5339-85-5Relevant academic research and scientific papers
Gold(I)-Thiolate Oligomers for Catalytic Hydrogenation of Nitroaromatics in Aqueous and Organic Medium
You, Jyun-Guo,Jin, Dun-Yuan,Tseng, Wei-Bin,Tseng, Wei-Lung,Lin, Po-Chiao
, p. 4558 - 4567 (2020/08/19)
Thiolated gold nanoclusters (AuNCs) have been introduced to efficiently and selectively catalyze the hydrogenation of nitroaromatics due to the strong interaction of their S?Au-S staple motifs with the nitro groups of nitroaromatics. However, without a gold core, gold(I)-thiolate oligomers (AuSOs) with S?Au-S staple motifs are rarely explored as catalysts for nitroaromatics. Here, we report a straightforward strategy for the synthesis of AuSOs through hydroxyl radical-induced leaching of glutathione-capped gold nanoparticles (GSH-AuNPs). Raman spectroscopy and matrix-assisted laser desorption/ionization-time of flight mass spectrometry demonstrated that hydroxyl radical-triggered etching of the GSH-AuNPs resulted in the production of AuSOs, including Au4(GSH)7 and Au7(GSH)9. The AuSOs were found to catalyze NaBH4-mediated hydrogenation of 4-nitrophenol to 4-aminophenol with a chemoselectivity of ～100 percent and a normalized rate constant (Knor) of 4.8×105 s? g?1. In addition to the high affinity of the S?Au?S staple motifs for 4-nitrophenol, the unusual catalytic activity of the AuSOs was attributable to the fact that they efficiently catalyzed the production of H2 from NaBH4 and the reaction of dissolved oxygen and NaBH4. The chemoselectivity and applicability of the AuSOs were further verified by performing the catalytic reaction of methyl 2-(2-nitrophenyl) acetate or methyl 4-nitrobenzoate with NaBH4.
Hydrogenation Properties of Nanostructured Tungsten Carbide Catalysts in a Continuous-Flow Reactor
Braun, Max,Esposito, Davide
, p. 393 - 397 (2017/02/15)
Tungsten monocarbide (WC) obtained through a urea glass route showed a high activity and chemoselectivity for the continuous-flow reduction of a variety of nitro compounds under milder conditions than those reported previously. The favorable effect of the nanostructure was shown by comparison with other commercially available WC materials. Moreover, WC functioned as an efficient support for Ni nanoparticles. This expanded its range of applicability and led to a bimetallic Ni@WC composite characterized by a high activity for the hydrogenation of cardanol, a phenolic lipid obtained from cashew nut shells.
Pd-Catalyzed Selective Synthesis of Cyclic Sulfonamides and Sulfinamides Using K2S2O5 as a Sulfur Dioxide Surrogate
Konishi, Hideyuki,Tanaka, Hiromichi,Manabe, Kei
supporting information, p. 1578 - 1581 (2017/04/13)
A variety of cyclic sulfonamides and sulfinamides could be selectively synthesized under Pd catalysis using haloarenes bearing amino groups and a sulfur dioxide (SO2) surrogate. The amount of base was key in determining the selectivity. Mechanistic studies revealed that sulfinamides were initially formed via an unprecedented formal insertion of sulfur monoxide and were oxidized to sulfonamides in the presence of an iodide ion and DMSO.
Alloying Gold with Copper Makes for a Highly Selective Visible-Light Photocatalyst for the Reduction of Nitroaromatics to Anilines
Xiao, Qi,Sarina, Sarina,Waclawik, Eric R.,Jia, Jianfeng,Chang, Jin,Riches, James D.,Wu, Haishun,Zheng, Zhanfeng,Zhu, Huaiyong
, p. 1744 - 1753 (2016/03/15)
Finely control of product selectivity is an essential issue in organic chemical production. In the synthesis of functionalized anilines via reduction of the corresponding nitroarenes, the challenge is to selectively reduce only the nitro group in the presence of other reducible functional groups in nitroarene molecules at a high reaction rate. Normally, the nitroarene is reduced stepwise through a series of intermediates that remain as byproducts, increasing the aniline synthesis cost. Here we report that alloying small amounts of copper into gold nanoparticles can alter the reaction pathway of the catalytic reduction under visible-light irradiation at ambient temperature, allowing nitroaromatics to be transformed directly to anilines in a highly selective manner. The reasons for the high efficiency of the photocatalytic reduction under these comparatively benign conditions as well as the light-excited reaction mechanisms are discussed. This photocatalytic process avoids byproducts, exhibits a high reaction rate and excellent substituent tolerance, and can be used for the synthesis of many useful functionalized anilines under environmentally benign conditions. Switching of the reaction pathway simply by tailoring the bimetallic alloy NPs of the photocatalysts is effective for engineering of product chemoselectivity.
Towards a general ruthenium-catalyzed hydrogenation of secondary and tertiary amides to amines
Cabrero-Antonino, Jose R.,Alberico, Elisabetta,Junge, Kathrin,Junge, Henrik,Beller, Matthias
, p. 3432 - 3442 (2016/05/19)
A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1-tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the desired amines. The excellent isolated yields of two scale-up experiments corroborate the feasibility of the reaction protocol. Control experiments indicate that, after the initial reduction of the amide carbonyl group, the reaction proceeds through the reductive amination of the alcohol with the amine arising from collapse of the intermediate hemiaminal.
Asymmetric Intramolecular Conjugate Addition Nitro-Mannich Route to cis-2-Aryl-3-nitrotetrahydroquinolines
Anderson, James C.,Barham, Joshua P.,Rundell, Christopher D.
, p. 4090 - 4093 (2015/09/01)
Reductive cyclization of 2-iminonitrostyrenes (from the condensation of 2-aminostyrenes with an aldehyde and subsequent nitration of the alkene) using a bifunctional thiourea catalyst and tert-butyl-Hantzsch ester leads to an intramolecular conjugate hydride addition nitro-Mannich reaction to give the corresponding cis-2-aryl-3-nitrotetrahydroquinolines as single diastereoisomers in high yields and enantioselectivities.
Palladium-catalyzed direct coupling of 2-vinylanilines and isocyanides: An efficient synthesis of 2-aminoquinolines
Wang, Lijie,Ferguson, Jamie,Zeng, Fanlong
supporting information, p. 11486 - 11491 (2015/12/04)
Palladium-catalyzed oxidative coupling of 2-vinylanilines and isocyanides constitutes a direct, facile, and efficient approach to 2-aminoquinolines. The procedure, employing palladium acetate and silver carbonate, is attractive in terms of assembly efficiency, functional group tolerance, and operational simplicity. A variety of 2-aminoquinolines were prepared in good to excellent yields.
Pyrrolidinyl phenylurea derivatives as novel CCR3 antagonists
Nitta, Aiko,Iura, Yosuke,Inoue, Hideki,Imaoka, Takayuki,Takahashi, Toshiya,Sato, Ippei,Morihira, Koichiro,Kubota, Hirokazu,Morokata, Tatsuaki,Takeuchi, Makoto,Ohta, Mitsuaki,Tsukamoto, Shin-Ichi
, p. 6876 - 6881,6 (2020/09/02)
Optimization starting with our lead compound 1 (IC50 = 4.9 nM) led to the identification of pyrrolidinyl phenylurea derivatives. Further modification toward improvement of the bioavailability provided (R)-1-(1-((6-fluoronaphthalen-2-yl)methyl)pyrrolidin-3-yl)-3-(2-(2- hydroxyethoxy)phenyl)urea 32 (IC50 = 1.7 nM), a potent and orally active CCR3 antagonist.
Convenient and scalable process for the preparation of indole via raney nickel-catalyzed hydrogenation and ring closure
Guo, Xianghai,Peng, Zhiliang,Jiang, Shende,Shen, Jiaxiang
experimental part, p. 2044 - 2052 (2011/08/03)
An efficient and practical method for the synthesis of indole as a key starting material for many useful chemicals is described. Using 2-nitrotoluene as starting material, hydroxymethylation with formaldehyde under alkaline conditions gave 2-(2-nitrophenyl) ethanol on a large scale. Raney Ni catalyst was used for both reduction of the nitro group as well as for the indole formation. The overall yield was 78% from 2-nitrotoluene. Copyright
A new synthetic method of 1,4-dihydro-2h-3,1-benzoxazin-2-ones: Selenium-catalyzed reductive carbonylation of aromatic nitro compounds with carbon monoxide
Nishiyama, Yutaka,Naitoh, Yoshitaka,Sonoda, Noboru
, p. 886 - 888 (2007/10/03)
It was confirmed that selenium catalyzed the reaction of 2-nitrobenzyl alcohols with carbon monoxide to afford 1,4-dihydro-2H-3,1-benzoxazin-2-ones in good yields. Similarly, seven-membered cyclic carbamate was prepared by the reaction of 2-(2-nitrophenyl)ethanol with carbon monoxide.
