- Efficient and recyclable bimetallic Co–Cu catalysts for selective hydrogenation of halogenated nitroarenes
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Silica supported N-doped carbon layers encapsulating Co–Cu nanoparticles (Co1Cux@CN/SiO2) were prepared by a one-step impregnation of Co(NO3)2·6H2O, Cu(NO3)2·3H2O, urea and glucose, following in situ carbothermal reduction. Effects of Cu contents on the catalytic performance of the Co1Cux@CN/SiO2 catalysts were investigated for selective hydrogenation of p-chloronitrobenzene to p-chloroaniline. The Co1Cu0.30@CN/SiO2 with Cu/Co molar ratio of 0.30:1 presented much higher activity and stability than the monometallic Co@CN/SiO2 catalyst. The addition of Cu into Co1Cux@CN/SiO2 catalysts had favorable effects on the formation of highly active Co–N sites and N-doped carbon layer. The role of the N-doped carbon layer was to protect the Co from oxidation by air, and the Co1Cu0.30@CN/SiO2 could be reused for at least 12 cycles without decrease in catalytic efficiency. Mechanistic and in situ infrared studies revealed that the interaction effect between the Co and Cu atoms made the surface of Co highly electron rich, which decreased adsorption of halogen groups and resulting in the enhanced selectivity during chemoselective hydrogenation of halogenated nitroarenes for a wide scope of substrates.
- Lu, Xionggang,Ren, Jiaan,Sheng, Yao,Wang, Xueguang,Wu, Baoqin,Zou, Xiujing
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- Optimization of Potent ATAD2 and CECR2 Bromodomain Inhibitors with an Atypical Binding Mode
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Most bromodomain inhibitors mimic the interactions of the natural acetylated lysine (KAc) histone substrate through key interactions with conserved asparagine and tyrosine residues within the binding pocket. Herein we report the optimization of a series of phenyl sulfonamides that exhibit a novel mode of binding to non-bromodomain and extra terminal domain (non-BET) bromodomains through displacement of a normally conserved network of four water molecules. Starting from an initial hit molecule, we report its divergent optimization toward the ATPase family AAA domain containing 2 (ATAD2) and cat eye syndrome chromosome region, candidate 2 (CECR2) domains. This work concludes with the identification of (R)-55 (GSK232), a highly selective, cellularly penetrant CECR2 inhibitor with excellent physicochemical properties.
- Lucas, Simon C. C.,Atkinson, Stephen J.,Bamborough, Paul,Barnett, Heather,Chung, Chun-Wa,Gordon, Laurie,Mitchell, Darren J.,Phillipou, Alexander,Prinjha, Rab K.,Sheppard, Robert J.,Tomkinson, Nicholas C. O.,Watson, Robert J.,Demont, Emmanuel H.
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p. 5212 - 5241
(2020/06/10)
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- In Situ Synthesized Silica-Supported Co@N-Doped Carbon as Highly Efficient and Reusable Catalysts for Selective Reduction of Halogenated Nitroaromatics
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Silica-supported Co@N-doped carbon (Co@CN/SiO2) catalysts were first prepared by a one-step impregnation with a mixed solution of cobalt nitrate, glucose and urea, followed by in situ carbonization and reduction. The Co@CN/SiO2 catalysts were investigated for the selective reduction of nitro aromatics to the corresponding anilines using hydrazine hydrate. The Co@CN/SiO2-500 carbonized at 500 °C exhibited the highest catalytic activity and excellent stability without any decay of activity after 6 cycles for the reduction of nitrobenzene. Both metallic Co atoms and Co?N species formed in the Co@CN/SiO2 catalysts were active, but the Co?N species were dominant active sites. The high activities of the Co@CN/SiO2 catalysts were attributed to the synergistic effect between the Co and N atoms, promoting heterolytic cleavage of hydrazine to form H+/H? pairs. Representative examples demonstrated that the Co@CN/SiO2-500 could completely transform various halogen-substituted nitro aromatics to the corresponding halogenated anilines with high TOFs and selectivity of '99.5 percent.
- Sheng, Yao,Wang, Xueguang,Yue, Shengnan,Cheng, Gonglin,Zou, Xiujing,Lu, Xionggang
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p. 4632 - 4641
(2020/07/30)
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- Catalyst-Controlled Regioselective Chlorination of Phenols and Anilines through a Lewis Basic Selenoether Catalyst
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We report a highly efficient ortho-selective electrophilic chlorination of phenols utilizing a Lewis basic selenoether catalyst. The selenoether catalyst resulted in comparable selectivities to our previously reported bis-thiourea ortho-selective catalyst, with a catalyst loading as low as 1%. The new catalytic system also allowed us to extend this chemistry to obtain excellent ortho-selectivities for unprotected anilines. The selectivities of this reaction are up to >20:1 ortho/para, while the innate selectivities for phenols and anilines are approximately 1:4 ortho/para. A series of preliminary studies revealed that the substrates require a hydrogen-bonding moiety for selectivity.
- Dinh, Andrew N.,Maddox, Sean M.,Vaidya, Sagar D.,Saputra, Mirza A.,Nalbandian, Christopher J.,Gustafson, Jeffrey L.
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p. 13895 - 13905
(2020/11/03)
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- Utilization of a Hydrogen Source from Renewable Lignocellulosic Biomass for Hydrogenation of Nitroarenes
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Exploring of hydrogen source from renewable biomass, such as glucose in alkaline solution, for hydrogenation reactions had been studied since 1860s. According to proposed pathway, only small part of hydrogen source in glucose was utilized. Herein, the utilization of a hydrogen source from renewable lignocellulosic biomass, one of the most abundant renewable sources in nature, for a hydrogenation reaction is described. The hydrogenation is demonstrated by reduction of nitroarenes to arylamines in up to 95 % yields. Mechanism studies suggest that the hydrogenation occurs via a hydrogen transformation pathway.
- Tan, Fang-Fang,Tang, Kai-Li,Zhang, Ping,Guo, Yan-Jun,Qu, Mengnan,Li, Yang
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p. 4189 - 4195
(2019/03/07)
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- Copper-Mediated monochlorination of anilines and nitrogen-containing heterocycles
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A simple and selective copper(II) chloride-mediated monochlorination of anilines and nitrogen-containing heterocycles has been developed. Stirring a mixture of aniline, copper(II) chloride, lithium chloride in EtOH under reflux condition produced 4-chloroaniline with high yield. Eighteen substrates including substituted anilines, N-substituted anilines, N,N-disubstituted anilines, 5-nitroindole and carbazole were all reactive and afforded desired products in moderate to excellent yields (52%–98%).
- Yang, Xue-Yan,Zhao, Hong-Yi,Mao, Shuai,Zhang, San-Qi
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supporting information
p. 2708 - 2714
(2018/10/15)
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- Metal-Free Reduction of Aromatic Nitro Compounds to Aromatic Amines with B2pin2 in Isopropanol
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A metal-free reduction of aromatic nitro compounds to the corresponding amines has been achieved by a combination of B2pin2 and KOtBu in isopropanol. A series of nitro compounds containing various reducible functional groups were chemoselectively reduced in good to excellent yields.
- Lu, Hongtao,Geng, Zhiyue,Li, Jingya,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie
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supporting information
p. 2774 - 2776
(2016/06/15)
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- Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enones as potent inhibitors of human lactate dehydrogenase
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Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enone using structure-based design strategies resulted in inhibitors with considerable improvement in biochemical potency against human lactate dehydrogenase A (LDHA). These potent inhi
- Labadie, Sharada,Dragovich, Peter S.,Chen, Jinhua,Fauber, Benjamin P.,Boggs, Jason,Corson, Laura B.,Ding, Charles Z.,Eigenbrot, Charles,Ge, Hongxiu,Ho, Qunh,Lai, Kwong Wah,Ma, Shuguang,Malek, Shiva,Peterson, David,Purkey, Hans E.,Robarge, Kirk,Salphati, Laurent,Sideris, Steven,Ultsch, Mark,Vanderporten, Erica,Wei, Binqing,Xu, Qing,Yen, Ivana,Yue, Qin,Zhang, Huihui,Zhang, Xuying,Zhou, Aihe
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supporting information
p. 75 - 82
(2015/02/19)
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- AMINO-PYRIDINE-CONTAINING SPLEEN TYROSINE KINASE (SYK) INHIBITORS
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The invention provides certain amino-pyridine-containing compounds of the Formula (I) (I) or pharmaceutically acceptable salts thereof, wherein R3, R4, R5, R6, and the subscript n are as defined herein. The invention also provides pharmaceutical compositions comprising such compounds, and methods of using the compounds for treating diseases or conditions mediated by Spleen Tyrosine Kinase (Syk) kinase.
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Paragraph 00183
(2014/05/24)
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- CHEMICAL COMPOUNDS
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This invention relates to novel compounds having the formul and to their pharmaceutical compositions and to their methods of use. These novel compounds provide a treatment for cancer.
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Page/Page column 37-38
(2008/06/13)
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- BICYCLIC PYRIMIDIN-4-(3H)-ONES AND ANALOGUES AND DERIVATIVES THEREOF WHICH MODULATE THE FUNCTION OF THE VANILLOID-1 RECEPTOR (VR1)
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Compounds of formula (I); which are useful as therapeutic compounds, particularly in the treatment of pain and other conditions ameliorated by the modulation of the function of the vanilloid-1 receptor (VR1).
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Page/Page column 52
(2010/02/12)
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- Substituted benzazoles and methods of their use as inhibitors of Raf kinase
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New substituted benz-azole compounds, compositions and methods of inhibition of Raf kinase activity in a human or animal subject are provided. The new compounds compositions may be used either alone or in combination with at least one additional agent for the treatment of a Raf kinase mediated disorder, such as cancer.
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Page 231; 368
(2008/06/13)
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- Process for the production of 5-hydroxyoxazolidinones
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PCT No. PCT/GB97/00130 Sec. 371 Date Jul. 28, 1998 Sec. 102(e) Date Jul. 28, 1998 PCT Filed Jan. 17, 1997 PCT Pub. No. WO97/28138 PCT Pub. Date Aug. 7, 1997A process for the production of hydroxy-substituted oxazolidinones, particularly 5-hydroxyoxazolidinones, which are useful as intermediates in the synthesis of herbicidally active compounds, comprising treating a hydroxythiazolidinone with an oxidizing agent.
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- Hydrolysis and Fe2+-induced Reduction of N-Aryl -O-pivaloylhydroxylamines: Aqueous Solution Chemistry of Model Carcinogens.
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The N-aryl-O-pivaloylhydroxylamines, 1a-d, which serve as models for the carcinogenic metabolites of aromatic amines, decompose in aqueous media by heterolysis of the N-O bond.Substituent effects on rates of reaction and products of the decomposition of 1a-c are entirely consistent with the intermediacy of a singlet nitrenium ion.The least reactive compound in the series N-(4-nitrophenyl)-O-pivaloylhydroxylamine (1d) yields 4-nitroaniline (2d) as its major decomposition product.This material may be formed through H radical abstraction by a triplet ion, but a nitrene reaction appears to be more likely.In the presence of Fe2+ 1a-d undergo rapid reduction to the corresponding anilines 2a-d.This reaction requires complexation of the ester with Fe2+ and proceeds with heterolysis of the N-O bond since nearly quantitative yields of pivalic acid are isolated.The radical cations 25a-d appear to be the most likely precursors to the reduction products.
- Novak, Michael,Lagerman, Robert K.
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p. 4762 - 4769
(2007/10/02)
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- Acid- and Base-Dependent Hydrolysis of N-(Sulfonatooxy)-3-bromoacetanilide: Involvement of N-(3-Bromophenyl)hydroxylamine-O-sulfonate
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N-(Sulfonatooxy)-3-bromoacetanilide (1e) undergoes hydrolysis at 80 deg C in the range pH 1.0-8.0 by acid- and base-dependent processes and by an uncatalyzed path.The uncatalyzed reaction exhibits the same characteristics as the uncatalyzed N-O bond-cleavage reactions of the more reactive N-(sulfonatooxy)acetanilides.The pH-dependent pathways involve the hydrolysis of 1e to form N-(3-bromophenyl)hydroxylamine-O-sulfonate (2).This material cannot be directly detected under the conditions of this study, but its existence can be inferred from product study and trapping data.Although 2 undergoes decomposition entirely by heterolytic N-O bond cleavage to yield nitrenium ion intermediate 14, a less reactive analogue of 2, N-(3-bromophenyl)-O-pivaloylhydroxylamine (4), apparently undergoes competitive homolytic and heterolytic N-O bond cleavage to yield both the arylamino radical 17 and the nitrenium ion 14.Both 2 and 4 serve as models for certain suspected carcinogenic metabolites of polycyclic aromatic amines and amides.
- Novak, Michael,Rovin, Lise H.,Pelecanou, Maria,Mulero, Julio J.,Lagerman, Robert K.
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p. 2002 - 2010
(2007/10/02)
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- Copper(I)-Induced Bromo-Hydrogen Exchange of 2,3-Dibromoanilines
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The copper(I)-induced bromine-hydrogen exchange reaction of 2,3-dibromoaniline and 5-substituted 2,3-dibromoanilines in the 2-position has been kinetically studied in water-acetic acid-hydrochloric acid medium at 90 deg C.The dehalogenation reaction is of second order, first order in both substrate and Cu+, and may be interpreted as a reductive substitution, composed of two one-electron steps.The 2,3-dibromophenol was only qualitatively investigated, but gave similar results.
- Liedholm, Brita
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p. 877 - 884
(2007/10/02)
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