103796-41-4Relevant articles and documents
Uncoordinated Amine Groups of Metal-Organic Frameworks to Anchor Single Ru Sites as Chemoselective Catalysts toward the Hydrogenation of Quinoline
Wang, Xin,Chen, Wenxing,Zhang, Lei,Yao, Tao,Liu, Wei,Lin, Yue,Ju, Huanxin,Dong, Juncai,Zheng, Lirong,Yan, Wensheng,Zheng, Xusheng,Li, Zhijun,Wang, Xiaoqian,Yang, Jian,He, Dongsheng,Wang, Yu,Deng, Zhaoxiang,Wu, Yuen,Li, Yadong
, p. 9419 - 9422 (2017)
Here we report a precise control of isolated single ruthenium site supported on nitrogen-doped porous carbon (Ru SAs/N-C) through a coordination-assisted strategy. This synthesis is based on the utilization of strong coordination between Ru3+ and the free amine groups (-NH2) at the skeleton of a metal-organic framework, which plays a critical role to access the atomically isolated dispersion of Ru sites. Without the assistance of the amino groups, the Ru precursor is prone to aggregation during the pyrolysis process, resulting in the formation of Ru clusters. The atomic dispersion of Ru on N-doped carbon can be verified by the spherical aberration correction electron microscopy and X-ray absorption fine structure measurements. Most importantly, this single Ru sites with single-mind N coordination can serve as a semihomogeneous catalyst to catalyze effectively chemoselective hydrogenation of functionalized quinolones.
Fast and Efficient Nickel(II)-catalysed Transfer Hydrogenation of Quinolines with Ammonia Borane
Vermaak, Vincent,Vosloo, Hermanus C. M.,Swarts, Andrew J.
, p. 5788 - 5793 (2020)
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.).
Chemoselective reduction of heteroarenes with a reduced graphene oxide supported rhodium nanoparticle catalyst
Karakulina, Alena,Gopakumar, Aswin,Fei, Zhaofu,Dyson, Paul J.
, p. 5019 - 5097 (2018)
Rhodium nanoparticles immobilized on reduced graphene oxide were obtained from the microwave-induced thermal decomposition of Rh6(CO)16 in the ionic liquid [bmim][BF4] (bmim = 1-butyl-3-methylimidazolium cation) in the absence of additional stabilizing agents. The resulting rhodium nanoparticles are 99%, without interfering with other reducible groups, and with high conversions. Related catalysts prepared using conventional thermal heating were prepared for comparison purposes and were found to be considerably less active.
“Naked” Iridium(IV) Oxide Nanoparticles as Expedient and Robust Catalysts for Hydrogenation of Nitrogen Heterocycles: Remarkable Vicinal Substitution Effect and Recyclability
Ji, Yi-Gang,Wei, Kai,Liu, Teng,Wu, Lei,Zhang, Wei-Hua
, p. 933 - 940 (2017)
Iridium(IV) oxide nanoparticles were facilely prepared from iridium trichloride hydrate and sodium hydroxide by a ball-milling reaction at room temperature. The “naked” iridium nanocatalyst showed high stability and activity for the hydrogenation of a series of nitrogen heterocycles, for the first time, under a hydrogen balloon at room temperature with a selectivity of higher than 99%. Besides, an unprecedented substitution-dependent effect was discovered, where substrates with vicinal substituents on 2-, 3-, or 8-positions exhibited distinctly higher reaction rates than unsubstituted or remote substituted ones. Extraordinary recyclability was discovered in the hydrogenation of 2-methylquinoline for 30 runs without loss of activity. (Figure presented.).
Metal-Free Hydrogen Atom Transfer from Water: Expeditious Hydrogenation of N-Heterocycles Mediated by Diboronic Acid
Xia, Yun-Tao,Sun, Xiao-Tao,Zhang, Ling,Luo, Kai,Wu, Lei
, p. 17151 - 17155 (2016)
A hydrogenation of N-heterocycles mediated by diboronic acid with water as the hydrogen atom source is reported. A variety of N-heterocycles can be hydrogenated with medium to excellent yields within 10 min. Complete deuterium incorporation from stoichiometric D2O onto substrates further exemplifies the H/D atom sources. Mechanism studies reveal that the reduction proceeds with initial 1,2-addition, in which diboronic acid synergistically activates substrates and water via a six-membered ring transition state.
Continuous and Selective Hydrogenation of Heterocyclic Nitroaromatics in a Micropacked Bed Reactor
Chen, Xingkun,Duan, Xiaonan,Wang, Xuepeng,Zhang, Jisong
, p. 2100 - 2109 (2021)
The hydrogenation of heterocyclic nitroaromatics is of great importance in the pharmaceutical industry for the synthesis of key intermediates. However, high selectivity is difficult to achieve in conventional batch reactors owing to severe back mixing and poor mass transfer performance, resulting in the high requirement for subsequent separation processes. In this work, a continuous flow system based on a micropacked bed reactor is developed for the selective hydrogenation of heterocyclic nitroaromatics and the reductions of 5-nitroisoquinoline to 5-aminoisoquinoline and 5-amino-1,2,3,4-tetrahydroisoquinoline are selected as the model reactions. With the optimal reaction conditions, maximal yields of 99.9% (5-aminoisoquinoline) and 99.3% (5-amino-1,2,3,4-tetrahydroisoquinoline) are obtained successfully. Moreover, this system exhibits remarkable performance for the selective hydrogenation of relevant heterocyclic nitroaromatics with all yields beyond the level of 97.5%. The continuous flow system enables efficient hydrogenation of heterocyclic nitroaromatics and remarkable selectivity of target products with shorter reaction time and safer operation compared with batch reactors.
A Rhodium Nanoparticle-Lewis Acidic Ionic Liquid Catalyst for the Chemoselective Reduction of Heteroarenes
Karakulina, Alena,Gopakumar, Aswin,Ak?ok, Ismail,Roulier, Bastien L.,LaGrange, Thomas,Katsyuba, Sergey A.,Das, Shoubhik,Dyson, Paul J.
, p. 292 - 296 (2016)
We describe a catalytic system composed of rhodium nanoparticles immobilized in a Lewis acidic ionic liquid. The combined system catalyzes the hydrogenation of quinolines, pyridines, benzofurans, and furan to access the corresponding heterocycles, important molecules present in fine chemicals, agrochemicals, and pharmaceuticals. The catalyst is highly selective, acting only on the heteroaromatic ring, and not interfering with other reducible functional groups.
Efficient and selective hydrogenation of quinolines over FeNiCu/MCM-41 catalyst at low temperature: Synergism of Fe-Ni and Ni-Cu alloys
Cao, Zhe,He, Zhen-Hong,Liu, Zhao-Tie,Wang, Dan,Wang, Junlei,Wang, Kuan,Wang, Weitao,Yang, Yang,Zhang, Rong-Rong
, (2022/03/03)
The development of non-precious metal catalysts in heterogeneous catalytic processes is of great importance to the hydrogenation of quinolines for both theoretical and industrial applications. Herein, an effective non-precious metal catalyst, 58% Fe4Ni6Cu5/MCM-41, was developed to catalyze the hydrogenation of quinolines under the green and mild conditions, which can achieve 97.5% conversion and exceeding 98% selectivity to tetrahydroquinoline in solvent-free at low temperature of 50 °C. Moreover, the acceptable results of the reusability and gram scale-up experiments proved an industrial application potential of the as-prepared catalyst. Meanwhile, in cyclohexane system, 58% Fe4Ni6Cu5/MCM-41 catalyst can further realize a higher activity of the hydrogenation at a lower temperature of 40 °C, achieving 98.2% conversion and 98% selectivity to tetrahydroquinoline. The existence of Fe-Ni and Ni-Cu alloys in Fe4Ni6Cu5/MCM-41 catalyst was demonstrated by TEM, XRD, XPS, H2-TPD, and Raman spectroscopy. And, Fe-Ni and Ni-Cu alloys can be well dispersed onto MCM-41 molecular sieves. For Fe4Ni6Cu5/MCM-41 catalyst, quinoline molecules can be adsorbed by Fe3+ species on the surface of Fe-Ni alloy through the coordination, while hydrogen molecules can be adsorbed and activated by Ni-Cu alloy. Under the synergism of Fe-Ni and Ni-Cu alloys, the highly effective and selective hydrogenation of quinolines was achieved at low temperature and in solvent-free system. The present approach offers a prospective idea for building non-precious metal catalysts to realize the effective hydrogenation of N-heterocyclic compounds under mild conditions.
Heterogeneous Hydrogenation of Quinoline Derivatives Effected by a Granular Cobalt Catalyst
Timelthaler, Daniel,Topf, Christoph
, p. 629 - 642 (2021/11/22)
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.
