theory calculations indicate that halogenated quinolines are selectively adsorbed on the Au surface via the nitrogen atom in the tilted orientation and on Pd via the quinoline ring in the flat orientation. In the tilted orientation, the C-Cl bond is away from the surface of catalysts, which can avoid the hydrogenation of the C-Cl bond by the surface activated hydrogen species. A series of Au1?xPdx bimetallic catalysts were deposited on CeO2 nanorods by a facile electroless chemical deposition method. The Au1?xPdx catalysts with low Pd content delivered enhanced activity and improved chemoselectivity for the hydrogenation of halogenated quinolines. Highly dispersed Pd in the Au matrix of bimetallic catalysts with low Pd content triggers hydrogen activation on Pd sites and leads to the selective adsorption of halogenated quinolines on Au sites in the tilted orientation. The generated active hydrogen species can diffuse from Pd to Au sites for the hydrogenation of the tilted halogenated quinolines, resulting in suppressed dehalogenation and high chemoselectivity to the expected products.
- Zhang, Sai,Xia, Zhaoming,Ni, Ting,Zhang, Huan,Wu, Chao,Qu, Yongquan
-
-
Read Online
- Rational design, synthesis, anti-HIV-1 RT and antimicrobial activity of novel 3-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)-1-(piperazin-1-yl)propan-1-one derivatives
-
In the present study, fifteen novel 3-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)-1-(piperazin-1-yl)propan-1-one (6a-o) derivatives were designed as inhibitor of HIV-1 RT using ligand based drug design approach and in-silico evaluated for drug-likeness properties. Designed compounds were synthesized, characterized and in-vitro evaluated for RT inhibitory activity against wild HIV-1 RT strain. Among the tested compounds, four compounds (6a, 6b, 6j and 6o) exhibited significant inhibition of HIV-1 RT (IC50 ≤ 10 μg/ml). All synthesized compounds were also evaluated for anti-HIV-1 activity as well as cytotoxicity on T lymphocytes, in which compounds 6b and 6l exhibited significant anti-HIV activity (EC50 values 4.72 and 5.45 μg/ml respectively) with good safety index. Four compounds (6a, 6b, 6j and 6o) found significantly active against HIV-1 RT in the in-vitro assay were in-silico evaluated against two mutant RT strains as well as one wild strain. Further, titled compounds were evaluated for in-vitro antibacterial (Escherichia coli, Pseudomonas putida, Staphylococcus aureus and Bacillus cereus) and antifungal (Candida albicans and Aspergillus Niger) activities.
- Chander, Subhash,Wang, Ping,Ashok, Penta,Yang, Liu-Meng,Zheng, Yong-Tang,Murugesan, Sankaranarayanan
-
-
Read Online
- Geometric and electronic effects on the performance of a bifunctional Ru2P catalyst in the hydrogenation and acceptorless dehydrogenation of N-heteroarenes
-
The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N-heterocycles is a challenge. In this study, Ru2P/AC effectively promoted reversible transformations between unsaturated and saturated N-heterocycles affording yields of 98% and 99%, respectively. Moreover, a remarkable enhancement in the reusability of Ru2P/AC was observed compared with other Ru-based catalysts. According to density functional theory calculations, the superior performance of Ru2P/AC was ascribed to specific synergistic factors, namely geometric and electronic effects induced by P. P greatly reduced the large Ru-Ru ensembles and finely modified the electronic structures, leading to a low reaction barrier and high desorption ability of the catalyst, further boosting the hydrogenation and acceptorless dehydrogenation processes.
- Shao, Fangjun,Yao, Zihao,Gao, Yijing,Zhou, Qiang,Bao, Zhikang,Zhuang, Guilin,Zhong, Xing,Wu, Chuan,Wei, Zhongzhe,Wang, Jianguo
-
-
Read Online
- A robust iron catalyst for the selective hydrogenation of substituted (iso)quinolones
-
By applying N-doped carbon modified iron-based catalysts, the controlled hydrogenation of N-heteroarenes, especially (iso)quinolones, is achieved. Crucial for activity is the catalyst preparation by pyrolysis of a carbon-impregnated composite, obtained from iron(ii) acetate and N-aryliminopyridines. As demonstrated by TEM, XRD, XPS and Raman spectroscopy, the synthesized material is composed of Fe(0), Fe3C and FeNx in a N-doped carbon matrix. The decent catalytic activity of this robust and easily recyclable Fe-material allowed for the selective hydrogenation of various (iso)quinoline derivatives, even in the presence of reducible functional groups, such as nitriles, halogens, esters and amides. For a proof-of-concept, this nanostructured catalyst was implemented in the multistep synthesis of natural products and pharmaceutical lead compounds as well as modification of photoluminescent materials. As such this methodology constitutes the first heterogeneous iron-catalyzed hydrogenation of substituted (iso)quinolones with synthetic importance.
- Sahoo, Basudev,Kreyenschulte, Carsten,Agostini, Giovanni,Lund, Henrik,Bachmann, Stephan,Scalone, Michelangelo,Junge, Kathrin,Beller, Matthias
-
-
Read Online
- Highly efficient and recyclable rhodium nanoparticle catalysts for hydrogenation of quinoline and its derivatives
-
PEG-stabilized rhodium nanoparticles exhibited high activity, selectivity and recyclability for the hydrogenation of quinoline and its derivatives. The selectivity of 1,2,3,4-tetrahydroquinoline was higher than 99%. The catalysts were recycled ten times with a total turnover number of 10592, which is the highest value ever reported for quinoline.
- Niu, Mingming,Wang, Yanhua,Chen, Pu,Du, Dongjie,Jiang, Jingyang,Jin, Zilin
-
-
Read Online
- Au Nanoparticles Confined in SBA-15 as a Highly Efficient and Stable Catalyst for Hydrogenation of Quinoline to 1,2,3,4-Tetrahydroquinoline
-
Abstract: Au nanoparticles confined within the mesopores of the modified SBA-15 were obtained through adsorption-reduction method and firstly employed as chemoselective catalyst for quinoline hydrogenation. The effects of Au loadings, calcination temperature as well as structure of support on catalytic performances of Au catalysts were explored. The as-obtained 1.2percentAu@SBA-15-500 catalyst exhibited high activity, excellent selectivity towards 1,2,3,4-tetrahydroquinoline and extraordinary sintering-resistant property as high as 800?°C, which is sharp contrast to the 1.3percentAu/SiO2-500 catalyst. It also showed good recyclability and versatility for quinoline derivatives. The observed properties were assigned to small-sized Au nanoparticles and mesopores of SBA-15. Our work provides a facile and promising approach to construct metal nanocatalysts with high catalytic performance by the use of mesoporous materials. Graphic Abstract: [Figure not available: see fulltext.].
- Zhao, Jianbo,Yuan, Haifeng,Qin, Xiaomei,Tian, Kuan,Liu, Yingfan,Wei, Chengzhen,Zhang, Zhiqiang,Zhou, Liming,Fang, Shaoming
-
-
Read Online
- Ni0/Niδ+ Synergistic Catalysis on a Nanosized Ni Surface for Simultaneous Formation of C-C and C-N Bonds
-
Simultaneous formation of C-C/C-N bonds provides insight into the bottom-up synthesis of N-heterocycles. This work reports Ni0/Niδ+ synergistic catalysis on the surface of Ni nanoparticles for the highly efficient one-pot formation of C-C/C-N bonds, affording 1,2,3,4-tetrahydroquinoline and its derivatives from 2-amino benzyl alcohol and ethanol without any addition of liquor base or external hydrogen. Ni0/Niδ+ synergistic catalysis has been achieved by regulating the Ni particle size or activating the Ni surface with O2. In the dehydrogenation of -CH2-OH to -CH=O, the formation of C==C and C=N bonds via concurrent cross-condensation, and the transformation of C=C/C=N to C-C/C-N via hydrogen transfer, ethanol dehydrogenation has been found to be the rate-determining step. Reducing the Ni particle size effectively increases the number of surface Niδ+ sites, which accelerates catalytic dehydrogenation through synergistic catalysis between surface Niδ+ and Ni0 sites. The number of surface Niδ+ sites can be further increased by appropriately activating the Ni surface with O2
- Zhang, Jian,An, Zhe,Zhu, Yanru,Shu, Xin,Song, Hongyan,Jiang, Yitao,Wang, Wenlong,Xiang, Xu,Xu, Linlin,He, Jing
-
-
Read Online
- Water-involving transfer hydrogenation and dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode
-
A room-temperature electrochemical strategy for hydrogenation (deuteration) and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode is developed, which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80% Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99% yield and selectivity. The in situ generated active hydrogen atom (H*) is plausibly involved in the hydrogenation of quinoxaline, where a consecutive hydrogen radical coupled electron transfer pathway is proposed. Notably, the MoNi4 alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV, owing to its superior water dissociation ability to provide H* in alkaline media. In situ Raman tests indicate that the NiII/NiIII redox couple can promote the dehydrogenation process, representing a promising anodic alternative to low-value oxygen evolution. Impressively, electrocatalytic deuteration is easily achieved with up to 99% deuteration ratios using D2O. This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.
- Han, Shuyan,Huang, Yi,Li, Mengyang,Liu, Cuibo,Zhang, Bin
-
-
Read Online
- Regioselective reduction of quinolines and related systems to 1,2,3,4-tetrahydro derivatives with zinc borohydride
-
A simple and convenient procedure for the reduction of quinolines, isoquinoline and other related systems to the corresponding 1,2,3,4-tetrahydro derivatives has been developed in the presence of catalytic amount of N,N-dimethyl aniline under sonication.
- Ranu, Brindaban C.,Jana, Umasish,Sarkar, Arunkanti
-
-
Read Online
- A General and Highly Selective Cobalt-Catalyzed Hydrogenation of N-Heteroarenes under Mild Reaction Conditions
-
Herein, a general and efficient method for the homogeneous cobalt-catalyzed hydrogenation of N-heterocycles, under mild reaction conditions, is reported. Key to success is the use of the tetradentate ligand tris(2-(diphenylphosphino)phenyl)phosphine). This non-noble metal catalyst system allows the selective hydrogenation of heteroarenes in the presence of a broad range of other sensitive reducible groups.
- Adam, Rosa,Cabrero-Antonino, Jose R.,Spannenberg, Anke,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
-
-
Read Online
- Water-assisted one-pot synthesis of N-doped carbon supported Ru catalysts for heterogeneous catalysis
-
For the first time, a simple yet efficient water-assisted one-pot pyrolysis (WAOP) strategy was developed toin situliberate the inaccessible Ru active sites confined inside N-doped carbon. The liberated Ru/CN catalysts exhibit a 9-fold improvement in catalytic activity for quinoline hydrogenation compared with catalysts obtained from the water-free pyrolysis process, and high tolerance for selective hydrogenation of various quinolines substituted with different functional groups. We anticipate that WAOP addresses a key issue that currently plagues carbon-based catalyst synthesis and should lead to improvements in fields as diverse as chemical production and environmental protection.
- Cao, Yueling,Chen, Kai-Jie,Liu, Kangkai,Zhang, Hepeng
-
-
Read Online
- Iodine catalyzed reduction of quinolines under mild reaction conditions
-
A reduction of quinolines to synthetically versatile tetrahydroquinoline molecules with I2 and HBpin is described. In the presence of iodine (20 mol%) as a catalyst, reduction of quinolines and other N-heteroarenes proceeded readily with hydroboranes as the reducing reagents. The broad functional-group tolerance, good yields and mild reaction conditions imply high practical utility.
- Yang, Chun-Hua,Chen, Xixi,Li, Huimin,Wei, Wenbo,Yang, Zhantao,Chang, Junbiao
-
-
Read Online
- Indium as a reducing agent: Selective reduction of the heterocyclic rings in quinolines, isoquinolines and quinoxalines
-
The heterocyclic ring in quinolines, isoquinolines and quinoxalines is selectively reduced using indium metal in aqueous ethanol.
- Moody, Christopher J.,Pitts, Michael R.
-
-
Read Online
- Cobalt-catalysed transfer hydrogenation of quinolines and related heterocycles using formic acid under mild conditions
-
Herein, we report the first example of homogeneous non-noble metal-catalyzed transfer hydrogenation of N-heteroarenes. The combination of Co(BF4)2·6H2O with tris(2-(diphenylphosphino)phenyl)phosphine L1 is able to selectively reduce quinolines in the presence of other sensitive functional groups, under mild conditions, using formic acid as a hydrogen source.
- Cabrero-Antonino, Jose R.,Adam, Rosa,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
-
-
Read Online
- Tuning the Catalytic Performance of Cobalt Nanoparticles by Tungsten Doping for Efficient and Selective Hydrogenation of Quinolines under Mild Conditions
-
Non-noble bimetallic CoW nanoparticles (NPs) partially embedded in a carbon matrix (CoW@C) have been prepared by a facile hydrothermal carbon-coating methodology followed by pyrolysis under an inert atmosphere. The bimetallic NPs, constituted by a multishell core-shell structure with a metallic Co core, a W-enriched shell involving Co7W6 alloyed structures, and small WO3 patches partially covering the surface of these NPs, have been established as excellent catalysts for the selective hydrogenation of quinolines to their corresponding 1,2,3,4-tetrahydroquinolines under mild conditions of pressure and temperature. It has been found that this bimetallic catalyst displays superior catalytic performance toward the formation of the target products than the monometallic Co@C, which can be attributed to the presence of the CoW alloyed structures.
- Concepción, Patricia,Corma, Avelino,Liu, Lichen,Puche, Marta,Sorribes, Iván
-
-
Read Online
- Activation of Quinolines by Cationic Chalcogen Bond Donors
-
The application of already established as well as novel selenium- and sulfur-based cationic chalcogen bond donors in the catalytic activation of quinoline derivatives is presented. In the presence of selected catalysts, rate accelerations of up to 2300 compared to virtually inactive reference compounds are observed. The catalyst loading can be reduced to 1 molpercent while still achieving nearly full conversion for electron-poor and electron-rich quinolines. Contrary to expectations, preorganized catalysts were less active than the more flexible variants.
- Huber, S. M.,Steinke, T.,Wonner, P.
-
-
Read Online
- Selective hydrogenation of quinolines over a CoCu bimetallic catalyst at low temperature
-
Quinoline derivatives are widely exist in the environment, and mainly separated from the coal tar pitch fraction. Hydrogenation of these compounds to 1,2,3,4-tetrahydroquinolines, an important class of natural products and medicinal agents, is a significant transformation of waste to valuable chemicals. In the present work, we developed a cheap and highly efficient Co3Cu1Ox bimetallic catalyst and used it for the hydrogenation of quinolines at a temperature down to 60 °C. The introduction of Cu into Co catalyst changed the physical and chemical features of Co catalyst, which was characterized by Raman spectra, N2-adsorption/desorption isotherms, H2-TPR and H2-TPD tests. The recycling experiments indicated the catalyst was stable and possessed good reusability. Importantly, the gram-scale experiment provided a high yield (92%) to the target product, demonstrating that the catalytic system has a potential practical application.
- He, Zhen-Hong,Li, Na,Wang, Kuan,Wang, Wei-Tao,Liu, Zhao-Tie
-
-
Read Online
- Method for selective catalytic hydrogenation of aromatic heterocyclic compounds in non-hydrogen participation manner
-
The invention discloses a method for selective catalytic hydrogenation of aromatic heterocyclic compounds in a non-hydrogen participation manner. The method comprises the following steps: by taking 1, 5-cyclooctadiene iridium chloride dimer as a catalyst and phenylsilane as a hydrogen source, carrying out stirring reaction under mild conditions without adding a ligand, namely catalytically hydrogenating the aromatic heterocyclic compounds to obtain hydrogenated products of the aromatic heterocyclic compounds. The method has the advantages of low cost, mild reaction conditions, high selectivity and the like, and special equipment such as a high-pressure kettle and the like and high-temperature conditions which are required when hydrogen is used are avoided.
- -
-
Paragraph 0025-0029; 0065-0069
(2021/08/19)
-
- Heterogeneous Hydrogenation of Quinoline Derivatives Effected by a Granular Cobalt Catalyst
-
We communicate a convenient method for the pressure hydrogenation of quinolines in aqueous solution by using a particulate cobalt-based catalyst that is prepared in situ from simple Co(OAc)2 4H2O through reduction with abundant zinc powder. This catalytic protocol permits a brisk and atom-efficient access to a variety of 1,2,3,4-tetrahydroquinolines thereby relying solely on easy-to-handle reagents that are all readily obtained from commercial sources. Both the reaction setup assembly and the autoclave charging procedure are conducted on the bench outside an inert-gas-operated containment system, thus rendering the overall synthesis time-saving and operationally very simple.
- Timelthaler, Daniel,Topf, Christoph
-
p. 629 - 642
(2021/11/22)
-
- Catalytic Hydrogenation of Substituted Quinolines on Co–Graphene Composites
-
A set of 20 composites was prepared by pyrolysis of Co2+ complexes with 1,10-phenanthroline, melamine and 1,2-diaminobenzene. These composites were tested as the catalysts for the hydrogenation of quinolines. As shown by powder X-ray diffraction and TEM, the composited contained Co particles of several dozen nm sizes. The composition (elements content), Raman spectra X-ray photoelectron spectra parameters of the composites were analyzed. It was found that there was no distinct factor that controlled the yield of 1,2,3,4-tetrahydroquinolines in the investigated process. The yields of the respective products were in the range 90–100 %. The three most active composites were selected for scale-up and hydrogenation of a series of substituted quinolines. Up to 97 % yield of 1,2,3,4-tetrahydroquinoline was obtained on a 50 g scale. Five representative substituted quinolines were synthesized on a 10–20 grams scale using the Co-containing composites as the catalysts.
- Asaula, Vitalii M.,Buryanov, Volodymyr V.,Solod, Bohdan Y.,Tryus, Daryna M.,Pariiska, Olena O.,Kotenko, Igor E.,Volovenko, Yulian M.,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Kolotilov, Sergey V.
-
p. 6616 - 6625
(2021/12/24)
-
- Homogeneous pressure hydrogenation of quinolines effected by a bench-stable tungsten-based pre-catalyst
-
We report on an operationally simple catalytic method for the tungsten-catalyzed hydrogenation of quinolines through the use of the easily handled and self-contained precursor [WCl(η5-Cp)(CO)3]. This half sandwich complex is indefinitely storable on the bench in simple screw-capped bottles or stoppered flasks and can, if required, be prepared on a multi-gram scale while the actual catalytic transformations were performed in the presence of a Lewis acid in order to achieve both decent substrate conversions and product yields. The described method represents a facile and atom-efficient access to a variety of 1,2,3,4-tetrahydroquinolines that circumvents the use of cost-intensive and oxygen-sensitive phosphine ligands as well as auxiliary hydride reagents.
- Heizinger, Christian,Topf, Christoph,Vielhaber, Thomas
-
p. 451 - 461
(2021/11/11)
-
- 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)
-
- Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
-
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.
- Liu, Shuyang,Tian, Miao,Bu, Xiubin,Tian, Hua,Yang, Xiaobo
-
supporting information
p. 7738 - 7744
(2021/05/07)
-
- Encapsulating Cobalt into N-Doping Hollow Frameworks for Efficient Cascade Catalysis
-
The development of nonprecious catalysts for hydrogenation of organic molecules is of great importance in heterogeneous catalysis. Herein, we report a series of N-doped hollow carbon frameworks encompassing cobalt nanoparticles (denoted as Co@NHF-900) constructed as a new kind of reusable catalyst for this purpose by pyrolysis of ZIF-8@Co-dopamine under Ar atmospheres. Notably, the framework of ZIF-8 is essential for efficient catalyst by providing a carbon framework to support Co-dopamine. The experimental results reveal that the ZIF-8 renders a large hollow place within the catalysts, allowing the enrichment of the substrate and windows of the hollow structure and the ease of mass transfer of products during the reaction. All of the virtues made Co@NHF-900 a good candidate for hydrogenation of quinolines with high activity (TOF value of 119 h-1, which is several times than that of akin catalysts) and chemoselectivity.
- Yun, Ruirui,Zhang, Beibei,Qiu, Chuang,Ma, Ziwei,Zhan, Feiyang,Sheng, Tian,Zheng, Baishu
-
supporting information
p. 9757 - 9761
(2021/06/30)
-
- Cu-Catalyzed Chemoselective Reduction of N-Heteroaromatics with NH3·BH3 in Aqueous Solution
-
An efficient catalytic system was successfully developed on reduction of N-heteroaromatics with H3N?BH3 as hydrogen source in CuSO4 solution, featuring excellent chemoselectivity as well as very broad functional group tolerance. Various challenging substrates, such as OH-, NH2-, Cl-, Br-, etc., contained quinolines, quinoxalines, 1,5-naphthyridines and quinazolines were all reduced smoothly. Mechanistic studies suggested that [Cu-H] intermediate might be generated from NH3?BH3, which was believed to form with H3N?BH3 in CuSO4 solution.
- Gao, Chao,Xuan, Qingqing,Song, Qiuling
-
supporting information
p. 2504 - 2508
(2021/07/31)
-
- Cu Nanoclusters Anchored on the Metal-Organic Framework for the Hydrolysis of Ammonia Borane and the Reduction of Quinolines
-
Free-access active sites created and the interaction regulated between them and substrates during the heterogeneous catalysis process are crucial, which remain a great challenge. In this work, in suit reduced to afford naked Cu nanoparticles (NPs) have been anchored on the metal-organic framework (MOF), NH2-MOF, to form Cu-NH2-MOF. The strategy can precisely control the Cu NP formation with small size and uniform distribution. The Cu NP properties and MOF advantages have been integrated to create a great catalyst with multiple functions and have resulted in improving the recyclability and superb catalytic activity for the one-pot reduction of heterocycle reactions under mild conditions. The experimental and theoretical calculation results show that the superior performance should be attributed to the framework of NH2-MOF that provides large caves for substrate enrichment and the stabilization of Cu sites by the -NH2 group.
- Yun, Ruirui,Zhang, Beibei,Zhan, Feiyang,Du, Liting,Wang, Zhaoxu,Zheng, Baishu
-
supporting information
p. 12906 - 12911
(2021/08/30)
-
- Convenient synthesis of cobalt nanoparticles for the hydrogenation of quinolines in water
-
Easily accessible cobalt nanoparticles are prepared by hydrolysis of NaBH4 in the presence of inexpensive Co(ii) salts. The resulting material is an efficient catalyst for the hydrogenation of quinoline derivatives in water. The activity and chemoselectivity of this catalyst are comparable to other cobalt-based heterogeneous catalysts.
- Beller, Matthias,Dorcet, Vincent,Fischmeister, Cedric,Hervochon, Julien,Junge, Kathrin
-
p. 4820 - 4826
(2020/08/14)
-
- Boric acid catalyzed chemoselective reduction of quinolines
-
Boric acid promoted transfer hydrogenation of substituted quinolines to synthetically versatile 1,2,3,4-tetrahydroquinolines (1,2,3,4-THQs) was described under mild reaction conditions using a Hantzsch ester as a mild organic hydrogen source. This methodology is practical and efficient, where isolated yields are excellent and reducible functional groups are well tolerated in the N-heteroarene moiety. The reaction parameters and tentative mechanistic pathways are demonstrated by various control experiments and NMR studies. The present work can also be scaled up to obtain gram quantities and the utility of the developed process is illustrated by the transformation of 1,2,3,4-THQs into a series of biologically important molecules including the antiarrhythmic drug nicainoprol.
- Adhikari, Priyanka,Bhattacharyya, Dipanjan,Das, Animesh,Konwar, Monuranjan,Nandi, Sekhar,Sarmah, Bikash Kumar
-
supporting information
p. 1214 - 1220
(2020/02/22)
-
- A General Catalyst Based on Cobalt Core–Shell Nanoparticles for the Hydrogenation of N-Heteroarenes Including Pyridines
-
Herein, we report the synthesis of specific silica-supported Co/Co3O4 core–shell based nanoparticles prepared by template synthesis of cobalt-pyromellitic acid on silica and subsequent pyrolysis. The optimal catalyst material allows for general and selective hydrogenation of pyridines, quinolines, and other heteroarenes including acridine, phenanthroline, naphthyridine, quinoxaline, imidazo[1,2-a]pyridine, and indole under comparably mild reaction conditions. In addition, recycling of these Co nanoparticles and their ability for dehydrogenation catalysis are showcased.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Kreyenschulte, Carsten,Murugesan, Kathiravan
-
supporting information
p. 17408 - 17412
(2020/08/21)
-
- Fast and Efficient Nickel(II)-catalysed Transfer Hydrogenation of Quinolines with Ammonia Borane
-
Herein we report the first Ni(II)-catalysed transfer hydrogenation of quinolines using ammonia borane (AB) as hydrogen (H2) source. An in situ generated Ni(II)-bis(pyrazolyl)pyridine pre-catalyst could hydrogenate quinoline and its derivatives in excellent yields of up to 90% at 25 °C in 30 minutes. Spectroscopic studies revealed that a Ni(II)-hydride is responsible for the transfer hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline via a 1,4-dihydroquinoline intermediate. (Figure presented.).
- Vermaak, Vincent,Vosloo, Hermanus C. M.,Swarts, Andrew J.
-
supporting information
p. 5788 - 5793
(2020/12/01)
-
- Simple manganese carbonyl catalyzed hydrogenation of quinolines and imines
-
Manganese-catalyzed hydrogenation of unsaturated molecules has made tremendous progresses recently benefiting from non-innocent pincer or bidentate ligands for manganese. Herein, we describe the hydrogenation of quinolines and imines catalyzed by simple manganese carbonyls, Mn2(CO)10 or MnBr(CO)5, thus eliminating the prerequisite pincer-type or bidentate ligands.
- Wang, Zelong,Chen, Lei,Mao, Guoliang,Wang, Congyang
-
p. 1890 - 1894
(2020/03/04)
-
- Dual-Active-Sites Design of Co@C Catalysts for Ultrahigh Selective Hydrogenation of N-Heteroarenes
-
The dual-active-sites Co@C catalyst provides a general powerful strategy to break the limitation of scaling relation on traditional metal surfaces and thus affords unprecedentedly selective hydrogenation of various N-heteroarenes as well as high activity and stability. A porous carbon shell not only allows H2 diffusion to Co sites for activation but also blocks accessibility of N-heteroarenes, and the hydrogenation of N-heteroarenes is achieved on carbon by the spilled hydrogen from Co sites. In addition, the presence of surface/subsurface carbon at the Co sites shows high anti-sulfur poisoning and anti-oxidant capability. Ideal heterogeneous metal hydrogenation catalysts are featured by simultaneously high activity, selectivity, and stability. Herein, we report a general yet powerful strategy to design and fabricate dual-active-sites Co@C core-shell nanoparticle for boosting selective hydrogenation of various N-heteroarenes. It can break the limitation of scaling relation on traditional metal surfaces, and thus afford unprecedentedly high selectivity, activity, and stability. Combining kinetics analysis and DFT calculations with multiple techniques directly unveil that the critical porous carbon shell with a pore size of 0.53 nm not only allows H2 diffusion to Co sites for activation and blocks accessibility of N-heteroarenes but also catalyzes hydrogenation of N-heteroarenes via hydrogen spillover from Co sites. In addition, the presence of surface/subsurface carbon at the Co sites shows high anti-sulfur poisoning and anti-oxidant capability. This work is valuable for guiding the design and manipulation of cost-effective and robust hydrogenation catalysts. Our research can provide an environmentally friendly approach to afford unprecedentedly selective N-heteroarenes hydrogenation, which will greatly reduce the resource and energy consumption and decrease the amount of waste discharge and water pollution. Therefore, these results could help in achieving the “Clean water and sanitation” goal in the 10 UN Sustainable Development Goals. Meanwhile, the products of N-heteroarenes hydrogenation are the core structural motifs in both fine and bulk chemicals, which will make our life more beautiful. Thus, our research also benefits the “Good health and well-being” goal.
- Zhang, Sai,Gan, Jie,Xia, Zhaoming,Chen, Xiao,Zou, Yong,Duan, Xuezhi,Qu, Yongquan
-
supporting information
p. 2994 - 3006
(2020/09/04)
-
- Chemoselective hydrogenation of heteroarenes and arenes by Pd-Ru-PVP under mild conditions
-
Monometallic (Pd, Ru or Rh) and bimetallic (Pd0.5-Ru0.5) alloy NPs catalysts were examined for the hydrogenation of quinoline. Pd-Ru alloy catalyst showed superior catalytic activity to the traditional Rh catalyst. The characterization of Pd0.5-Ru0.5 catalysts, HAADF-EDX mapping and XPS analysis suggested that the alloy state of PdRu catalysts remained unchanged in the recovered catalyst. Furthermore, the catalyst was highly selective for the hydrogenation of different arenes. This journal is
- Abe, Naoya,Chaudhari, Chandan,Ikeda, Yasuyuki,Kitagawa, Hiroshi,Kusuda, Kohei,Matsumura, Syo,Nagaoka, Katsutoshi,Nishida, Yoshihide,Sato, Katsutoshi,Terada, Kenji,Toriyama, Takaaki,Yamamoto, Tomokazu
-
p. 44191 - 44195
(2020/12/25)
-
- Visible light-mediated Smiles rearrangements and annulations of non-activated aromatics
-
We report the first examples of radical cation Smiles rearrangements. A series of aryloxy alkylamines underwent spontaneous reaction, with the amino group displacing theipso-alkoxy group through substitution, at ambient temperature and under photoactivation by visible light in the presence of an acridinium catalyst (5 mol%). The study was extended to 3-(2-methoxyphenyl)propan-1-amine derivatives, which lack an appropriateipsoleaving group. Here, efficient cyclisations resulted in displacement of the methoxy group and formation of tetrahydroquinolines.
- Lawson, Connor A.,Dominey, Andrew P.,Williams, Glynn D.,Murphy, John A.
-
p. 11445 - 11448
(2020/10/12)
-
- Method for conducting catalytic hydrogenation on nitrogen-containing unsaturated heterocyclic compound
-
The invention provides a method for conducting catalytic hydrogenation on a nitrogen-containing unsaturated heterocyclic compound, and belongs to the technical field of catalytic hydrogenation. The provided method for conducting catalytic hydrogenation on the nitrogen-containing unsaturated heterocyclic compound comprises the following step: in the presence of hydrogen and a manganese catalyst, with the nitrogen-containing unsaturated heterocyclic compound as a substrate, carrying out a hydrogenation reaction. According to the method for conducting catalytic hydrogenation on the nitrogen-containing unsaturated heterocyclic compound, he adopted manganese catalyst is an NNP-type pincer manganese catalyst, has the advantages of being cheap, easy to obtain and low in toxicity compared with noble metal catalysts, has the advantages of being wide in substrate applicability and high in target product yield compared with an existing cheap metal iron catalyst or cobalt catalyst, and is higher in electron donating ability and smaller in steric hindrance compared with a PNP-type pincer manganese catalyst, and thus shows higher reaction activity in a series of hydrogenation reactions, and thetarget product yield is up to 99%.
- -
-
Paragraph 0094-0104
(2020/01/03)
-
- General and Chemoselective Copper Oxide Catalysts for Hydrogenation Reactions
-
Copper oxide catalysts have been prepared by pyrolysis of copper acetate on aluminum oxide. The material resulting from pyrolysis at 800 °C allows for catalytic hydrogenations at low temperature of a variety of unsaturated compounds such as quinolines, alkynes, ketones, imines, and polycyclic aromatic hydrocarbons as well as nitroarenes with good activity and selectivity.
- Li, Wu,Cui, Xinjiang,Junge, Kathrin,Surkus, Annette-Enrica,Kreyenschulte, Carsten,Bartling, Stephan,Beller, Matthias
-
p. 4302 - 4307
(2019/05/08)
-
- Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates
-
Anionic α-diimine cobalt complexes, such as [K(thf)1.5{(DippBIAN)Co(η4-cod)}] (1; Dipp=2,6-diisopropylphenyl, cod=1,5-cyclooctadiene), catalyze the dehydrogenation of several amine-boranes. Based on the excellent catalytic properties, an especially effective transfer hydrogenation protocol for challenging olefins, imines, and N-heteroarenes was developed. NH3BH3 was used as a dihydrogen surrogate, which transferred up to two equivalents of H2 per NH3BH3. Detailed spectroscopic and mechanistic studies are presented, which document the rate determination by acidic protons in the amine-borane.
- Maier, Thomas M.,Sandl, Sebastian,Shenderovich, Ilya G.,Jacobi von Wangelin, Axel,Weigand, Jan J.,Wolf, Robert
-
supporting information
p. 238 - 245
(2019/01/04)
-
- Homogeneous Hydrogenation with a Cobalt/Tetraphosphine Catalyst: A Superior Hydride Donor for Polar Double Bonds and N-Heteroarenes
-
The development of catalysts based on earth abundant metals in place of noble metals is becoming a central topic of catalysis. We herein report a cobalt/tetraphosphine complex-catalyzed homogeneous hydrogenation of polar unsaturated compounds using an air- and moisture-stable and scalable precatalyst. By activation with potassium hydroxide, this cobalt system shows both high efficiency (up to 24 000 TON and 12 000 h-1 TOF) and excellent chemoselectivities with various aldehydes, ketones, imines, and even N-heteroarenes. The preference for 1,2-reduction over 1,4-reduction makes this method an efficient way to prepare allylic alcohols and amines. Meanwhile, efficient hydrogenation of the challenging N-heteroarenes is also furnished with excellent functional group tolerance. Mechanistic studies and control experiments demonstrated that a CoIH complex functions as a strong hydride donor in the catalytic cycle. Each cobalt intermediate on the catalytic cycle was characterized, and a plausible outer-sphere mechanism was proposed. Noteworthy, external inorganic base plays multiple roles in this reaction and functions in almost every step of the catalytic cycle.
- Duan, Ya-Nan,Du, Xiaoyong,Cui, Zhikai,Zeng, Yiqun,Liu, Yufeng,Yang, Tilong,Wen, Jialin,Zhang, Xumu
-
supporting information
p. 20424 - 20433
(2019/12/27)
-
- Cobalt-Catalyzed Hydrogenations via Olefin Cobaltate and Hydride Intermediates
-
Redox noninnocent ligands are a promising tool to moderate electron transfer processes within base-metal catalysts. This report introduces bis(imino)acenaphthene (BIAN) cobaltate complexes as hydrogenation catalysts. Sterically hindered trisubstituted alkenes, imines, and quinolines underwent clean hydrogenation under mild conditions (2-10 bar, 20-80 °C) by use of the stable catalyst precursor [(DippBIAN)CoBr2] and the cocatalyst LiEt3BH. Mechanistic studies support a homogeneous catalysis pathway involving alkene and hydrido cobaltates as active catalyst species. Furthermore, considerable reaction acceleration by alkali cations and Lewis acids was observed. The dinuclear hydridocobaltate anion with bridging hydride ligands was isolated and fully characterized.
- Sandl, Sebastian,Maier, Thomas M.,Van Leest, Nicolaas P.,Kr?ncke, Susanne,Chakraborty, Uttam,Demeshko, Serhiy,Koszinowski, Konrad,De Bruin, Bas,Meyer, Franc,Bodensteiner, Michael,Herrmann, Carmen,Wolf, Robert,Von Jacobi Wangelin, Axel
-
p. 7596 - 7606
(2019/08/20)
-
- 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
-
-
- Formal Deoxygenative Hydrogenation of Lactams Using PNHP-Pincer Ruthenium Complexes under Nonacidic Conditions
-
A formal deoxygenative hydrogenation of amides to amines with RuCl2(NHC)(PNHP) (NHC = 1,3-dimethylimizadol-2-ylidene, PNHP = bis(2-diphenylphosphinoethyl)amine) is described. Various secondary amides, especially NH-lactams, are reduced with H2 (3.0-5.0 MPa) to amines at a temperature range of 120-150 °C with 1.0-2.0 mol % of PNHP-Ru catalysts in the presence of Cs2CO3. This process consists of (1) deaminative hydrogenation of secondary amides to generate primary amines and alcohols, (2) dehydrogenative coupling of the transient amines with alcohols to generate imines, and (3) hydrogenation of imines to give the formally deoxygenated secondary amine products.
- Ogata, Osamu,Nara, Hideki,Matsumura, Kazuhiko,Kayaki, Yoshihito
-
supporting information
p. 9954 - 9959
(2019/12/24)
-
- Cobalt-bridged secondary building units in a titanium metal-organic framework catalyze cascade reduction of N-heteroarenes
-
We report here a novel Ti3-BPDC metal-organic framework (MOF) constructed from biphenyl-4,4′-dicarboxylate (BPDC) linkers and Ti3(OH)2 secondary building units (SBUs) with permanent porosity and large 1D channels. Ti-OH groups from neighboring SBUs point toward each other with an O-O distance of 2 ?, and upon deprotonation, act as the first bidentate SBU-based ligands to support CoII-hydride species for effective cascade reduction of N-heteroarenes (such as pyridines and quinolines) via sequential dearomative hydroboration and hydrogenation, affording piperidine and 1,2,3,4-tetrahydroquinoline derivatives with excellent activity (turnover number ~ 1980) and chemoselectivity.
- Feng, Xuanyu,Song, Yang,Chen, Justin S.,Li, Zhe,Chen, Emily Y.,Kaufmann, Michael,Wang, Cheng,Lin, Wenbin
-
p. 2193 - 2198
(2019/02/20)
-
- DIRECT C-H AMINATION AND AZA-ANNULATION
-
In some aspects, the present disclosure provides methods of aminating an aromatic compound comprising reacting an aminating agent with an aromatic compound in the presence of a rhodium catalyst. In some embodiments, the methods may comprise aminating an aromatic compound which contains multiple different functional groups. The methods described herein may also be used to create bicyclic system comprising reacting an intramolecular aminating agent with an aromatic ring to obtain a second ring containing a nitrogen atom. In another aspect, the methods described herein may also be used to create a cyclic aliphatic cyclic/poly cyclic amine system comprising a reacting an intramolecular aminating agent by insertion into a C(sp3)-H bond.
- -
-
Paragraph 0132; 0209
(2019/06/07)
-
- Cu-catalyzed reduction of azaarenes and nitroaromatics with diboronic acid as reductant
-
A ligand-free copper-catalyzed reduction of azaarenes with diboronic acid as reductant in an aprotic solvent under mild conditions has been developed. Most interestingly, the nitroazaarenes could be reduced exclusively to give the corresponding amines without touching the azaarene moieties. Furthermore, the reductive amination of aromatic nitro compounds and aromatic aldehydes has also been realized. A series of hydrogenated azaarenes and secondary amines were obtained with good functional group tolerance.
- Pi, Danwei,Zhou, Haifeng,Zhou, Yanmei,Liu, Qixing,He, Renke,Shen, Guanshuo,Uozumi, Yasuhiro
-
p. 2121 - 2129
(2018/03/23)
-
- Nanolayered Cobalt-Molybdenum Sulfides as Highly Chemo- and Regioselective Catalysts for the Hydrogenation of Quinoline Derivatives
-
Herein, a general protocol for the preparation of a broad range of valuable N-heterocyclic products by hydrogenation of quinolines and related N-heteroarenes is described. Interestingly, the catalytic hydrogenation of the N-heteroarene ring is chemoselectively performed when other facile reducible functional groups, including alkenes, ketones, cyanides, carboxylic acids, esters, and amides, are present. The key to successful catalysis relies on the use of a nanolayered cobalt-molybdenum sulfide catalyst hydrothermally synthesized from earth-abundant metal precursors. This heterogeneous system displays a tunable composition of phases that allows for catalyst regeneration. Its catalytic activity depends on the composition of the mixed phase of cobalt sulfides, being higher with the presence of Co3S4, and could also be associated with the presence of transient Co-Mo-S structures that mainly vanish after the first catalytic run.
- Sorribes, Iván,Liu, Lichen,Doménech-Carbó, Antonio,Corma, Avelino
-
p. 4545 - 4557
(2018/05/22)
-
- Synthesis method of 1, 2, 3, 4-tetrahydroquinoline compound
-
Belonging to the technical field of organic chemical synthesis, the invention discloses a synthesis method of a 1, 2, 3, 4-tetrahydroquinoline compound. The method adopts elemental iodine as the catalyst, uses borane as the reductant, and subjects a quinoline compound to catalytic reduction reaction, thus obtaining the product. Compared with the existing synthesis methods, the method has the greatest characteristics of use of cheap I2 as the catalyst, no need for metal to participate in reaction, mild reaction conditions, rapidity and high efficiency, high catalytic efficiency, simple operation, good selectivity, high product conversion rate up to 80% or more, is of great popularization and application value, and is beneficial to industrial production.
- -
-
Paragraph 0031; 0032; 0033; 0034
(2018/11/27)
-
- Recyclable cobalt(0) nanoparticle catalysts for hydrogenations
-
The search for new hydrogenation catalysts that replace noble metals is largely driven by sustainability concerns and the distinct mechanistic features of 3d transition metals. Several combinations of cobalt precursors and specific ligands in the presence of reductants or under high-thermal conditions were reported to provide active hydrogenation catalysts. This study reports a new method of preparation of small, monodisperse Co(0) nanoparticles (3-4 nm) from the reduction of commercial CoCl2 in the absence of ligands or surfactants. High catalytic activity was observed in hydrogenations of alkenes, alkynes, imines, and heteroarenes (2-20 bar H2). The magnetic properties enabled catalyst separation and multiple recyclings.
- Büschelberger, Philipp,Reyes-Rodriguez, Efrain,Sch?ttle, Christian,Treptow, Jens,Feldmann, Claus,Jacobi Von Wangelin, Axel,Wolf, Robert
-
p. 2648 - 2653
(2018/05/30)
-
- TYROSINE KINASE INHIBITOR AND PHARMACEUTICAL COMPOSITION COMPRISING SAME
-
The present invention relates to a tyrosine kinase inhibitor and a pharmaceutical composition comprising same. The tyrosine kinase inhibitor of the present invention has the structures as shown in the following formula (I) or (II):
- -
-
Paragraph 0222; 0223
(2018/03/25)
-
- Aerobic oxidative dehydrogenation of N-heterocycles catalyzed by cobalt porphyrin
-
An efficient catalytic procedure has been developed for the aerobic oxidative dehydrogenation of N-heterocycles by cobalt porphyrin in the absence of any additives. The catalytic system could tolerate various 1,2,3,4-tetrahydroquinoline derivatives and some other N-heterocycles. The corresponding N-heteroaromatics could be obtained in 59–86% yields. The mechanism investigation suggested that the aerobic oxidative dehydrogenation might proceed with imine intermediate through radical paths.
- Zhou, Weiyou,Chen, Dongwei,Sun, Fu'an,Qian, Junfeng,He, Mingyang,Chen, Qun
-
supporting information
p. 949 - 953
(2018/02/09)
-
- Iridium-catalyzed dehydrogenative α-Functionalization of (Hetero)aryl-Fused cyclic secondary amines with indoles
-
Herein, by employing dehydrogenation as a substrate-activating strategy, a new iridium-catalyzed direct α-functionalization of (hetero)aryl-fused cyclic secondary amines with indoles has been demonstrated, which proceeds with merits that include high step- and atom-efficiency, readily available feedstocks, a simple catalyst system, good functional group tolerance, and operational simplicity.
- Chen, Xiuwen,Zhao, He,Chen, Chunlian,Jiang, Huanfeng,Zhang, Min
-
supporting information
p. 1171 - 1174
(2018/02/23)
-
- N-doped hierarchical porous carbon anchored tiny Pd NPs: A mild and efficient quinolines selective hydrogenation catalyst
-
Chemoselective hydrogenation of quinolines is often subjected to the problems of leaching and poisoning of catalytic active site as well as harsh reaction conditions. Developing a novel and high-performance heterogeneous catalyst is of paramount importance yet a huge challenge. Herein, we report a facile and efficient strategy for preparing the large surface area and highly N-doped hierarchical porous carbon anchored tiny Pd NPs catalyst, in which the low-cost chitosan, nitrogen-rich ionic liquids are served as composite precursors and KZ molten salt as friendly pore-forming agent. And a series of Pd@CIL-T (C refers to chitosan, IL refers to ionic liquid, T = 600–900 °C) catalysts are successfully fabricated via pyrolyzing aforesaid composites at different temperatures followed by anchoring the highly dispersed and small-sized Pd NPs on their surface. Among all the prepared catalysts, Pd@CIL-900 exhibits the optimal catalytic performance towards the selective hydrogenation of quinoline under extremely mild conditions (0.6 mol% Pd, 0.1 MPa H2 and 50 °C). The kinetic experiments further reveal that such hydrogenation is subject to a pseudo-first order reaction and the apparent activation energy is as low as 41.1 kJ/mol, demonstrating excellent hydrogenation reaction rate. Moreover, the catalytic activity and selectivity are well maintained even after being reused for fifth reaction cycles.
- Zhang, Fengwei,Ma, Chunlan,Chen, Shuai,Zhang, Jianfei,Li, Zhihong,Zhang, Xian-Ming
-
p. 145 - 153
(2018/04/27)
-
- Highly active and recyclable Pt nanocatalyst for hydrogenation of quinolines and isoquinolines
-
Thermoregulated phase-transfer Pt nanocatalyst was shown to be highly active, selective and recyclable in the hydrogenation of quinolines and isoquinolines. The catalyst could be easily separated from the product by simple phase separation and directly reused in the next cycle without evident loss in catalytic activity and selectivity, even after ten recycles. Importantly, for quinoline, the TON of 10,474 is the highest value ever reported among Pt catalysts. More remarkably, for isoquinoline, the TON of 5340 is far ahead of the highest record among transition metal catalysts.
- Xue, Xiuru,Zeng, Min,Wang, Yanhua
-
-
- Ligand-Enabled Enantioselective Csp3 –H Activation of Tetrahydroquinolines and Saturated Aza-Heterocycles by RhI
-
The first rhodium(I)-catalyzed enantioselective intermolecular C (Formula presented.) –H activation of various saturated aza-heterocycles including tetrahydroquinolines, piperidines, piperazines, azetidines, pyrrolidines, and azepanes is presented. The combination of a rhodium(I) precatalyst and a chiral monodentate phosphonite ligand is shown to be a powerful catalytic system to access a variety of important enantio-enriched heterocycles from simple starting materials. Notably, the C (Formula presented.) –H activation of tetrahydroquinolines is especially challenging due to the adjacent C (Formula presented.) ?H bond. This redox-neutral methodology provides a new synthetic route to α-N-arylated heterocycles with high chemoselectivity and enantioselectivity up to 97 % ee.
- Gre?ies, Steffen,Klauck, Felix J. R.,Kim, Ju Hyun,Daniliuc, Constantin G.,Glorius, Frank
-
supporting information
p. 9950 - 9954
(2018/08/01)
-
- Olefin-Stabilized Cobalt Nanoparticles for C=C, C=O, and C=N Hydrogenations
-
The development of cobalt catalysts that combine easy accessibility and high selectivity constitutes a promising approach to the replacement of noble-metal catalysts in hydrogenation reactions. This report introduces a user-friendly protocol that avoids complex ligands, hazardous reductants, special reaction conditions, and the formation of highly unstable pre-catalysts. Reduction of CoBr2 with LiEt3BH in the presence of alkenes led to the formation of hydrogenation catalysts that effected clean conversions of alkenes, carbonyls, imines, and heteroarenes at mild conditions (3 mol % cat., 2–10 bar H2, 20–80 °C). Poisoning studies and nanoparticle characterization by TEM, EDX, and DLS supported the notion of a heterotopic catalysis mechanism.
- Sandl, Sebastian,Schwarzhuber, Felix,P?llath, Simon,Zweck, Josef,Jacobi von Wangelin, Axel
-
supporting information
p. 3403 - 3407
(2018/02/13)
-
- STABILIZATION OF ACTIVE METAL CATALYSTS AT METAL-ORGANIC FRAMEWORK NODES FOR HIGHLY EFFICIENT ORGANIC TRANSFORMATIONS
-
Metal-organic framework (MOFs) compositions based on post?synthetic metalation of secondary building unit (SBU) terminal or bridging OH or OH2 groups with metal precursors or other post-synthetic manipulations are described. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations, including the regioselective boryiation and siiylation of benzyiic C—H bonds, the hydrogenation of aikenes, imines, carbonyls, nitroarenes, and heterocycles, hydroboration, hydrophosphination, and cyclization reactions. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
- -
-
Paragraph 0349
(2019/01/07)
-
- Pyrimidine heterocyclic compounds, preparation method and application thereof
-
The present invention relates to compounds of a formula (I) shown in the description, and pharmaceutically acceptable salts, prodrugs and solvates thereof, and the compounds are useful for treating cancer and inflammation in mammals. The invention also discloses a preparation method for the compounds of the formula (I) and a pharmaceutical composition containing the compound.
- -
-
-