- Relative Study of Luminescent Properties with Judd-Ofelt Characterization in Trivalent Europium Complexes Comprising ethyl-(4-fluorobenzoyl) Acetate
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Five new europium(III) complexes Eu(p-EFBA)3.(H2O)2 (C1), Eu(p-EFBA)3.neo (C2), Eu(p-EFBA)3.batho (C3), Eu(p-EFBA)3.phen (C4), Eu(p-EFBA)3.bipy (C5) have been synthesized by using ethyl-(4-fluorobenzoyl) acetate (p-EFBA) as β-ketoester ligand and neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) as ancillary ligands. The synthesized complexes C1-C5 were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (1H-NMR), infrared (IR) spectroscopy, thermogravimetric analysis (TG/DTG), UV-visible and photoluminescence (PL) spectroscopy. The relative study of luminescence spectra of complexes with the previously reported complexes of isomeric ligand (ortho and meta substituted ligand) indicate the higher luminescence properties of complexes as an effect of fluorine position on β-ketoester ligand. The para substituted ligand shows a remarkable effect on quantum efficiencies and Judd-Ofelt intensity parameters (Ω2, Ω4) of the complexes. The higher value of intensity parameter Ω2 associated with hypersensitive 5D0?→?7F2 transition of europium(III) ion revealing highly polarizable ligand field. The purposed energy transfer mechanism of complexes indicates the efficient energy transfer in complexes.
- Devi, Rekha,Chahar, Sangeeta,Khatkar,Taxak,Boora, Priti
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Read Online
- Two Competitive but Switchable Organocatalytic Cascade Reaction Pathways: The Diversified Synthesis of Chiral Acetal-Containing Bridged Cyclic Compounds
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The organocatalytic enantioselective synthesis of methanobenzodioxepine derivatives bearing a 6,6,5-bridged ring system is presented. The m-CPBA-triggered in situ α-oxidation of β-oxoesters to provide the required but unstable α-hydroxy-β-dicarbonyl substrates is the key to this three-step sequence, providing the desired cyclic acetals with excellent stereoselectivities containing two bridgehead and one fully substituted stereocenters. It is noteworthy that the absence of m-CPBA furnished the acetal products bearing a 6,6,6-bridged ring system with similar good results from the same starting materials.
- Lv, Xue-Jiao,Chen, Ying-Han,Liu, Yan-Kai
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Read Online
- Electrochemical Oxidative Cyclization: Synthesis of Polysubstituted Pyrrole from Enamines
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A conceptually novel method for the preparation of pyrrole is described by electrochemical-oxidation-induced intermolecular annulation via enamines. In a simple undivided cell, based on a sodium acetate-facilitated, polysubstituted pyrrole derivations has been facilely synthesized under external oxidant-free condition. This electrosynthetic approach providing an environmentally benign protocol for C?C bond cross-coupling and oxidative annulation, which features unparalleled broad scope of substrates and practicality.
- Chen, Zhiwei,Shi, Guang,Tang, Wei,Sun, Jie,Wang, Wenxing
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supporting information
p. 951 - 955
(2021/02/03)
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- Construction of isoxazolone-fused phenanthridinesviaRh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones
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A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.
- Hu, Wangcheng,He, Xinwei,Zhou, Tongtong,Zuo, Youpeng,Zhang, Shiwen,Yang, Tingting,Shang, Yongjia
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supporting information
p. 552 - 556
(2021/02/06)
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- Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
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A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
- Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
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supporting information
p. 3173 - 3180
(2021/04/21)
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- Photoinduced Diverse Reactivity of Diazo Compounds with Nitrosoarenes
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A diverse reactivity of diazo compounds with nitrosoarene in an oxygen-transfer process and a formal [2 + 2] cycloaddition is reported. Nitosoarene has been exploited as a mild oxygen source to oxidize an in situ generated carbene intermediate under visible-light irradiation. UV-light-mediated in situ generated ketenes react with nitosoarenes to deliver oxazetidine derivatives. These operationally simple processes exemplify a transition-metal-free and catalyst-free protocol to give structurally diverse α-ketoesters or oxazetidines.
- Roy, Sourav,Kumar, Gourav,Chatterjee, Indranil
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supporting information
p. 6709 - 6713
(2021/09/08)
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- Iridium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of Racemic β’-Keto-β-Amino Esters via Dynamic Kinetic Resolution
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An iridium/f-diaphos catalytic system for the enantioselective hydrogenation of α-substituted β-ketoesters via dynamic kinetic resolution is reported. The desired anti β’-hydroxy-β-amino esters were obtained in moderate to good yields (60–95%) with 72–99% ees and 91:9 to 99:1 drs. This protocol tolerates various functional groups and could be easily conducted on gram scale with lower catalyst loading (TON up to 9100). (Figure presented.).
- He, Jiayin,Huang, An,Ling, Fei,Wang, Shiliang,Wang, Yifan,Wang, Ze,Zhao, Xianghua,Zhong, Weihui
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supporting information
p. 4714 - 4719
(2021/09/02)
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- Palladium catalysed hydrolysis-free arylation of aliphatic nitriles for the synthesis of 4-arylquinolin-2-one/pyrazolone derivatives
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Palladium catalysed addition of arylboronic acid to the readily available 2-cyano-(N-aryl)-acetamide or ethyl-2-cyanoacetate followed by subsequent reaction transform them into the biologically significant 4-arylquinolin-2-one or pyrazolone derivatives. The reaction conditions are robust enough to prevent the hydrolysis of ester/amide moiety during arylation. In addition, the unactivated nitrile moiety in the acetonitrile also converted to the corresponding acetophenone derivative.
- Krishna Reddy, Singarajanahalli Mundarinti,Prasanna Kumari, Subramaniyan,Selva Ganesan, Subramaniapillai
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- Amide/Ester Cross-Coupling via C-N/C-H Bond Cleavage: Synthesis of β-Ketoesters
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Activated primary, secondary, and tertiary amides were coupled with enolizable esters in the presence of LiHMDS to obtain good yields of β-ketoesters at room temperature. Notably, this protocol provides an efficient, mild, and high chemoselectivity method
- Chen, Jiajia,Joseph, Devaneyan,Xia, Yuanzhi,Lee, Sunwoo
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p. 5943 - 5953
(2021/04/02)
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- Interweaving Visible-Light and Iron Catalysis for Nitrene Formation and Transformation with Dioxazolones
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Herein, visible-light-driven iron-catalyzed nitrene transfer reactions with dioxazolones for intermolecular C(sp3)-N, N=S, and N=P bond formation are described. These reactions occur with exogenous-ligand-free process and feature satisfactory to excellent yields (up to 99 %), an ample substrate scope (109 examples) under mild reaction conditions. In contrast to intramolecular C?H amidations strategies, an intermolecular regioselective C?H amidation via visible-light-induced nitrene transfer reactions is devised. Mechanistic studies indicate that the reaction proceeds via a radical pathway. Computational studies show that the decarboxylation of dioxazolone depends on the conversion of ground sextet state dioxazolone-bounding iron species to quartet spin state via visible-light irradiation.
- Tang, Jing-Jing,Yu, Xiaoqiang,Wang, Yi,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 16426 - 16435
(2021/05/13)
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- A Hammett Study of Clostridium acetobutylicum Alcohol Dehydrogenase (CaADH): An Enzyme with Remarkable Substrate Promiscuity and Utility for Organic Synthesis
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Described is a physical organic study of the reduction of three sets of carbonyl compounds by the NADPH-dependent enzyme Clostridium acetobutylicum alcohol dehydrogenase (CaADH). Previous studies in our group have shown this enzyme to display broad substrate promiscuity, yet remarkable stereochemical fidelity, in the reduction of carbonyl compounds, including α-, β- and γ-keto esters (d -stereochemistry), as well as α,α-difluorinated-β-keto phosphonate esters (l -stereochemistry). To better mechanistically characterize this promising dehydrogenase enzyme, we report here the results of a Hammett linear free-energy relationship (LFER) study across three distinct classes of carbonyl substrates; namely aryl aldehydes, aryl β-keto esters and aryl trifluoromethyl ketones. Rates are measured by monitoring the decrease in NADPH fluorescence at 460 nm with time across a range of substrate concentrations for each member of each carbonyl compound class. The resulting v 0 versus [S] data are subjected to least-squares hyperbolic fitting to the Michaelis-Menton equation. Hammett plots of log(V max) versus σ X yield the following Hammett parameters: (i) for p -substituted aldehydes, ρ = 0.99 ± 0.10, ρ = 0.40 ± 0.09; two domains observed, (ii) for p -substituted β-keto esters ρ = 1.02 ± 0.31, and (iii) for p -substituted aryl trifluoromethyl ketones ρ = -0.97 ± 0.12. The positive sign of ρ indicated for the first two compound classes suggests that the hydride transfer from the nicotinamide cofactor is at least partially rate-limiting, whereas the negative sign of ρ for the aryl trifluoromethyl ketone class suggests that dehydration of the ketone hydrate may be rate-limiting for this compound class. Consistent with this notion, examination of the 13 C NMR spectra for the set of p -substituted aryl trifluo romethyl ketones in 2percent aqueous DMSO reveals significant formation of the hydrate (gem -diol) for this compound family, with compounds bearing the more electron-withdrawing groups showing greater degrees of hydration. This work also presents the first examples of the CaADH-mediated reduction of aryl trifluoromethyl ketones, and chiral HPLC analysis indicates that the parent compound α,α,α-trifluoroacetophenone is enzymatically reduced in 99percent ee and 95percent yield, providing the (S)-stereoisomer, suggesting yet another compound class for which this enzyme displays high enantioselectivity.
- Berkowitz, David B.,Kudalkar, Gaurav P.,Lee, Joshua D.,Tiwari, Virendra K.
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supporting information
p. 237 - 247
(2020/02/18)
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- Promising new inhibitors of tyrosyl-DNA phosphodiesterase I (Tdp 1) combining 4- arylcoumarin and monoterpenoid moieties as components of complex antitumor therapy
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Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is an important DNA repair enzyme in humans, and a current and promising inhibition target for the development of new chemosensitizing agents due to its ability to remove DNA damage caused by topoisomerase 1 (Top1) poisons such as topotecan and irinotecan. Herein, we report our work on the synthesis and characterization of new Tdp1 inhibitors that combine the arylcoumarin (neoflavonoid) and monoterpenoid moieties. Our results showed that they are potent Tdp1 inhibitors with IC50 values in the submicromolar range. In vivo experiments with mice revealed that compound 3ba (IC50 0.62 μM) induced a significant increase in the antitumor effect of topotecan on the Krebs-2 ascites tumor model. Our results further strengthen the argument that Tdp1 is a druggable target with the potential to be developed into a clinically-potent adjunct therapy in conjunction with Top1 poisons.
- Ayine-tora, Daniel M.,Chand, Raina,Chepanova, Arina A.,Ilina, Ekaterina S.,Kaledin, Vasily I.,Khomenko, Tatyana M.,Korchagina, Dina V.,Lavrik, Olga I.,Leung, Ivanhoe K. H.,Nikolin, Valeriy P.,Patel, Jinal,Popova, Nelly A.,Reynisson, Jóhannes,Salakhutdinov, Nariman F.,Volcho, Konstantin P.,Zakharenko, Alexandra L.,Zakharova, Olga D.
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- Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
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Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
- Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
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supporting information
p. 1222 - 1226
(2020/02/15)
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- An efficient route for the synthesis of N-(1H-benzo[d]imidazol-2-yl)benzamide derivatives promoted by CBr4 in one pot
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A metal-free one-pot method for the synthesis of N-(1H-benzo[d]imidazol-2-yl)benzamide derivatives was proposed mediated by CBr4. The reaction went through ring formation and opening processes with only two protons leaving and the thermodynamically favorable products were selectively formed in moderate to good yields.
- Li, Songhua,Li, Yunyi,Ma, Chen,Xie, Caixia
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- Design, Synthesis, and Biochemical Characterization of Non-Native Antagonists of the Pseudomonas aeruginosa Quorum Sensing Receptor LasR with Nanomolar IC50 Values
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Quorum sensing (QS), a bacterial cell-to-cell communication system mediated by small molecules and peptides, has received significant interest as a potential target to block infection. The common pathogen Pseudomonas aeruginosa uses QS to regulate many of its virulence phenotypes at high cell densities, and the LasR QS receptor plays a critical role in this process. Small molecule tools that inhibit LasR activity would serve to illuminate its role in P. aeruginosa virulence, but we currently lack highly potent and selective LasR antagonists, despite considerable research in this area. V-06-018, an abiotic small molecule discovered in a high-throughput screen, represents one of the most potent known LasR antagonists but has seen little study since its initial report. Herein, we report a systematic study of the structure-activity relationships (SARs) that govern LasR antagonism by V-06-018. We synthesized a focused library of V-06-018 derivatives and evaluated the library for bioactivity using a variety of cell-based LasR reporter systems. The SAR trends revealed by these experiments allowed us to design probes with 10-fold greater potency than that of V-06-018 and 100-fold greater potency than other commonly used N-acyl-l-homoserine lactone (AHL)-based LasR antagonists, along with high selectivities for LasR. Biochemical experiments to probe the mechanism of antagonism by V-06-018 and its analogues support these compounds interacting with the native ligand-binding site in LasR and, at least in part, stabilizing an inactive form of the protein. The compounds described herein are the most potent and efficacious antagonists of LasR known and represent robust probes both for characterizing the mechanisms of LuxR-type QS and for chemical biology research in general in the growing QS field.
- Blackwell, Helen E.,Manson, Daniel E.,Nyffeler, Kayleigh E.,O'Reilly, Matthew C.
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- Double Enzyme-Catalyzed One-Pot Synthesis of Enantiocomplementary Vicinal Fluoro Alcohols
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A double-enzyme-catalyzed strategy for the synthesis of enantiocomplementary vicinal fluoro alcohols through a one-pot, three-step process including lipase-catalyzed hydrolysis, spontaneous decarboxylative fluorination, and subsequent ketoreductase-catalyzed reduction was developed. With this approach, β-ketonic esters were converted to the corresponding vicinal fluoro alcohols with high isolated yields (up to 92percent) and stereoselectivities (up to 99percent). This new cascade process addresses some issues in comparison with traditional methods such as environmentally hazardous reaction conditions and low stereoselectivity outcome.
- Fan, Jiajie,Lin, Xianfu,Peng, Yongzhen,Wang, Anlin,Wu, Qi,Xu, Jian,Xu, Weihua,Yu, Huilei
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supporting information
(2020/07/24)
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- Desymmetrization of meso-dicarbonatecyclohexene with β-Hydrazino carboxylic esters via a Pd-catalyzed allylic substitution cascade
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The desymmetrization of meso-dicarbonatecyclohexene with β-hydrazino carboxylic esters has been achieved via a RuPHOX/Pd-catalyzed allylic substitution cascade for the construction of chiral hexahydrocinnoline derivatives with high performance. Mechanistic studies reveal that the reaction exploits a pathway different from that of our previous work and that the first nitrogen nucleophilic process is the rate-determining step. The protocol could be conducted on a gram scale without any loss of catalytic behavior, and the corresponding chiral hexahydrocinnolines can undergo diverse transformations.
- Xu, Kai,Zheng, Yan,Ye, Yong,Liu, Delong,Zhang, Wanbin
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supporting information
p. 8836 - 8841
(2020/11/30)
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- Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
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Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine-or H2O2-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
- Bai, Feifei,Fang, Jianguo,Song, Zi-Long,Zhang, Baoxin
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p. 2214 - 2231
(2020/03/06)
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- General [4 + 1] Cyclization Approach to Access 2,2-Disubstituted Tetrahydrofurans Enabled by Electrophilic Bifunctional Peroxides
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A general [4 + 1] cyclization reaction of carbonyl nucleophiles with 2-iodomethylallyl peroxides, which function as unique electrophilic oxygen synthons, for the synthesis of a broad range of 2,2-disubstituted tetrahydrofurans is achieved under operationally simple conditions. The unprecedented asymmetric version of such reaction is also realized via chiral auxiliary-assisted cyclization, thus providing a distinct approach to access chiral tetrahydrofurans with high diastereoselectivities. The new method can be applied to the synthesis of core structure of posaconazole drug.
- Gao, Min,Zhao, Yukun,Zhong, Chen,Liu, Shengshu,Liu, Pengkang,Yin, Qi,Hu, Lin
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supporting information
p. 5679 - 5684
(2019/08/01)
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- Catalytic Mechanism Study on the 1,2- and 1,4-Transfer Hydrogenation of Ketimines and β-Enamino Esters Catalyzed by Axially Chiral Biscarboline-Based Alcohols
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Axial N-O alcohols, which have two large carboline moieties connected to the axis were synthesized and used in catalytic enantioselective 1,2- and 1,4-transfer hydrogenations of total 26 ketimines and β-enamino esters. Excellent levels of enantioselectivity ranging from 91% to 99% were achieved by using catalyst (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide. Interestingly, a mixture of (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide and (aR)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide was also able to provide high enantioselectivities up to 95% that is the same as that using pure (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide. A plausible catalytic mechanism was suggested and total four kinds of transition states (TS) including almost 60 TS structures were investigated using density functional theory (DFT) with different basis sets such as 6-311G(2d,p). The predicted activation energy data are consistent with the experimental results. (Figure presented.).
- Dong, Mengxian,Wang, Jie,Wu, Shijie,Zhao, Yang,Ma, Yangyang,Xing, Yongfei,Cao, Fei,Li, Longfei,Li, Zhenqiu,Zhu, Huajie
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supporting information
p. 4602 - 4610
(2019/08/30)
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- Development of 2-arylbenzo[: H] quinolone analogs as selective CYP1B1 inhibitors
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The CYP1B1 enzyme is regarded as a potential target for cancer prevention and therapy. Based on the structure of α-naphthoflavone (ANF), diverse 2-arylbenzo[h]quinolone derivatives were designed, synthesized and evaluated as selective CYP1B1 inhibitors. Compared with ANF, although few of the title compounds possessed comparable or slightly higher CYP1B1 inhibitory activity, these compounds displayed a significantly increased selectivity toward CYP1B1 over CYP1A2. Among them compounds 5e, 5g and 5h potently inhibited the activity of CYP1B1 with IC50 values of 3.6, 3.9 and 4.1 nM respectively, paralleled by an excellent selectivity profile. On the basis of predicted clogP values, these target compounds may exhibit improved water-solubility compared to ANF. In particular, 5h showed a great superiority in the reversal of CYP1B1-mediated docetaxel resistance in vitro. The current study may serve as a good starting point for the further development of more potent as well as specific CYP1B1 inhibitors capable of reversing CYP1B1-mediated anticancer-drug resistance.
- Dong, Jinyun,Wang, Zengtao,Meng, Qingqing,Zhang, Qijing,Huang, Guang,Cui, Jiahua,Li, Shaoshun
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p. 15009 - 15020
(2018/04/30)
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- Discovery of novel potent HCV NS5B polymerase non-nucleoside inhibitors bearing a fused benzofuran scaffold
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This letter describes the discovery of a fused benzofuran scaffold viable for preparing a series of novel potent HCV NS5B polymerase non-nucleoside inhibitors. Designed on the basis of the functionalized benzofuran derivative nesbuvir (HCV-796), these com
- Zhong, Min,Peng, Eric,Huang, Ningwu,Huang, Qi,Huq, Anja,Lau, Meiyen,Colonno, Richard,Li, Leping
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supporting information
p. 963 - 968
(2018/02/09)
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- In situ generation of nitrile oxides from copper carbene and tert -butyl nitrite: Synthesis of fully substituted isoxazoles
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Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.
- Chen, Rongxiang,Ogunlana, Abosede Adejoke,Fang, Shangwen,Long, Wenhao,Sun, Hongmei,Bao, Xiaoguang,Wan, Xiaobing
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supporting information
p. 4683 - 4687
(2018/07/06)
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- Pyrazole alcohol compound, pharmaceutical composition thereof and application thereof to drugs
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The invention discloses a 1-(3,5,6-trimethyl pyrazine-2-yl)-5-pyrazole alcohol compound, a tautomer thereof, a pharmaceutical composition thereof and application thereof to drugs. The 1-(3,5,6-trimethyl pyrazine-2-yl)-5-pyrazole alcohol compound has double effects of resisting platelet aggregation and protecting nerve cells, and comprises a compound as shown in the formula (I), a tautomer (Ia) thereof, or a stereoisomer, a geometrical isomer, a hydrate or a solvate thereof, or a pharmaceutically acceptable salt or prodrug as shown in the description. The 1-(3,5,6-trimethyl pyrazine-2-yl)-5-pyrazole alcohol compound and the pharmaceutical composition thereof provided by the invention can be used for preparing drugs for prevention and/or treatment and/or auxiliary treatment of cerebral apoplexy, cardiovascular and cerebrovascular diseases, senile dementia and complications thereof caused by thrombosis and excessive free radicals.
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Paragraph 0128; 0137
(2018/10/19)
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- Substituted phenyl pyrazolone derivatives and preparation and application (by machine translation)
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The present invention provides a substituted phenyl pyrazolone derivatives, in particular to a 2 - phenyl - pyrazoline - 3 - ketone compound and its pharmaceutically acceptable salt, solvate. The substituted acetic acid ethyl ester with sodium hydroxide in aqueous solution in the [...] reflux reaction, then in the palladium-carbon and hydrogen under the action of the hydrogenolysis benzyl, phenyl [...] obtained, with the bromochlorodifluoromethane alkane reaction to obtain the chloro, finally with the secondary amine on the condensation to obtain the target compound. The invention substituted phenyl pyrazoline compounds in vitro exhibits excellent capability of eliminating the free radicals, and have more strongly inhibit H3 receptor activity, exhibits excellent penetration of the blood brain barrier capacity, has a unique dual active, therefore, its for cerebral apoplexy, Alzheimer's disease, Parkinson's disease, progressive neurodegenerative diseases such as frozen sickness treatment has a unique clinical effect. The compound of the invention for treating central system system related disease and inflammatory disease application of the medicament. The formula structure is as follows: (by machine translation)
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Paragraph 0034; 0039; 0040
(2019/01/08)
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- Molecular Oxygen-Mediated Minisci-Type Radical Alkylation of Heteroarenes with Boronic Acids
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The carbon-carbon bond formation via autoxidation of organoboronic acid using 1 atm of O2 is achieved in a simple, clean, and green fashion. The approach allows a technically facile and environmentally benign access to structurally diverse heteroaromatics with medicinally privileged scaffolds. The strategy also displays its practicality and sustainability in the resynthesis of marketed drugs Crestor and pyrimethamine.
- Zhang, Lizhi,Liu, Zhong-Quan
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supporting information
p. 6594 - 6597
(2017/12/26)
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- Rhodium-catalyzed asymmetric hydrogenation of tetrasubstituted β-acetoxy-α-enamido esters and efficient synthesis of droxidopa
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A rhodium-catalyzed asymmetric hydrogenation of challenging tetrasubstituted β-acetoxy-α-enamido esters was developed, giving chiral β-acetoxy-α-amido esters in high yields with excellent enantioselectivities (up to >99% ee). The products could be easily transformed to β-hydroxy-α-amino acid derivatives which are valuable chiral building blocks and a novel route for the synthesis of droxidopa was also developed.
- Guan, Yu-Qing,Gao, Min,Deng, Xu,Lv, Hui,Zhang, Xumu
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supporting information
p. 8136 - 8139
(2017/07/24)
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- Bromide-Mediated C-H Bond Functionalization: Intermolecular Annulation of Phenylethanone Derivatives with Alkynes for the Synthesis of 1-Naphthols
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Bromide-mediated intermolecular annulation of phenylethanone derivatives with alkynes has been developed, which allows for the regioselective formation of polysubstituted 1-naphthols. The usage of readily available bromine catalyst, broad substrate scope, and mild conditions make this protocol very practical. Mechanistic investigations reveal that the bromination of phenylethanone derivatives occurs to yield bromo-substituted intermediates, which react in situ with alkynes to furnish the desired 1-naphthols.
- Lu, Tao,Jiang, Ya-Ting,Ma, Feng-Ping,Tang, Zi-Jing,Kuang, Liu,Wang, Yu-Xuan,Wang, Bin
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supporting information
p. 6344 - 6347
(2017/12/08)
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- INHIBITORS OF HEPATITIS C VIRUS POLYMERASE
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The present invention provides, among other things, compounds represented by the general Formula I: (I) and pharmaceutically acceptable salts thereof, wherein L and A (and further substituents) are as defined in classes and subclasses herein and compositions (e.g., pharmaceutical compositions) comprising such compounds, which compounds are useful as inhibitors of hepatitis C virus polymerase, and thus are useful, for example, as medicaments for the treatment of HCV infection.
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Paragraph 219; 220
(2016/10/11)
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- 2-AMINO-BENZIMIDAZOLE DERIVATIVES AND THEIR USE AS 5-LIPOXYGENASE AND/OR PROSTAGLANDIN E SYNTHASE INHIBITORS
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The present invention relates to benzimidazole derivatives having the general formula I, wherein n is 0 or 1; X1 and X2 are independently, at each occurrence, CR5 or N; Y is C1-C6 alkylene, wherein alkylene is optionally substituted with one to two C1-C3 alkyl groups; R1 is selected from the group consisting of hydrogen, halogen, C1-C6 alkoxy, -NH2, -NHR6, -NR7R8 and -NH-(R9)n-R10, n being 0 or 1; R2 is selected from the group consisting of hydrogen, halogen, C1-C6 alkyl, -NH2, -NHR6, - NR7R8 and -NH-(R9)n-R10; R3 is selected from the group consisting of hydrogen, hydroxyl, OR11, -NR7R8, C1-C6 alkoxy, C1-C6 alkyl, C3-C10 cycloalkyl, C1-C3 haloalkyl, -C(O)NHR11, aryl, heteroaryl and heterocyclyl, wherein each of said cycloalkyl, aryl, heteroaryl and heterocyclyl is optionally and independently substituted with one to four Ra groups; and R4 is selected from the group consisting of -NH2, -N(R12)(V)pR13, - NH(V)p-OR14, -NHC(O)R15, and groups of formula la shown below, and their use in the treatment of diseases, in particular inflammatory diseases, cancer, stroke and/or Alzheimer's disease.
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Page/Page column 55
(2016/03/12)
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- Synthesis and biological evaluation of pyrazolylthiazole carboxylic acids as potent anti-inflammatory-antimicrobial agents
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Current Letter presents design, synthesis and biological evaluation of a novel series of pyrazolylthiazole carboxylates 1a-1p and corresponding acid derivatives 2a-2p. All 32 novel compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema method as well as for in vitro antimicrobial activity. All the tested compounds exhibited excellent AI activity profile. Three compounds 1p (R = Cl, R1 = Cl), 2c (R = H, R1 = F) and 2n (R = Cl, R1 = OCH3) were identified as potent anti-inflammatory agents exhibiting edema inhibition of 93.06-89.59which is comparable to the reference drug indomethacin (91.32%) after 3 h of carrageenan injection while most of the other compounds displayed inhibition ≥80%. In addition, pyrazolylthiazole carboxylic acids (2a-2p) also showed good antimicrobial profile. Compound 2h (R = OCH3, R1 = Cl) showed excellent antimicrobial activity (MIC 6.25 μg/mL) against both Gram positive bacteria comparable with the reference drug ciprofloxacin (MIC 6.25 μg/mL).
- Khloya, Poonam,Kumar, Satish,Kaushik, Pawan,Surain, Parveen,Kaushik, Dhirender,Sharma, Pawan K.
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p. 1177 - 1181
(2015/03/14)
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- Novel Substituted Imidazopyrimidines as Gpbar1 Receptor Modulators
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The present invention relates to novel substituted imidazo[1,2-a]pyrimidine compounds of formula (I), their pharmaceutically acceptable salts, and their isomers, stereoisomers, conformers, tautomers, polymorphs, hydrates and solvates. The present inventio
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Paragraph 0115; 0116; 0117
(2015/05/13)
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- A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones
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A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed. This tandem reaction involves a Conrad-Limpach-type reaction, including the thermal condensation of N-aminopyrroles with the carbonyl group of β-oxo esters followed by the cyclization of Schiff base intermediates. Compared to the traditional Conrad-Limpach quinoline synthesis, we herein successfully applied copper(II) as a catalyst in this transformation to furnish 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones for the first time. Most of the substrates bearing electron-donating (EDG) and electron-withdrawing (EWG) groups worked well with this procedure. The corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science. A copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed, and the corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science.
- Tan, Cun,Xiang, Haoyue,He, Qian,Yang, Chunhao
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supporting information
p. 3656 - 3660
(2015/06/16)
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- 1,5-Diketones Synthesis via Three-Component Cascade Reaction
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A mild and efficient cascade synthesis of 1,5-diketones from readily available N,N-dicyclohexylmethylamine, 1,3-dicarbonyl compounds, and trifluoromethyl β-diketones has been developed. This cascade reaction occurs via an oxidation/Mannich reaction/Cope elimination/Michael addition/retro-Claisen reaction sequence, and provides multiple C-C bond formations in one pot. In addition, exquisite chemoselectivity is achieved in the reaction between 1,3-dicarbonyl compounds and trifluoromethyl β-diketones.
- Xing, Li-Juan,Lu, Tao,Fu, Wei-Li,Lou, Mei-Mei,Chen, Bo,Wang, Zhi-Shen,Jin, Yang,Li, Dan,Wang, Bin
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supporting information
p. 3076 - 3080
(2015/11/03)
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- HETEROCYCLIC COMPOUND
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Provided is a heterocyclic compound having an RORγt inhibitory activity. A compound represented by the formula (I): wherein ring A is an optionally substituted cyclic group, Q is a bond, optionally substituted C1-10 alkylene, optionally substituted C2-10 alkenylene, or optionally substituted C2-10 alkynylene, R1 is a substituent, ring B is a thiazole ring, an isothiazole ring or a dihydrothiazole ring, each of which is optionally further substituted by a substituent in addition to R2, and R2 is an optionally substituted cyclyl-carbonyl-C1-6 alkyl group, an optionally substituted aminocarbonyl-C1-6 alkyl group, an optionally substituted cyclyl-C1-6 alkyl group, an optionally substituted cyclyl-C1-6 alkylamino-carbonyl group, an optionally substituted aminocarbonyl-C2-6 alkenyl group, an optionally substituted C1-6 alkylcarbonylamino-C1-6 alkyl group, an optionally substituted cyclyl-aminocarbonyl group, an optionally substituted cyclyl-carbonyl group or an optionally substituted non-aromatic heterocyclic group, or a salt thereof.
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Paragraph 0465
(2014/06/24)
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- Facile functionalization at the C2 position of a highly substituted benzofuran
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To expedite an SAR study of the C2 position of a highly substituted benzofuran ring system, we developed a method for the preparation of a key precursor, iodide 10. From iodide 10, a diverse set of compounds with different substituents at the C2 position were prepared efficiently.
- He, Shuwen,Li, Peng,Dai, Xing,McComas, Casey C.,Du, Chunyan,Wang, Ping,Lai, Zhong,Liu, Hong,Yin, Jingjun,Bulger, Paul G.,Dang, Qun,Xiao, Dong,Zorn, Nicolas,Peng, Xuanjia,Nargund, Ravi P.,Palani, Anandan
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supporting information
p. 2212 - 2216
(2014/04/17)
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- TETRACYCLIC HETEROCYCLE COMPOUNDS AND METHODS OF USE THEREOF FOR THE TREATMENT OF VIRAL DISEASES
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The present invention relates to compounds of formula (I) that are useful as hepatitis C virus (HCV) NS5B polymerase inhibitors, the synthesis of such compounds, and the use of such compounds for inhibiting HCV NS5B polymerase activity, for treating or preventing HCV infections and for inhibiting HCV viral replication and/or viral production in a cell-based system.
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Paragraph 0780
(2014/08/07)
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- One pot direct synthesis of β-ketoesters via carbonylation of aryl halides using cobalt carbonyl
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A direct method for the synthesis of β-ketoesters from aryl halides (iodide, bromide) has been described by using cobalt carbonyl as carbon monoxide source in microwave irradiation. Using this protocol, a wide variety of substituted aryl halides has been successfully converted to corresponding β-ketoesters.
- Baburajan, Poongavanam,Elango, Kuppanagounder P.
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supporting information
p. 3525 - 3528
(2014/06/10)
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- HETEROCYCLYLPYRI (MI) DINYLPYRAZOLE AS FUNGICIDALS
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Heterocyclylpyri(mi)dinylpyrazole of the formula (I) in which R1 to R5, X1, U, Q, W, Y, n, a, b have the meanings given in the description, and agrochemically active salts, to their use and to methods and compositions for
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Page/Page column 90
(2013/04/24)
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- Design and synthesis of 6,7-methylenedioxy-4-substituted phenylquinolin-2(1H)-one derivatives as novel anticancer agents that induce apoptosis with cell cycle arrest at G2/M phase
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Novel 6,7-methylenedioxy-4-substituted phenylquinolin-2(1H)-one derivatives 12a-n were designed and prepared through an intramolecular cyclization reaction and evaluated for in vitro anticancer activity. Among the synthesized compounds, 6,7-methylenedioxy-4-(2,4-dimethoxyphenyl)quinolin-2(1H)-one (12e) displayed potent cytotoxicity against several different tumor cell lines at a sub-micromolar level. Furthermore, results of fluorescence-activated cell sorting (FACS) analysis suggested that 12e induced cell cycle arrest in the G2/M phase accompanied by apoptosis in HL-60 and H460 cells. This action was confirmed by Hoechst staining and caspase-3 activation. Due to their easy synthesis and remarkable biological activities, 4-phenylquinolin-2(1H)-one analogs (4-PQs) are promising new anticancer leads based on the quinoline scaffold. Accordingly, compound 12e was identified as a new lead compound that merits further optimization and development as an anticancer candidate.
- Chen, Yi-Fong,Lin, Yi-Chien,Huang, Po-Kai,Chan, Hsu-Chin,Kuo, Sheng-Chu,Lee, Kuo-Hsiung,Huang, Li-Jiau
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p. 5064 - 5075
(2013/09/02)
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- NOVEL SUBSTITUTED IMIDAZOPYRIMIDINES AS GPBAR1 RECEPTOR MODULATORS
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The present invention relates to novel substituted imidazo[1,2-a]pyrimidine compounds of formula (I), their pharmaceutically acceptable salts, and their isomers, stereoisomers, conformers, tautomers, polymorphs, hydrates and solvates. The present inventio
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Page/Page column 38; 39
(2013/05/09)
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- TEMPO-catalyzed aerobic oxygenation and nitrogenation of olefins via C=C double-bond cleavage
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A novel TEMPO-catalyzed aerobic oxygenation and nitrogenation of hydrocarbons via C=C double-bond cleavage has been disclosed. The reaction employs molecular oxygen as the terminal oxidant and oxygen-atom source by metal-free catalysis under mild conditions. This method can be used for the preparation of industrially and pharmaceutically important N- and O-containing motifs, directly from simple and readily available hydrocarbons.
- Wang, Teng,Jiao, Ning
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p. 11692 - 11695
(2013/09/02)
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- Tert-BuOK-Catalyzed condensation of ethyl diazoacetate to aldehydes and palladium-catalyzed 1,2-hydrogen migration for the synthesis of β-ketoesters under solvent-free conditions
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A mild and convenient method for the condensation of ethyl diazoacetate (EDA) with aldehydes catalyzed by tert-BuOK under solvent-free conditions was developed. The corresponding α-diazo-β-hydroxy esters were further converted into β-ketoesters through palladium-catalyzed 1,2-hydrogen migration under neat conditions. The two-step transformation exemplifies a simple method for the efficient and green synthesis of β-ketoesters. The Royal Society of Chemistry 2013.
- Chen, Shufeng,Yuan, Fang,Zhao, Haiying,Li, Baoguo
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p. 12616 - 12620
(2013/08/23)
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- HEPATITIS C INHIBITORS AND USES THEREOF
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This disclosure relates to: (a) compounds and salts thereof that, inter alia, inhibit HCV; (b) intermediates useful for the preparation of such compounds and salts; (c) compositions comprising such compounds and salts; (d) methods for preparing such intermediates, compounds, salts, and compositions; (e) methods of use of such compounds, salts, and compositions; and (f) kits comprising such compounds, salts, and compositions.
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Page/Page column 119
(2012/07/13)
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- Enantioselective titanium(III)-catalyzed reductive cyclization of ketonitriles
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Reduction, please! The title reaction affords ?-hydroxyketones, a common structural motif in biologically active natural products, in good yields and high enantioselectivities at room temperature. The commercially available ansa-titanocene 1 was found to be an efficient catalyst for this process, which presumably proceeds by addition of a ketyl radical to a nitrile.
- Streuff, Jan,Feurer, Markus,Bichovski, Plamen,Frey, Georg,Gellrich, Urs
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supporting information; experimental part
p. 8661 - 8664
(2012/09/21)
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- Quinolinyl pyrimidines: Potent inhibitors of NDH-2 as a novel class of anti-TB agents
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NDH-2 is an essential respiratory enzyme in Mycobacterium tuberculosis (Mtb), which plays an important role in the physiology of Mtb. Herein, we present a target-based effort to identify a new structural class of inhibitors for NDH-2. High-throughput screening of the AstraZeneca corporate collection resulted in the identification of quinolinyl pyrimidines as the most promising class of NDH-2 inhibitors. Structure-activity relationship studies showed improved enzyme inhibition (IC50) against the NDH-2 target, which in turn translated into cellular activity against Mtb. Thus, the compounds in this class show a good correlation between enzyme inhibition and cellular potency. Furthermore, early ADME profiling of the best compounds showed promising results and highlighted the quinolinyl pyrimidine class as a potential lead for further development.
- Shirude, Pravin S.,Paul, Beena,Roy Choudhury, Nilanjana,Kedari, Chaitanya,Bandodkar, Balachandra,Ugarkar, Bheemarao G.
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p. 736 - 740
(2012/10/29)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds and compositions and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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Page/Page column 29
(2012/11/08)
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- OXAZOLE AND THIAZOLE DERIVATIVES AS ALX RECEPTOR AGONISTS
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The invention relates to oxazole and thiazole derivatives of formula (I), wherein A, E, X, R1 and R2 are as defined in the description, their preparation and their use as pharmaceutically active compounds.
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Page/Page column 22; 35
(2012/05/20)
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- COMPOUNDS
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The present invention features compounds of formula (I): and salts thereof, pharmaceutical compositions comprising said compounds, and uses of such compounds in treating or preventing viral infections, such as HCV infections, and diseases associated with such infections.
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Page/Page column 43
(2012/06/01)
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- Highly diastereoselective and enantioselective synthesis of α-hydroxy β-amino acid derivatives: Lewis base catalyzed hydrosilylation of α-acetoxy β-enamino esters
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By design: A series of α-acetoxy-β-enamino esters 1 were synthesized and then subjected to catalytic asymmetric hydrosilylation. In the presence of a chiral Lewis base catalyst, the reactions proceeded smoothly to provide a wide range of chiral α-acetoxy β-amino acid derivatives in high yields with good diastereoselectivities and enantioselectivities. Copyright
- Jiang, Yan,Chen, Xing,Zheng, Yongsheng,Xue, Zhouyang,Shu, Chang,Yuan, Weicheng,Zhang, Xiaomei
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supporting information; experimental part
p. 7304 - 7307
(2011/09/16)
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