3586-12-7Relevant academic research and scientific papers
Catalytic production of anilines by nitro-compounds hydrogenation over highly recyclable platinum nanoparticles supported on halloysite nanotubes
Aepuru, Radhamanohar,Bustamante, Tatiana M.,Campos, Cristian H.,Leal-Villarroel, Edgardo,Mangalaraja, Ramalinga Viswanathan,Shanmugaraj, Krishnamoorthy,Torres, Cecilia C.,Vinoth, Victor
, (2021/07/28)
Pt-nanoparticles supported on halloysite-nanotubes (HNTs) were selectively deposited onto the inner (Pt(IN)/HNT) or outer (Pt(OUT)/HNT) surface of the support to evaluate their operational stability on the cleaner and efficient hydrogenation of nitro compounds to produce their corresponding anilines. The formation of Pt0-aggregates on the inner or outer surfaces was observed, with mean particles sizes of 2.4–2.9 nm. The catalysts were evaluated using ethanol as solvent and nitrobenzene as a model substrate at a temperature of 298 K, under 1 bar of H2 pressure. The Pt(IN)/HNT catalyst showed better catalytic performance than Pt(OUT)/HNT, which was mainly attributed to the confinement effect of the Pt-nanoparticles inside the HNTs. However, the operational stability showed that Pt(OUT)/HNT retained its catalytic performance after 15 cycles, while the Pt(IN)/HNT catalyst suffered deactivation after the 5th cycle. The best catalytic system showed a moderate-to-high efficiency in the efficient hydrogenation of 7 nitro compounds used to produce their corresponding anilines, which are important pharmaceutical building blocks.
Noble metal nanoparticles supported on titanate nanotubes as catalysts for selective hydrogenation of nitroarenes
Aepuru, Radhamanohar,Bustamante, Tatiana M.,Campos, Cristian H.,Mangalaraja, Ramalinga Viswanathan,Shanmugaraj, Krishnamoorthy,Torres, Cecilia C.,de León, J. N. Díaz
, (2021/09/22)
Platinum (Pt) and palladium (Pd) nanoparticles (NPs) supported on titanate nanotubes (TiNTs) Pt@TiNT and Pd@TiNT were prepared for the liquid-phase hydrogenation of nitroarenes at 25 °C Initially, TiNT was modified with 3-aminopropyl-trimethoxysilane to provide a strong anchoring site to trap the Pt and Pd NPs, which prevent the metal NPs from leaching. As-prepared 1 wt% of metal loading catalysts were characterized by transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms, X-ray diffraction, and X-ray photoelectron spectroscopy measurements. The TEM images confirmed that the Pt (1.70 ± 0.19 nm) and Pd (2.80 ± 0.43 nm) NPs were mainly confined into the channel of TiNTs. Both catalysts exhibited excellent catalytic performances for the reduction of nitrobenzene as a model compound under mild reaction conditions. The superior catalytic activity for the hydrogenation of nitroarenes is attributed to the small size of the Pt and Pd NPs. However, the operational stability showed that Pt@TiNT retained its catalytic performance after 10 cycles, while Pd@TiNT suffered deactivation by metal sintering after the sixth cycle. The Pt@TiNT system exhibited high efficiency in the hydrogenation of different substituted nitroarenes of pharmaceuticals interest, and it showed an excellent activity and selectivity toward the production of desired substituted anilines.
Discovery of PqsE Thioesterase Inhibitors for Pseudomonas aeruginosa Using DNA-Encoded Small Molecule Library Screening
Bassler, Bonnie L.,Carson, Kenneth G.,Henke, Brad R.,Hone, Graham A. B.,Smith, Chari D.,Stergioula, Vasiliki,Taylor, Isabelle R.,Tota, Michael R.,Valastyan, Julie S.
, (2020/01/31)
Pseudomonas aeruginosa is a leading cause of hospital-acquired infections in the United States. PqsE, a thioesterase enzyme, is vital for virulence of P. aeruginosa, making PqsE an attractive target for inhibition. Neither the substrate nor the product of PqsE catalysis has been identified. A library of 550 million DNA-encoded drug-like small molecules was screened for those that bind to the purified PqsE protein. The structures of the bound molecules were identified by high throughput sequencing of the attached DNA barcodes. Putative PqsE binders with the strongest affinity features were examined for inhibition of PqsE thioesterase activity in vitro. The most potent inhibitors were resynthesized off DNA and examined for the ability to alter PqsE thermal melting and for PqsE thioesterase inhibition. Here, we report the synthesis, biological activity, mechanism of action, and early structure-activity relationships of a series of 2-(phenylcarbamoyl)benzoic acids that noncompetitively inhibit PqsE. A small set of analogs designed to probe initial structure-activity relationships showed increases in potency relative to the original hits, the best of which has an IC50 = 5 μM. Compound refinement is required to assess their in vivo activities as the current compounds do not accumulate in the P. aeruginosa cytosol. Our strategy validates DNA-encoded compound library screening as a rapid and effective method to identify catalytic inhibitors of the PqsE protein, and more generally, for discovering binders to bacterial proteins revealed by genetic screening to have crucial in vivo activities but whose biological functions have not been well-defined.
Cell-Based Optimization of Covalent Reversible Ketoamide Inhibitors Bridging the Unprimed to the Primed Site of the Proteasome β5 Subunit
Stubba, Daniel,Bensinger, Dennis,Steinbacher, Janika,Proskurjakov, Lilia,Salcedo Gómez, álvaro,Schmidt, Uwe,Roth, Stefan,Schmitz, Katja,Schmidt, Boris
supporting information, p. 2005 - 2022 (2019/11/22)
The ubiquitin-proteasome system (UPS) is an established therapeutic target for approved drugs to treat selected hematologic malignancies. While drug discovery targeting the UPS focuses on irreversibly binding epoxyketones and slowly-reversibly binding boronates, optimization of novel covalent-reversibly binding warheads remains largely unattended. We previously reported α-ketoamides to be a promising reversible lead motif, yet the cytotoxic activity required further optimization. This work focuses on the lead optimization of phenoxy-substituted α-ketoamides combining the structure-activity relationships from the primed and the non-primed site of the proteasome β5 subunit. Our optimization strategy is accompanied by molecular modeling, suggesting occupation of P1′ by a 3-phenoxy group to increase β5 inhibition and cytotoxic activity in leukemia cell lines. Key compounds were further profiled for time-dependent inhibition of cellular substrate conversion. Furthermore, the α-ketoamide lead structure 27 does not affect escape response behavior in Danio rerio embryos, in contrast to bortezomib, which suggests increased target specificity.
Oxalic amide ligands, and uses thereof in copper-catalyzed coupling reaction of aryl halides
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Page/Page column 101-102, (2020/01/09)
The present invention provides oxalic amide ligands and uses thereof in copper-catalyzed coupling reaction of aryl halides. Specifically, the present invention provides a use of a compound represented by formula I, wherein definitions of each group are described in the specification. The compound represented by formula I can be used as a ligand in copper-catalyzed coupling reaction of aryl halides for the formation of C—N, C—O and C—S bonds.
Structural optimization and structure–activity relationship of 4-thiazolidinone derivatives as novel inhibitors of human dihydroorotate dehydrogenase
Zeng, Fanxun,Quan, Lina,Yang, Guantian,Qi, Tiantian,Zhang, Letian,Li, Shiliang,Li, Honglin,Zhu, Lili,Xu, Xiaoyong
, (2019/08/07)
Human dihydroorotate dehydrogenase (hDHODH), one of the attractive targets for the development of immunosuppressive drugs, is also a potential target of anticancer drugs and anti-leukemic drugs. The development of promising hDHODH inhibitors is in high demand. Based on the unique binding mode of our previous reported 4-thiazolidinone derivatives, via molecular docking method, three new series 4-thiazolidinone derivatives were designed and synthesized as hDHODH inhibitors. The preliminary structure–activity relationship was investigated. Compound 9 of biphenyl series and compound 37 of amide series displayed IC50 values of 1.32 μM and 1.45 μM, respectively. This research will provide valuable reference for the research of new structures of hDHODH inhibitors.
Nickel-Catalyzed Cross-Coupling of Ammonia or Primary Alkylamines with (Hetero)aryl Sulfamates, Carbamates, or Pivalates
MacQueen, Preston M.,Stradiotto, Mark
supporting information, p. 1652 - 1656 (2017/08/11)
A catalyst system capable of effecting the cross-coupling of ammonia or primary alkylamines with (hetero)aryl sulfamates, carbamates, or pivalates is reported for the first time. The air-stable nickel(II) pre-catalyst C1 tolerates a broad spectrum of heterocyclic functionality within both reaction partners, as well as ether, nitrile, pyrrole, trifluoromethyl, and boronate ester substituents. In the case of reactions involving primary alkylamines and (hetero)aryl sulfamates and carbamates, room-temperature cross-couplings were achieved.
Carbon nitride supported palladium nanoparticles: An active system for the reduction of aromatic nitro-compounds
Nandi, Debkumar,Siwal, Samarjeet,Choudhary, Meenakshi,Mallick, Kaushik
, p. 31 - 38 (2016/06/09)
Synthesis of carbon nitride supported highly dispersed ultrafine palladium nanoparticles has been reported for the reduction of aromatic nitro-compounds using hydrazine hydrate as a reducing agent. As a demonstration, the as-synthesized carbon nitride-palladium composite was shown to be a highly active and chemo-selective for the title reaction. Utilizing the optimized reaction conditions a set of aromatic nitro compounds have been converted to their corresponding amine derivatives with good to excellent yield ranging from 80% to 99%. The catalyst can be used for multiple times without affecting the catalytic performance and can also be stored for a long time at ambient condition maintaining the high catalytic efficiency.
Betti base as an efficient ligand for copper-catalyzed ullmann coupling of phenol with aryl halides
Yang, Li,Yang, Qichao,Shi, Jianxin,Wang, Yufang,Zhang, Mingjie
supporting information, p. 2468 - 2477 (2014/08/05)
GRAPHICAL ABSTRACT A simple, general, and highly efficient Betti base ligand has been developed for copper-catalyzed Ullmann coupling of phenol with aryl halides without the protection of an inert atmosphere. The reaction proceeds smoothly in the presence of K2CO3 as the base and dimethylsulfoxide as the solvent. The catalyst was reused several times with no evident loss of catalytic activity and is environmentally friendly.
An Ullmann C-O coupling reaction catalyzed by magnetic copper ferrite nanoparticles
Yang, Shuliang,Wu, Cunqi,Zhou, Hua,Yang, Yanqin,Zhao, Yongxia,Wang, Chenxu,Yang, Wei,Xu, Jingwei
supporting information, p. 53 - 58 (2013/03/13)
Herein, an efficient method for the Ullmann C-O coupling reaction between various kinds of phenols and aryl halides, including amino, ketone, cyano, methyl, methoxy, fluoro, chloro and bromo derivatives, is described. The catalyst used, copper ferrite (CuFe2O4) nanoparticles, are easily made, air-stable, and of low cost. The catalyst can be recycled easily just by using an external magnet. Even in the presence of sensitive substituents, the reaction proceeds successfully to provide the desired products in high yields without protection of other functional groups. Copyright
