- Design, synthesis, modelling studies and biological evaluation of 1,3,4-oxadiazole derivatives as potent anticancer agents targeting thymidine phosphorylase enzyme
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A series of novel 1,3,4-oxadiazole derivatives with substituted phenyl ring were designed and synthesized with an objective of discovering newer anti-cancer agents targeting thymidine phosphorylase enzyme (TP). The 1,3,4-oxadiazole derivatives were synthesized by simple and convenient methods in the lab. Chemical structure of the all the synthesized compounds were characterized by IR, 1H NMR and mass spectral methods and evaluated for cytotoxicity by MTT method against two breast cancer cell lines (MCF-7 and MDA-MB-231). Further, results of TP assay identified that 1,3,4-oxadiazole molecules displayed anti-cancer activity partially by inhibition of phosphorylation of thymidine. The TP assay identified SB8 and SB9 as potential inhibitors with anti-cancer activity against both the cell lines. The molecular docking studies recognized the orientation and binding interaction of molecule at the active site amino acid residues of TP (PDB: 1UOU). Acute toxicity studies of compound SB8 at the dose of 5000 mg/kg has identified no signs of clinical toxicity was observed. The SARs study of synthesized derivatives revealed that the substitution of phenyl ring with electron withdrawing group at ortho position showed significant TP inhibitory activity compared to para substitution. The experimental data suggests that 1,3,4-oxadiazole with substituted phenyl can be taken as a lead for the design of efficient TP inhibitors and active compounds which can be taken up for further studies.
- Bajaj, Shalini,Kumar, Maushmi S.,Tinwala, Hussain,YC, Mayur
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- Oxidative esterification of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst
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The direct esterification of alcohols with non-noble metal-based catalytic systems faces great challenges. Here, we report a new chrome-based catalyst stabilized by a single pentaerythritol decorated Anderson-type polyoxometalate, [N(C4H9)4]3[CrMo6O18(OH)3C{(OCH2)3CH2OH}], which can realize the efficient transformation from alcohols to esters by H2O2oxidation in good yields and high selectivity without extra organic ligands. A variety of alcohols with different functionalities including some natural products and pharmaceutical intermediates are tolerated in this system. The chrome-based catalyst can be recycled several times and still keep the original configuration and catalytic activity. We also propose a reasonable catalytic mechanism and prove the potential for industrial applications.
- Wang, Jingjing,Jiang, Feng,Tao, Chaofu,Yu, Han,Ruhlmann, Laurent,Wei, Yongge
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supporting information
p. 2652 - 2657
(2021/04/21)
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- GPR52 Antagonist Reduces Huntingtin Levels and Ameliorates Huntington's Disease-Related Phenotypes
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GPR52 is an orphan G protein-coupled receptor (GPCR) that has been recently implicated as a potential drug target of Huntington's disease (HD), an incurable monogenic neurodegenerative disorder. In this research, we found that striatal knockdown of GPR52 reduces mHTT levels in adult HdhQ140 mice, validating GPR52 as an HD target. In addition, we discovered a highly potent and specific GPR52 antagonist Comp-43 with an IC50 value of 0.63 μM by a structure-activity relationship (SAR) study. Further studies showed that Comp-43 reduces mHTT levels by targeting GPR52 and promotes survival of mouse primary striatal neurons. Moreover, in vivo study showed that Comp-43 not only reduces mHTT levels but also rescues HD-related phenotypes in HdhQ140 mice. Taken together, our study confirms that inhibition of GPR52 is a promising strategy for HD therapy, and the GPR52 antagonist Comp-43 might serve as a lead compound for further investigation.
- Wang, Congcong,Zhang, Yu-Fang,Guo, Shimeng,Zhao, Quan,Zeng, Yanping,Xie, Zhicheng,Xie, Xin,Lu, Boxun,Hu, Youhong
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p. 941 - 957
(2020/11/30)
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- Development of phenyltriazole thiol-based derivatives as highly potent inhibitors of DCN1-UBC12 interaction
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Defective in cullin neddylation 1(DCN1) is a co-E3 ligase that is important for cullin neddylation. Dysregulation of DCN1 highly correlates with the development of various cancers. Herein, from the initial high-throughput screening, a novel hit compound 5a containing a phenyltriazole thiol core (IC50 value of 0.95 μM for DCN1-UBC12 interaction) was discovered. Further structure-based optimization leads to the development of SK-464 (IC50 value of 26 nM). We found that SK-464 not only directly bound to DCN1 in vitro, but also engaged cellular DCN1, suppressed the neddylation of cullin3, and hindered the migration and invasion of two DCN1-overexpressed squamous carcinoma cell lines (KYSE70 and H2170). These findings indicate that SK-464 may be a novel lead compound targeting DCN1-UBC12 interaction.
- Zhou, Wenjuan,Xu, Chenhao,Dong, Guanjun,Qiao, Hui,Yang, Jing,Liu, Hongmin,Ding, Lina,Sun, Kai,Zhao, Wen
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- Cobalt Nanoparticles-Catalyzed Widely Applicable Successive C?C Bond Cleavage in Alcohols to Access Esters
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Selective cleavage and functionalization of C?C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C?C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C?C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long-chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent ?(C?C)n? bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C?C bonds to achieve excellent catalytic activity, while the presence of Co-Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process.
- Dai, Wen,Gao, Shuang,Li, Guosong,Luo, Huihui,Lv, Ying,Shang, Sensen,Wang, Lianyue
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supporting information
p. 19268 - 19274
(2020/08/26)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- Facile synthesis of a highly efficient Co/Cu@NC catalyst for base-free oxidation of alcohols to esters
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The direct oxidation of alcohols to esters is an environmentally benign and cost-effective organic synthetic strategy, but it is still a great challenge to discover an economic, highly active, and long-term stable catalyst for efficient transformation of alcohols to esters under milder conditions. Herein, we developed cobalt and copper nanoparticle -co-decorated nitrogen-doped carbon catalysts (CoCu@NCn) through two steps of ball milling and calcination. It was found that CoCu@NCn could catalyze the oxidation of alcohols to esters effectively in the absence of basic additives. The catalytic activity was much higher than those of monometallic Co@NC2 and Cu@NC2 samples, and the catalyst can be conveniently recovered and quite steadily reused. Through a series of control experiments and characterizations, it is concluded that the remarkable catalytic performance of CoCu@NC2 was associated with the synergistic effect between the two metal components, the enhanced basic active sites and the active surface area.
- Jiang, Jiusheng,Li, Xiang,Du, Shengyu,Shi, Langchen,Jiang, Pingping,Zhang, Pingbo,Dong, Yuming,Leng, Yan
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p. 7780 - 7785
(2020/06/09)
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- Palladium-Catalyzed, Copper(I)-Promoted Methoxycarbonylation of Arylboronic Acids with O-Methyl S-Aryl Thiocarbonates
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Here, we report O-methyl S-aryl thiocarbonates as a versatile esterification reagent for palladium-catalyzed methoxycarbonylation of arylboronic acid in the presence of copper(I) thiophene-2-carboxylate (CuTC). The reaction condition is mild, and a variety of substituents including sensitive-Cl,-Br, and free-NH2 could be tolerated. Further applications in the late-stage esterification of some pharmaceutical drugs demonstrate the broad utility of this method.
- Cao, Ya-Fang,Li, Ling-Jun,Liu, Min,Xu, Hui,Dai, Hui-Xiong
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p. 4475 - 4481
(2020/04/10)
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- Fluorinations of unsymmetrical diaryliodonium salts containing: Ortho -sidearms; Influence of sidearm on selectivity
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Activated aromatics were reacted with two different fluoroidoane reagents 1 and 2 in the presence of triflic acid to prepare only the para-substituted diaryliodonium salts. With fluoroiodane 1 the unsymmetrical diaryliodonium salts contained an ortho-propan-2-ol sidearm, whereas the alcohol sidearm was eliminated to form an ortho-styrene sidearm in the reaction with fluoroiodane 2. Only the diaryliodonium salts containing a styrene sidearm were fluorinated successfully to deliver para-fluorinated aromatics in good yields.
- Abudken, Ahmed M. H.,Hope, Eric G.,Singh, Kuldip,Stuart, Alison M.
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supporting information
p. 6140 - 6146
(2020/10/30)
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- Aldehydes as potential acylating reagents for oxidative esterification by inorganic ligand-supported iron catalysis
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The oxidative esterification of various aldehydes with alcohols could be achieved by a heterogeneous iron(iii) catalyst supported on a ring-like POM inorganic ligand under mild conditions, affording the corresponding esters, including several drug molecules and natural products, in high yields. ESI-MS and control experiments demonstrated that POM-FeV(O) was the active catalytic species and the plausible mechanism was presented. More importantly, the 6th run of the iron catalyst recycles shows only a slight decrease in the yield.
- Yu, Han,Wang, Jingjing,Wu, Zhikang,Zhao, Qixin,Dan, Demin,Han, Sheng,Tang, Jiangjiang,Wei, Yongge
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supporting information
p. 4550 - 4554
(2019/08/21)
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- 1,3-Dibromo-5,5-dimethylhydantoin as a Precatalyst for Activation of Carbonyl Functionality
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Activation of carbonyl moiety is one of the most rudimentary approaches in organic synthesis and is crucial for a plethora of industrial-scale condensation reactions. In esterification and aldol condensation, which represent two of the most important reactions, the susceptibility of the carbonyl group to nucleophile attack allows the construction of a variety of useful organic compounds. In this context, there is a constant need for development of and improvement in the methods for addition-elimination reactions via activation of carbonyl functionality. In this paper, an advanced methodology for the direct esterification of carboxylic acids and alcohols, and for aldol condensation of aldehydes using widely available, inexpensive, and metal-free 1,3-dibromo-5,5-dimethylhydantoin under neat reaction conditions is reported. The method is air- and moisture-tolerant, allowing simple synthetic and isolation procedures for both reactions presented in this paper. The reaction pathway for esterification is proposed and a scale-up of certain industrially important derivatives is performed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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supporting information
(2019/08/01)
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- A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
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Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
- Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
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p. 3931 - 3943
(2018/09/11)
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- Structural design, synthesis and substituent effect of hydrazone-N-acylhydrazones reveal potent immunomodulatory agents
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4-(Nitrophenyl)hydrazone derivatives of N-acylhydrazone were synthesized and screened for suppress lymphocyte proliferation and nitrite inhibition in macrophages. Compared to an unsubstituted N-acylhydrazone, active compounds were identified within initial series when hydroxyl, chloride and nitro substituents were employed. Structure-activity relationship was further developed by varying the position of these substituents as well as attaching structurally-related substituents. Changing substituent position revealed a more promising compound series of anti-inflammatory agents. In contrast, an N-methyl group appended to the 4-(nitrophenyl)hydrazone moiety reduced activity. Anti-inflammatory activity of compounds is achieved by modulating IL-1β secretion and prostaglandin E2 synthesis in macrophages and by inhibiting calcineurin phosphatase activity in lymphocytes. Compound SintMed65 was advanced into an acute model of peritonitis in mice, where it inhibited the neutrophil infiltration after being orally administered. In summary, we demonstrated in great details the structural requirements and the underlying mechanism for anti-inflammatory activity of a new family of hydrazone-N-acylhydrazone, which may represent a valuable medicinal chemistry direction for the anti-inflammatory drug development in general.
- Meira, Cássio S.,dos Santos Filho, José Maurício,Sousa, Caroline C.,Anjos, Pamela S.,Cerqueira, Jéssica V.,Dias Neto, Humberto A.,da Silveira, Rafael G.,Russo, Helena M.,Wolfender, Jean-Luc,Queiroz, Emerson F.,Moreira, Diogo R.M.,Soares, Milena B.P.
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p. 1971 - 1985
(2018/03/12)
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- Oxalic acid as the: In situ carbon monoxide generator in palladium-catalyzed hydroxycarbonylation of arylhalides
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An efficient palladium-catalyzed hydroxycarbonylation reaction of arylhalides using oxalic acid as a CO source has been developed. The reaction features high safety, low catalyst loading, and a broad substrate scope, and provides a safe and tractable approach to access a variety of aromatic carboxylic acid compounds. Mechanistic studies revealed the decomposition pattern of oxalic acid.
- Shao, Changdong,Lu, Ailan,Wang, Xiaoling,Zhou, Bo,Guan, Xiaohong,Zhang, Yanghui
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p. 5033 - 5040
(2017/07/10)
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- Heterogeneous cobalt catalysts for selective oxygenation of alcohols to aldehydes, esters and nitriles
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Efficient and green oxygenation of alcohols to the corresponding aldehydes, esters and nitriles was developed with high selectivity. Functional alcohols, including some heterocyclic and allylic alcohols can be oxygenated to the corresponding aldehydes, esters and nitriles respectively. Moreover, the catalyst can be recycled and reused without significant deactivation. Noteworthy, the Co@NC (800-2h) catalyzed oxygenation of alcohols can be regulated easily by changing the reaction conditions, and then the corresponding aldehydes, esters and nitriles can be obtained in high yields respectively.
- Mao, Fei,Qi, Zhengliang,Fan, Haipeng,Sui, Dejun,Chen, Rizhi,Huang, Jun
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p. 1498 - 1503
(2017/01/18)
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- Synthesis and Biological Evaluation of New (-)-Gossypol-Derived Schiff Bases and Hydrazones
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A series of 14 new (-)-gossypol Schiff bases and hydrazones have been synthesized via an in situ procedure in high yields. Structural data showed that all target compounds exist as the enamine tautomer. Bioassays showed that several compounds exhibited cytotoxic effects against three human cancer cell lines. Compound 8a showed the greatest cytotoxic effect against hepatocellular carcinoma (HepG2), lung carcinoma (LU-1), and breast cancer (MCF-7) cell lines with IC50 values of 20.93, 13.58, and 9.40 μM, respectively. However, in an antibacterial test, compounds 8a and 8b inhibited Staphylococcus aureus and Bacillus cereus and compound 8e inhibited only Staphylococcus aureus at the same MIC values of 1024 μg/ml.
- Vu, Vu Van,Nhung, Trinh Thi,Thanh, Nguyen Thi,Chinh, Luu Van,Tien, Vu Dinh,Thuy, Vu Thu,Thi Thao, Do,Nam, Nguyen Hai,Koeckritz, Angela,Vu, Tran Khac
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- Chemoselective dehydrogenative esterification of aldehydes and alcohols with a dimeric rhodium(II) catalyst
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Dehydrogenative cross-coupling of aldehydes with alcohols as well as dehydrogentive cross-coupling of primary alcohols to produce esters have been developed using a Rh-terpyridine catalyst. The catalyst demonstrates broad substrate scope and good functional group tolerance, affording esters highly selectively. The high chemoselectivity of the catalyst stems from its preference for dehydrogenation of benzylic alcohols over aliphatic ones. Preliminary mechanistic studies suggest that the active catalyst is a dimeric Rh(ii) species, operating via a mechanism involving metal-base-metal cooperativity.
- Cheng, Junjie,Zhu, Meijuan,Wang, Chao,Li, Junjun,Jiang, Xue,Wei, Yawen,Tang, Weijun,Xue, Dong,Xiao, Jianliang
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p. 4428 - 4434
(2016/07/07)
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- Design, synthesis and antibacterial activity of isatin derivatives as FtsZ inhibitors
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Seven isatin derivatives have been designed, and their chemical structures were characterized by single crystal X-ray diffraction studies, 1H NMR, MS, and elemental analysis. Structural stabilization followed by intramolecular as well as intermolecular H-bonds makes these molecules as perfect examples in molecular recognition with self-complementary donor and acceptor units within a single molecule. These compounds were evaluated for antimicrobial activities. Docking simulations have been performed to position compounds into the FtsZ active site to determine their probable binding models. All of the compounds exhibited better antibacterial activities. Interestingly, compound 5c and 5d exhibited better antibacterial activities with IC50 values of 0.03 and 0.05 μmol/mL against Staphylococcus aureus, respectively. Compound 5g displays antibacterial activity with IC50 values of 0.672 and 0.830 μmol/mL against Escherichia coli and Pseudomonas aeruginosa, respectively.
- Lian, Zhi-Min,Sun, Juan,Zhu, Hai-Liang
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- Synthesis and biological evaluation of novel resveratrol-oxadiazole hybrid heterocycles as potential antiproliferative agents
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A novel class of resveratrol-oxadiazole hybrid compounds was synthesized to screen for their in vitro antiproliferative activity against three human cancer cell lines. All the compounds showed superior antiproliferative activity than the reference compound resveratrol. The most promising active compounds in this series were 1g, 2g, 1c, 2c, 2i and 1a (GI50 0.1 μM), endowed with excellent antiproliferative activity. Thus, we believe that resveratrol-oxadiazole hybrid compounds may possibly be used as a good leads for the development of new antiproliferative agents. Structures of newly synthesized compounds were confirmed by NMR and IR spectral data.
- Murty,Penthala, Raju,Polepalli, Sowjanya,Jain
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p. 627 - 643
(2016/03/08)
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- Antiurease, antiphosphodiesterase and antiglycation studies of Pd(II) complexes with monodentate hydrazides
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The present study was aimed to synthesize and characterize a series of Pd(II)-benzohydrazide complexes with subsequent high throughput screening to seek their effects as enzyme inhibitors and antiglycating agents. Based on complete characterization via elemental (CHN, Pd) analysis, physical (conductivity, magnetic moment) measurements and spectral (FT-IR, 1H-NMR, 13C-NMR) techniques, all Pd(II) complexes were identified as diamagnetic, neutral and orienting in trans square planar geometry with general formula [PdL2Cl2]. The benzohydrazide (L) in these complexes depicts monodentate behavior, providing terminal amino nitrogen as a donor atom. Compared to inactive precursors (free benzohydrazides and Pd2+), almost all Pd(II) complexes showed in vitro antiglycation activity, illustrating the potential role of resulting complexes in the suppression of diabetes and related disorders. The presence of free carbonyl group in complexes has been recognized as possible cause of antiglycation. This study also indicated Pd(II) compounds as far more superior inhibitors of urease and phosphodiesterase-I than parent ligands; many of them exhibited inhibitions equivalent or even greater than the standard inhibitors (thiourea, urease; EDTA, phosphodiesterase), which shows their potential use in future in the control of peptic ulcer and arthritis, respectively. The structure activity relationship (SAR) study demonstrated that complexation, steric hindrance, position of substituents, electron density around metal centre, hydrogen bonding and coordination mode of complexed ligands play prime role in modulating the biological activities of complexes.
- Qurrat-Ul-Ain,Rasheed, Saima,Mahroof-Tahir, Mohammad,Ashiq, Uzma,Jamal, Rifat Ara,Khurshid, Sumaira,Mustafa, Sana
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p. 864 - 881
(2016/11/21)
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- Oxygen-Controlled Catalysis by Vitamin B12-TiO2: Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation
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An oxygen switch in catalysis of the cobalamin derivative (B12)-TiO2 hybrid catalyst for the dechlorination of trichlorinated organic compounds has been developed. The covalently bound B12 on the TiO2 surface transformed trichlorinated organic compounds into an ester and amide by UV light irradiation under mild conditions (in air at room temperature), while dichlorostilbenes (E and Z forms) were formed in nitrogen from benzotrichloride. A benzoyl chloride was formed as an intermediate of the ester and amide, which was detected by GC-MS. The substrate scope of the synthetic strategy is demonstrated with a range of various trichlorinated organic compounds. A photo-duet reaction utilizing the hole and conduction band electron of TiO2 in B12-TiO2 for the amide formation was also developed.
- Shimakoshi, Hisashi,Hisaeda, Yoshio
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supporting information
p. 15439 - 15443
(2016/01/26)
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- Iron oxalate capped iron-copper nanomaterial for oxidative transformation of aldehydes
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An efficient, sustainable and green procedure for the synthesis of selective orthorhombic iron(oxalate) capped Fe-Cu bimetallic oxide nanomaterial [Fe(ox)Fe-CuOx] was developed using a sodium borohydride reduction of iron(ii) salt in the presence of oxalic acid at room temperature followed by addition of copper sulfate in water. The reported method is a cost-effective chemical route for producing [Fe(ox)Fe-CuOx] nano material at the gram level with a surface area of 78.4 m2 g-1 and a pore volume of 0.141 cm3 g-1. The [Fe(ox)Fe-CuOx] nanomaterials were found to be useful as a recoverable catalyst for the oxidative transformation of an aldehyde to its corresponding ester and acid in presence of hydrogen peroxide.
- Kashyap, Rajarshi,Talukdar, Dhruba Joyti,Pratihar, Sanjay
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p. 1430 - 1437
(2015/02/19)
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- DMSO/I2 mediated C-C bond cleavage of α-ketoaldehydes followed by C-O bond formation: A metal-free approach for one-pot esterification
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A novel and efficient I2/DMSO mediated metal-free strategy is presented for the direct C-C bond cleavage of aryl-/heteroaryl- or aliphatic α-ketoaldehydes by C2-decarbonylation and C1-carbonyl oxidation to give the corresponding carboxylic acids followed by esterification in one pot, offering excellent yields in both the steps. Here, DMSO acts as the oxygen source/oxidant and this reaction works very well under both conventional heating and microwave irradiation. This is a very simple and convenient protocol.
- Venkateswarlu, Vunnam,Aravinda Kumar,Gupta, Sorav,Singh, Deepika,Vishwakarma, Ram A.,Sawant, Sanghapal D.
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p. 7973 - 7978
(2015/07/27)
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- Synthesis, anti-HIV activity and Molecular modeling study of 3-aryl-6-adamantylmethyl-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazole derivatives
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A series of novel 3-aryl-6-adamantylmethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 6a-l were synthesized by a simple method with the aim of developing novel HIV non-nucleoside reverse transcriptase inhibitors. All the synthesized compounds were structurally confirmed by spectral analyses. The structure of 6a was unambiguously verified by X-ray structure determination. The synthesized compounds were evaluated for their anti-HIV activity and four analogs displayed moderate inhibitory activity with EC50 values ranging from 10.10 to 12.40 μg mL-1. Molecular docking of 6g with HIV-1 reverse transcriptase was studied to rationalize some structureactivity relationships (SARs).
- Khan, Mahmood-Ul-Hassan,Hameed, Shahid,Farman, Muhammad,Al-Masoudia, Najim A.,Stoeckli-Evans, Helen
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p. 609 - 616
(2016/02/18)
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- A catalytic borylation/dehalogenation route to o -fluoro arylboronates
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A two-step Ir-catalyzed borylation/Pd-catalyzed dehalogenation sequence allows for the net synthesis of fluoroarenes where the boronic ester is ortho to fluorine. Key elements of this approach include the use of a halogen para to the fluorine to block meta Ir-catalyzed borylation and the chemoselective Pd-catalyzed dehalogenation by KF activated polymethylhydrosiloxane (PMHS).
- Jayasundara, Chathurika R. K.,Unold, Jason M.,Oppenheimer, Jossian,Smith, Milton R.,Maleczka, Robert E.
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p. 6072 - 6075
(2015/01/09)
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- Copper-catalyzed decarboxylative methylation of aromatic carboxylic acids with PhI(OAc)2
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The copper-catalyzed decarboxylative methylation of aromatic carboxylic acids was developed by using PhI(OAc)2 to provide a new strategy for the methylation of aryl acids through the decarboxylation of alkyl acids. The mechanism and the roles of each reactant in the reaction were investigated extensively. Copyright
- Jiang, Yuyu,Pan, Shulei,Zhang, Yanghui,Yu, Jingxun,Liu, Hongqiang
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supporting information
p. 2027 - 2031
(2014/04/17)
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- Synthesis and evaluation of novel azoles as potent antifungal agents
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Using a rational approach to the design of antifungal agents, a series of azole agents with 1,3,4-oxadiazole side chains were designed and synthesized. The results of preliminary in vitro antifungal tests with eight human pathogenic compounds showed that all of the title compounds exhibited excellent activities against all of the tested fungi except Aspergillus fumigatus. Compounds 11e and 11f were found to be the most effective, with a minimum inhibitory concentration of 0.0039 μg/mL, followed by voriconazole, which has a MIC of 0.0625 μg/mL. The 1,3,4-oxadiazole side chain is not the major contributor but plays a role in eliciting the observed antifungal activity.
- Li, Liangjing,Ding, Hao,Wang, Baogang,Yu, Shichong,Zou, Yan,Chai, Xiaoyun,Wu, Qiuye
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supporting information
p. 192 - 194
(2014/01/17)
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- Synthesis, spectroscopic and radical scavenging studies of palladium(II)-hydrazide complexes
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In present study, a series of palladium(II) complexes with biologically active hydrazide ligands have been synthesized, characterized and screened for their antioxidant (superoxide and DPPH radical scavenging) properties. Spectral studies (FT-IR, EI-mass, 13C and 1H NMR spectroscopy) and physico-chemical measurements including elemental analysis, magnetic susceptibility and conductivity measurements represented square planar structure for all complexes. Substituted and unsubstituted benzohydrazides (1-4) have shown monodentate behavior forming complexes of general formula [PdL 2Cl2]. However, pyridine-carbohydrazides (5 and 6) were coordinated in bidentate fashion of [PdLCl2] general formula producing stable five-membered chelate ring. All palladium complexes were found to be considerably more potent inhibitors of DPPH free radical compared to free hydrazides. These complexes are even stronger DPPH scavengers than standard antioxidant propyl gallate. The complexes have also shown good superoxide scavenging ability compared to inactive free hydrazides, however complexes are weaker superoxide scavengers than ascorbic acid, a standard superoxide inhibitor. An interesting structure activity relationship has been evaluated.
- Ain, Qurrat Ul,Ashiq, Uzma,Jamal, Rifat Ara,Mahrooof-Tahir, Mohammad
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p. 683 - 689
(2013/11/06)
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- Synthesis, antibacterial activities, and 3d-qsar of sulfone derivatives containing 1, 3, 4-oxadiazole moiety
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A series of sulfone derivatives containing 1, 3, 4-oxadiazole moiety were prepared and evaluated for their antibacterial activities by the turbidimeter test. Most compounds inhibited growth of Ralstonia solanacearum (R. solanacearum) from tomato and tobacco bacterial wilt with high potency, among which compounds 5a and 5b exhibited the most potent inhibition against R. solanacearum from tomato and tobacco bacterial wilts with EC50 values of 19.77 and 8.29 μg/mL, respectively. Our results also demonstrated that 5a, 5b, and a number of other compounds were more potent than commercial bactericides Kocide 3000 and Thiodiazole Copper, which inhibited R. solanacearum from tomato bacterial wilt with EC50 values of 93.59 and 99.80 μg/mL and tobacco bacterial wilt with EC50 values of 45.91 and 216.70 μg/mL, respectively. The structure-activity relationship (SAR) of compounds was studied using three-dimensional quantitative structure-activity relationship (3D-QSAR) models created by comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) based on compound bioactivities against tomato and tobacco bacterial wilts. The 3D-QSAR models effectively predicted the correlation between inhibitory activity and steric-electrostatic properties of compounds.
- Li, Pei,Yin, Juan,Xu, Weiming,Wu, Jian,He, Ming,Hu, Deyu,Yang, Song,Song, Baoan
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p. 546 - 556
(2013/11/06)
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- Hydrosilane and bismuth-accelerated palladium catalyzed aerobic oxidative esterification of benzylic alcohols with air
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In a palladium-catalyzed oxidative esterification, hydrosilane can serve as an activator of palladium catalyst with bismuth, thus leading to a novel ligand- and silver-free palladium catalyst system for facile oxidative esterification of a variety of benzylic alcohols in good yields.
- Bai, Xing-Feng,Ye, Fei,Zheng, Long-Sheng,Lai, Guo-Qiao,Xia, Chun-Gu,Xu, Li-Wen
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supporting information; experimental part
p. 8592 - 8594
(2012/09/21)
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- A general and efficient zinc-catalyzed oxidation of benzyl alcohols to aldehydes and esters
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Go green: A general and efficient zinc-catalyzed oxidation of benzyl alcohols has been developed. In the presence of a zinc catalyst, various aldehydes and esters have been prepared in good to excellent yields under mild conditions (see scheme).
- Wu, Xiao-Feng
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experimental part
p. 8912 - 8915
(2012/09/22)
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- Titration of nonstabilized diazoalkane solutions by fluorine NMR
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A new protocol for titrating nonstabilized diazoalkane solutions by quantitative 19F NMR is reported. An excess of 2-fluorobenzoic acid dissolved in CDCl3 is treated with the diazoalkane solution at a low temperature, immediately forming the corresponding 2-fluorobenzoate ester upon warming. A significant difference in the 19F chemical shift between the ester and acid is seen, allowing facile and accurate integration to determine titer. The procedure is safe, rapid, and indicates the active diazoalkane concentration with high precision.
- Rendina, Victor L.,Kingsbury, Jason S.
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experimental part
p. 1181 - 1185
(2012/03/12)
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- Synthesis, biological evaluation and molecular docking studies of novel 2-(1,3,4-oxadiazol-2-ylthio)-1-phenylethanone derivatives
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In present study, a series of new 2-(1,3,4-oxadiazol-2-ylthio)-1- phenylethanone derivatives (6a-6x) as potential focal adhesion kinase (FAK) inhibitors were synthesized. The bioassay assays demonstrated that compound 6i showed the most potent activity, which inhibited the growth of MCF-7 and A431 cell lines with IC50 values of 140 ± 10 nM and 10 ± 1 nM, respectively. Compound 6i also exhibited significant FAK inhibitory activity (IC50 = 20 ± 1 nM). Docking simulation was performed to position compound 6i into the active site of FAK to determine the probable binding model.
- Zhang, Li-Rong,Liu, Zhi-Jun,Zhang, Hui,Sun, Jian,Luo, Yin,Zhao, Ting-Ting,Gong, Hai-Bin,Zhu, Hai-Liang
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scheme or table
p. 3615 - 3621
(2012/07/27)
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- Synthesis, crystal structure and anti-HIV activity of 2-adamantyl/ adamantylmethyl-5-aryl-1,3,4-oxadiazoles
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Two series of 2-adamantyl/adamantylmethyl-5-aryl-1,3,4-oxadiazoles (4a-l and 5a-l) were synthesized by cyclodehydration of adamantan-1-carboxylic acid/adamantylacetic acid with various aryl hydrazides (3a-l) in the presence of POCl3. The synthesis was supported by spectroanalytical techniques and verified further by crystal structure determination of compounds 4e and 5k. The synthesized compounds were screened for their inhibitory activity against HIV-1 and HIV-2 in MT-4 cells. Compound 5b exhibited a moderate activity in vitro for the replication of both virus types, suggesting for further structural modification as a new lead in the development of an antiviral agent.
- Khan, Mahmood-Ul-Hassan,Hameed, Shahid,Akhtar, Tashfeen,Al-Masoudi, Najim A.,Stoeckli-Evans, Helen
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p. 1190 - 1197,8
(2012/12/12)
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- Synthesis, crystal structure and anti-HIV activity of 2-adamantyl/ adamantylmethyl-5-aryl-1,3,4-oxadiazoles
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Two series of 2-adamantyl/adamantylmethyl-5-aryl-1,3,4-oxadiazoles (4a-l and 5a-l) were synthesized by cyclodehydration of adamantan-1-carboxylic acid/adamantylacetic acid with various aryl hydrazides (3a-l) in the presence of POCl3. The synthesis was supported by spectroanalytical techniques and verified further by crystal structure determination of compounds 4e and 5k. The synthesized compounds were screened for their inhibitory activity against HIV-1 and HIV-2 in MT-4 cells. Compound 5b exhibited a moderate activity in vitro for the replication of both virus types, suggesting for further structural modification as a new lead in the development of an antiviral agent.
- Khan, Mahmood-Ul-Hassan,Akhtar, Tashfeen,Al-Masoudi, Najim A.,Stoeckli-Evans, Helen,Hameed, Shahid
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p. 1190 - 1197
(2013/01/15)
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- Palladium- or nickel-catalyzed coupling reaction of dialkoxyboranes with chloroarenes: arylation of 1,3,2-dioxaborolanes or l,3,2-dioxaborinanes
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The borylation of electron-deficient aryl chlorides with pinacolborane proceeded in the presence of BU4NI and a catalytic amount of Pd(dba)2 / bis(2-di-tert-butylphosphinophenyl) ether. The combination of NiCl2(dppp) catalyst and Bu4NBr was also efficient for the borylation of aryl chlorides.
- Murata, Miki,Sambommatsu, Tomoko,Oda, Takeshi,Watanabe, Shinji,Masuda, Yuzuru
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experimental part
p. 213 - 218
(2010/05/03)
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- Anion binding of N-(o-Methoxybenzamido)thioureas: Contribution of the intramolecular hydrogen bond in the N-benzamide moiety
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N-(o-Methoxybenzamido)- thioureas (2X/2Y) are found to show an enhanced anion binding affinity with binding constants over 107 mol -1L orders of magnitude for AcO- and a redshifted absorption of the anion binding complexes in acetonitrile (MeCN) relative to those of N-benzamidothioureas (1) that bear no o- OMe in the N-benzamide moiety, despite the electron-donating character of o-OMe. Absorption of the anion-2X/ 2Y complex was shown to be of the same charge-transfer nature as that of the anion-1 complex, but its dependence on substituent X is interestingly influenced by the o-MeO···HNC=O six-membered-ring intramolecular hydrogen bond identified in 2X/2Y. Such an intramolecular hydrogen bond is suggested to be responsible for the enhanced anion binding affinity. In the presence of this intramolecular hydrogen bond, the anion binding constant of 2X was found to be independent of substituent X at the N-phenyl ring, as in the case of 1, whereas that of 2Y showed an amplified dependence on substituent Y at the N′-phenyl ring, but to a lower extent than that of 1. A similar ring intramolecular hydrogen bond was purported to exist in 2Za, 2Zd, and 2Ze, which bear NHMe, F, and Cl as the ortho substituent in the N-benzamide moiety. In terms of the current roles of thiourea in not only anion recognition and sensing but also organocatalysis and crystal engineering, the present finding would be of significance for a wider structural diversity of smart thiourea derivatives with predesigned functions.
- Jiang, Qian-Qian,Darhkijav, Burenkhangai,Liu, Hao,Wang, Fang,Li, Zhao,Jiang, Yun-Bao
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experimental part
p. 543 - 549
(2010/08/20)
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- Synthesis, crystal structure and antiproliferative activity of 6-adamantyl-3-aryl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles
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A series of 3,6-disubstituted [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a - l bearing an adamantyl moiety were synthesized by condensation of 4-amino-5-aryl-2H-1,2,4-triazole-3(4H)-thiones 4a - l with adamantyl-1- carboxylic acid in the presence of POCl3. The structures of the newly synthesized compounds were established using spectroanalytical techniques and verified further by the crystal structure determination of compounds 5a and 5j. The compounds were screened for their antiproliferative activity against a large panel of human cell lines.
- Khan, Mahmood-Ul-Hassan,Akhtar, Tashfeen,Yasin, Khawaja A.,Al-Masoudi, Najim A.,Jones, Peter G.,Hameed, Shahid
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scheme or table
p. 178 - 184
(2010/08/22)
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- Design, synthesis, and urease inhibition studies of a series of 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones
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A series of 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones was synthesized by reaction of aryl hydrazides with CS2 and hydrazine hydrate. The synthesized compounds were characterized by spectroanalytical techniques, and their urease inhibition activity was evaluated using jack bean urease. All but one of the synthesized compounds were active, and two of them were found to be more potent than the standard, with 50% inhibition concentration (IC 50) values of 17.5 ± 0.52 and 4.3 ± 0.169 μM, respectively (standard IC 50 = 21.0 ± 0.11 μM). Tentative statements regarding the role of different functional groups in binding to the enzyme active site are also presented.
- Khan, Mahmood-Ul-Hassan,Hameed, Shahid,Yasin, Khawaja A.,Akhtar, Tashfeen,Khan, Khalid M.
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scheme or table
p. 479 - 484
(2011/08/03)
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- Exploration and optimization of substituted triazolothiadiazines and triazolopyridazines as PDE4 inhibitors
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An expansion of structure-activity studies on a series of substituted 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine PDE4 inhibitors and the introduction of a related [1,2,4]triazolo[4,3-b]pyridazine based inhibitor of PDE4 is presented. The development of SAR included strategic incorporation of known substituents on the critical catachol diether moiety of the 6-phenyl appendage on each heterocyclic core. From these studies, (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine (10) and (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-[1,2,4]triazolo[4,3-b]pyridazine (18) were identified as highly potent PDE4A inhibitors. Each of these analogues was submitted across a panel of 21 PDE family members and was shown to be highly selective for PDE4 isoforms (PDE4A, PDE4B, PDE4C, PDE4D). Both 10 and 18 were then evaluated in divergent cell-based assays to assess their relevant use as probes of PDE4 activity. Finally, docking studies with selective ligands (including 10 and 18) were undertaken to better understand this chemotypes ability to bind and inhibit PDE4 selectively.
- Skoumbourdis, Amanda P.,LeClair, Christopher A.,Stefan, Eduard,Turjanski, Adrian G.,Maguire, William,Titus, Steven A.,Huang, Ruili,Auld, Douglas S.,Inglese, James,Austin, Christopher P.,Michnick, Stephen W.,Xia, Menghang,Thomas, Craig J.
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supporting information; experimental part
p. 3686 - 3692
(2010/03/24)
-
- Carboxylation and esterification of functionalized arylcopper reagents
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Functionalized arylcopper reagents have been produced in good yields at 25 °C from activated copper and the corresponding functionalized aryl iodides without the need of traditional organolithium or Grignard precursors. These organocopper compounds will undergo carboxylation with CO2 to form the corresponding copper benzoates. In turn, these salts can be acidified to produce the functionalized aryl acids or treated with appropriate alkyl halides in the presence of a dipolar aprotic solvent to generate the corresponding aryl esters. This methodology permits the formation of functionalized organic acids and esters that could not be generated by the carboxylation of organomagnesium compounds.
- Ebert, Greg W.,Juda, Wayne L.,Kosakowski, Robert H.,Ma, Bing,Dong, Liming,Cummings, Keith E.,Phelps, Mwita V. B.,Mostafa, Adel E.,Luo, Jianyuan
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p. 4314 - 4317
(2007/10/03)
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- Novel C-C bond cleavage under mild, neutral conditions: Conversion of electron-deficient aryl alkyl ketones to aryl carboxylic esters
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A novel, unique way to cleave the carbon-carbon bond in aryl alkyl ketones under mild, neutral conditions is described. Treatment of aryl alkyl ketones in a refluxing mixture of N,N-dimethylformamide dimethyl acetal and methanol for 16 h provided aryl car
- Zhang, Nan,Vozzolo, Joseph
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p. 1703 - 1704
(2007/10/03)
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- Method for preparing aromatic compounds
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A method for synthesizing aromatic compounds by selectively dehalogenating aromatic starting materials is provided. Compounds may be prepared which are substituted with fluoro, chloro or bromo. The method may be used to remove halogen atoms from sites at which halogenation is not desired, and to form substantially pure halogenated compounds from mixtures of starting materials. The method uses a copper containing dehalogenation agent and an acid with the dehalogenation being controlled by a substituent such as a carboxylic acid, amide, ester, aldehyde, ketone or cyano on the aromatic ring.
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- Method for preparing aromatic compounds
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A method for synthesizing aromatic compounds by selectively dehalogenating aromatic starting materials is provided. Compounds may be prepared which are substituted with fluoro, chloro or bromo. The method may be used to remove halogen atoms from sites at which halogenation is not desired, and to form substantially pure halogenated compounds from mixtures of starting materials. The method uses a copper containing dehalogenation agent and an acid with the dehalogenation being controlled by a substituent such as a carboxylic acid, amide, ester, aldehyde, ketone or cyano on the aromatic ring.
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- A New Indirect Application of Aggregative Activation: Synthesis of Esters by Cobalt-Catalyzed Carbonylation of Aryl, Heterocyclic, and Vinyl Halides under Atmospheric Pressure
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Sun lamp illuminated alkoxycarbonylation of aryl, heteroaryl, and vinyl halides was performed under atmospheric pressure of CO in the presence of a cobalt catalyst in situ generated from Co(OAc)2.Illunination through a Pyrex flask was sufficient to catalyze the reaction.This process avoids the use of Co2(CO)8 and excess CH3I, which were required in the earlier procedure.A SRN1 mechanism is proposed.
- Marchal, Joel,Bodiguel, Jacques,Fort, Yves,Caubere, Paul
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p. 8336 - 8340
(2007/10/02)
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- KINETICS OF METHANOLYSIS OF 1-(2-HALOGENO AND 2,6-DIHALOGENOBENZOYL)-3-(4-CHLOROPHENYL)UREAS
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The methanolysis kinetics has been measured of 1-(2,6-difluorobenzoyl)-3-(4-chlorophenyl)urea (a larvicidal insecticide Dimilin) and of four other mono- and dihalogenobenzoyl derivatives.Polar and steric effects of halogen on the rate and dissociation constants is discussed.
- Kavalek, Jaromir,Kacetl, Lubomir,Kavalkova, Marcela
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p. 1363 - 1369
(2007/10/02)
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- 1,2,4,6-CYCLOHEPTATETRAENE: THE KEY INTERMEDIATE IN ARYLCARBENE INTERCONVERSIONS AND RELATED C7H6 REARRANGEMENTS
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Thermolysis or photolysis of phenyldiazomethane (2) produces phenylmethylene (3), which ring-expands to give 1,2,4,6-cycloheptatetraene (6).Spectroscopic and chemical evidence rule out bicyclo(4.1.0)hepta-2,4,6-triene (4), cycloheptatrienylidene (5), and bicyclo(3.2.0)hepta-1,3,6-triene (11) intermediates.The strained allene in cycloheptatetraene (6) exhibits infrared absorption at 1824 and 1816 cm-1.Deuterium substitution produces the expected 10-cm-1 shift in the allene absorption.Fluorine or chlorine substitution substantially enhances the allene absorption intensity.Deuterium labeling studies reveal that the intramolecular chemistry of cycloheptatetraene (6) involves reversible thermal or photochemical equilibriation with phenylmethylene (3).The intermolecular chemistry of 6 involves dimerization.At temperatures as low as 10 K, 6 forms a labile (2+2) dimer,7, which undergoes thermally allowed, electrocyclic ring opening to give heptafulvalene (8) upon warming to room temperature.The rearrangements of 7-acetoxynorbornadiene (9), 2-diazobicyclo(3.2.0)hepta-3,6-diene (31), and 8-diazobicyclo(2.2.2)octa-2,5-dien-7-one (33) all involve cycloheptatetraene (6) intermediates.
- McMahon, Robert J.,Abelt, Christopher J.,Chapman, Orville L.,Johnson, Jeffery W.,Kreil, Curits L.,et al.
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p. 2456 - 2469
(2007/10/02)
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- Antidepressant activity of 5-aryl-2,3,5,6-tetrahydroimidazo[2,1-a]isoquinolin-5-ols
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A series of 5-aryl-2,3,5,6-tetrahydroimidazo[2,1-a]isoquinolin-5-ols was prepared and evaluated for potential antidepressant activity in the reserpine-induced hypothermia model and selected central nervous system and autonomic activity tests. Several members of the series, notably the 4-chloro- and 4-fluorophenyl analogues, demonstrated pharmacological activity in the range of imipramine. Both compounds provided a marked potentiation of the 5-hydroxytryptophan-facilitated monosynaptic spike in the spinal cat preparation.
- Houlihan,Gogerty,Parrino,Ryan
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p. 765 - 768
(2007/10/02)
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- Applicability of Hammett Equation to Kinetics of Acid-catalysed Esterification of ortho-Substituted Phenoxyacetic, Phenylmercaptoacetic and Phenylsulphonylacetic Acids by Methanol
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Correlation analysis of the title rate data shows that the steric effects of ortho-substituents are absent at the reaction centre.
- Baliah, V.,Gurumurthy, R.
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p. 257 - 258
(2007/10/02)
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- Reaction of Fluoroxysulfate with Aromatic Compounds
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The fluoroxysulfate ion, SO4F-, substitutes fluorine on aromatic compounds in acetonitrile solution at room temperature.However, benzylfluoride is the principal product from toluene.Other products are also formed, particularly in the case of the less reactive aromatic substrates.Product distributions and relative reactivities are interpreted in terms of an initial electophilic attack that can be followed by free-radical side reactions.
- Ip, Dominic P.,Arthur, Carol D.,Winans, Randall E.,Appelman, Evan H.
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p. 1964 - 1968
(2007/10/02)
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