- Oxidative Coupling of Aldehydes with Alcohol for the Synthesis of Esters Promoted by Polystyrene-Supported N-Heterocyclic Carbene: Unraveling the Solvent Effect on the Catalyst Behavior Using NMR Relaxation
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Heterogeneous organocatalysts hold great potential as they offer practical advantages in terms of purification and reusability compared with the homogeneous counterpart. A puzzling aspect is the solvent effect on their catalytic performance. Here we propo
- Di Carmine, Graziano,Ragno, Daniele,Massi, Alessandro,D'agostino, Carmine
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- A Convenient and Stable Heterogeneous Nickel Catalyst for Hydrodehalogenation of Aryl Halides Using Molecular Hydrogen
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Hydrodehalogenation is an effective strategy for transforming persistent and potentially toxic organohalides into their more benign congeners. Common methods utilize Pd/C or Raney-nickel as catalysts, which are either expensive or have safety concerns. In this study, a nickel-based catalyst supported on titania (Ni-phen@TiO2-800) is used as a safe alternative to pyrophoric Raney-nickel. The catalyst is prepared in a straightforward fashion by deposition of nickel(II)/1,10-phenanthroline on titania, followed by pyrolysis. The catalytic material, which was characterized by SEM, TEM, XRD, and XPS, consists of nickel nanoparticles covered with N-doped carbon layers. By using design of experiments (DoE), this nanostructured catalyst is found to be proficient for the facile and selective hydrodehalogenation of a diverse range of substrates bearing C?I, C?Br, or C?Cl bonds (>30 examples). The practicality of this catalyst system is demonstrated by the dehalogenation of environmentally hazardous and polyhalogenated substrates atrazine, tetrabromobisphenol A, tetrachlorobenzene, and a polybrominated diphenyl ether (PBDE).
- Anwar, Muhammad,Beller, Matthias,Dastgir, Sarim,Junge, Kathrin,Leonard, David K.,Ryabchuk, Pavel
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- Preparation method of methyl benzoate compound
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A preparation method of a methyl benzoate compound comprises the step that the methyl benzoate compound is prepared by carrying out esterification reaction on a benzoic acid compound and methyl alcohol under the catalysis of dihalogen hydantoin, and the molar ratio of the benzoic acid compound to the dihalogen hydantoin to the methyl alcohol is 1: (0.01-0.4): (2-30). According to the preparation method, the methyl benzoate compound can be efficiently prepared under mild conditions, the operation is safe, no acid waste liquid exists, meanwhile, raw materials are easy to obtain, and the production cost is low.
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Paragraph 0019; 0037-0038
(2021/08/14)
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- Antibacterial and Antiviral Activities of 1,3,4-Oxadiazole Thioether 4H-Chromen-4-one Derivatives
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Various 1,3,4-oxadiazole thioether 4H-chromen-4-one derivatives were conceived. The title compounds demonstrated striking inhibitory effects againstXac,Psa, andXoo. EC50data exhibited that A8 (19.7 μg/mL) had better antibacterial activity againstXoothan myricetin, BT, and TC. Simultaneously, the mechanism of action of A8 had been verified by SEM. The results of anti-tobacco mosaic virus indicated that A9 had the bestin vivoantiviral effect compared with ningnanmycin. From the data of MST, it could be seen that A9 (0.003 ± 0.001 μmol/L) exhibited a strong binding capacity, which was far superior to ningnanmycin (2.726 ± 1.301 μmol/L). This study shows that the 1,3,4-oxadiazole thioether 4H-chromen-4-one derivatives may become agricultural drugs with great potential.
- Cao, Xiao,Liu, Fang,Liu, Liwei,Liu, Tingting,Peng, Feng,Wang, Qifan,Xie, Chengwei,Xue, Wei,Yang, Jinsong
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p. 11085 - 11094
(2021/10/01)
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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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- Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers
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Herein, a new wave of bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in?vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a, 23i, 23j, 23l, and 23n displayed the highest antiproliferative activities against the two cell lines with IC50 values ranging from 6.4 to 19.4 μM. Furthermore, compounds 23a, 23d, 23h, 23i, 23j, 23l, 23 m, and 23n showed the highest VEGFR-2 inhibitory activities with IC50 values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC50 = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).
- Al-Mehizia, Abdulrahman A.,Alanazi, Manal M.,Alanazi, Mohammed M.,Aldawas, Saleh,Alsaif, Nawaf A.,Elkady, Hazem,Elwan, Alaa,Obaidullah, Ahmad J.,Taghour, Mohammed S.
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p. 1093 - 1114
(2021/06/11)
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- Discovery of novel furo[2,3-d]pyrimidin-2-one–1,3,4-oxadiazole hybrid derivatives as dual antiviral and anticancer agents that induce apoptosis
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A new series of furo[2,3-d]pyrimidine–1,3,4-oxadiazole hybrid derivatives were synthesized via an environmentally friendly, multistep synthetic tool and a one-pot Songoashira-heterocyclization protocol using, for the first time, nanostructured palladium pyrophosphate (Na2PdP2O7) as a heterogeneous catalyst. Compounds 9a–c exhibited broad-spectrum activity with low micromolar EC50 values toward wild and mutant varicella-zoster virus (VZV) strains. Compound 9b was up to threefold more potent than the reference drug acyclovir against thymidine kinase-deficient VZV strains. Importantly, derivative 9b was not cytostatic at the maximum tested concentration (CC50 > 100 μM) and had an acceptable selectivity index value of up to 7.8. Moreover, all synthesized 1,3,4-oxadiazole hybrids were evaluated for their cytotoxic activity in four human cancer cell lines: fibrosarcoma (HT-1080), breast (MCF-7 and MDA-MB-231), and lung carcinoma (A549). Data showed that compound 8f exhibits moderate cytotoxicity, with IC50 values ranging from 13.89 to 19.43 μM. Besides, compound 8f induced apoptosis through caspase 3/7 activation, cell death independently of the mitochondrial pathway, and cell cycle arrest in the S phase for HT1080 cells and the G1/M phase for A549 cells. Finally, the molecular docking study confirmed that the anticancer activity of the synthesized compounds is mediated by the activation of caspase 3.
- El Mansouri, Az-eddine,Oubella, Ali,Danoun, Karim,Ahmad, Mehdi,Neyts, Johan,Jochmans, Dirk,Snoeck, Robert,Andrei, Graciela,Morjani, Hamid,Zahouily, Mohamed,Lazrek, Hassan B.
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- Efficient Synthesis of Fluorinated [1,2,4]Triazolo[3,4-b][1,3,4]thiadiazoles
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Abstract: An efficient synthesis of fluorinated [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives has been achievedby cyclocondensation of 5-substituted 4-amino-1,2,4-triazole-3-thiols withfluoro-substituted aromatic acids using phosphoryl chloride as a cyclizingagent. The synthesized compounds were characterized by spectroscopic techniques,including IR, 1H NMR, and mass spectra.
- Dhotre, B. K.,Jagrut, V. B.,Pathan, M. A.,Patharia, M. A.,Raut, S. V.
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p. 1135 - 1140
(2021/09/08)
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- Br?nsted acid-catalyzed chlorination of aromatic carboxylic acids
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The chlorination of aromatic carboxylic acids with SOCl2 has been effectively performed by reacting with a Br?nsted acid as the catalyst. Based on this discovery, an efficient catalytic method that is cheaper than traditional catalytic methods was developed. 20 substrates were chlorinated offering excellent yields in a short reaction time. And the SOCl2/Br?nsted acid system has been used in a larger scale preparative reaction. A dual activation mechanism was proposed to prove the irreplaceable system of SOCl2/Br?nsted acid.
- Yu, Zhiqun,Yao, Hongmiao,Xu, Qilin,Liu, Jiming,Le, Xingmao,Ren, Minna
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supporting information
p. 685 - 689
(2021/04/09)
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- Hydroxyl radical-mediated oxidative cleavage of CC bonds and further esterification reaction by heterogeneous semiconductor photocatalysis
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A hydroxyl radical-mediated aerobic cleavage of alkenes and further sequence esterification reaction for the preparation of carbonyl compounds have been developed by using tubular carbon nitride (TCN) as a general heterogeneous photocatalyst under an oxygen atmosphere with visible light irradiation. This protocol has an excellent substrate scope and gives the desired aldehydes, ketones and esters in moderate to high yields. Importantly, this metal-free procedure employed photogenerated hydroxyl radicals in situ as green oxidation active species, avoiding the present additional initiators. The reaction could be carried out under solar light irradiation and was applicable to large-scale reactions. Furthermore, the recyclable TCN catalyst could be used several times without a significant loss of activities.
- Hong, Mei,Jia, Rui,Miao, Hongyan,Ni, Bangqing,Niu, Tengfei,Wang, Hui
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p. 6591 - 6597
(2021/09/10)
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- 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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- Ultrafine Copper Oxide Particles Dispersed on Nitrogen-Doped Hollow Carbon Nanospheres for Oxidative Esterification of Biomass-Derived 5-Hydroxymethylfurfural
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One-pot synthesis of furan-2,5-dimethylcarboxylate (FDMC) from 5-hydroxymethylfurfural (HMF) is highly demanding for the commercial production of polyethylene furanoate (PEF). Herein, a direct synthesis of FDMC is reported from oxidative esterification of HMF using ultrafine CuO particles dispersed on nitrogen-doped hollow carbon nanospheres (CuO/N?C?HNSs) as a catalyst and tert-butyl hydroperoxide (TBHP) as an oxidizing and methylating reagent. The CuO/N?C?HNSs was prepared through a template protection-sacrifice strategy using SiO2 as a sacrificial template and histidine as the precursor for N and C. N-doping facilitated a strong interaction between the support and copper species, affording formation of CuO nanoparticles of less than 10 nm in size. By virtue of the highly dispersed CuO nanoparticles and a high BET surface area 373 m2/g, the CuO/N?C?HNSsshows excellent catalytic performance in the selective conversion of HMF into FDMC affording 93 % yield of the desired product with a TON value of 49. Furthermore, the oxidative esterification involving SP3C?H bond functionalization is also demonstrated using the same catalyst.
- Gupta, Shyam Sunder R.,Vinu, Ajayan,Kantam, Mannepalli Lakshmi
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p. 259 - 269
(2021/03/01)
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- Scalable On-Demand Production of Purified Diazomethane Suitable for Sensitive Catalytic Reactions
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We have developed a convenient development-scale reactor (0.44 mol/h) to prepare diazomethane from N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in ~80% yield. Diazomethane (CH2N2) made with this reactor is extracted into nitrogen gas from the liquid reaction mixture, effectively removing it from reagents and byproducts that may interfere in subsequent reactions. Vertically oriented tubular reactors were used to produce and consume diazomethane in situ. Key features of this reactor include high productivity and correspondingly low reactor volume (reactor volume/liquid flow rate = 6.5 min) and a commercially available gas/liquid separator equipped with a selectively permeating hydrophilic membrane. The design of the reactor keeps the inventory below 53 mg of CH2N2 during normal operation. The reactor was demonstrated by generating CH2N2 that was used in a connected continuous reactor. We evaluated esterification reactions and a continuous Pd-catalyzed cyclopropanation reaction with the reactor and achieved high conversion with 1.5 and 4.1 equiv of MNTS precursor, respectively.
- Sheeran, Jillian W.,Campbell, Kiersten,Breen, Christopher P.,Hummel, Gerald,Huang, Changfeng,Datta, Anamika,Boyer, Serge H.,Hecker, Scott J.,Bio, Matthew M.,Fang, Yuan-Qing,Ford, David D.,Russell, M. Grace
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supporting information
p. 522 - 528
(2021/02/03)
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- Photoinduced Cross-Coupling of Aryl Iodides with Alkenes
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A protocol for photoinduced cross-coupling of aryl iodides having polar π-functional groups or elongated π-conjugation with alkenes has been developed. The radical cascade mechanism involving generation of aryl radicals via C-I bond homolysis of photoexcited aryl iodides and their subsequent addition to alkenes is proposed. The method enables iodide-selective cross-coupling over other halogen leaving groups with functional group compatibility on both arene and alkene motifs.
- Liu, Yuliang,Li, Haoyu,Chiba, Shunsuke
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p. 427 - 432
(2021/01/26)
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- Syntheses, biological evaluation of some novel substituted benzoic acid derivatives bearing hydrazone as linker
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On the basis of rational drug design fourteen novel compounds having benzoic acid as acidic head,?hydrazone?as?linker?and?substituted?diaryl?sulfanyl/aryl-cyclohexylsulfanyl?as?a?hydrophobic?tail?were synthesized?and?characterized by physicochemical and spectrophotometric (FTIR, Mass, 1HNMR and 13CNMR) analysis. The spectral data were satisfactory with their structures. The?designed compounds were docked against peroxisome proliferated activated receptors (PPARγ) and further evaluated for in vitro PPARγ agonist activity and in vivo hypoglycemic activity in wistar strain of albino rats.?Compound 3k and 3m exhibited potent?anti-diabetic activity without ulcerogenic toxicity and minimum side effects as weight gain. Therefore these compounds would be considered as promising agents for the development of novel antidiabetic agents.
- Mishra, Ganesh Prasad,Sharma, Rajesh,Jain, Mukul,Bandyopadhyay, Debdutta
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p. 5061 - 5078
(2021/08/03)
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- Cobalt single atoms anchored on nitrogen-doped porous carbon as an efficient catalyst for oxidation of silanes
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The oxidation reactions of organic compounds are important transformations for the fine and bulk chemical industry. However, they usually involve the use of noble metal catalysts and suffer from toxic or environmental issues. Here, an efficient, environmentally friendly, and atomically dispersed Co catalyst (Co-N-C) was preparedviaa simple, porous MgO template and etching method using 1,10-phenanthroline as C and N sources, and CoCl2·6H2O as the metal source. The obtained Co-N-C catalyst exhibits excellent catalytic performance for the oxidation of silanes with 97% isolated yield of organosilanol under mild conditions (room temperature, H2O as an oxidant, 1.8 h), and good stability with 95% isolated yield after nine consecutive reactions. The turnover frequency (TOF) is as high as 381 h?1, exceeding those of most non-noble metal catalysts and some noble metal catalysts. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), extended X-ray absorption fine structure (EXAFS), and wavelet transform (WT) spectroscopy corroborate the existence of atomically dispersed Co. The coordination numbers of Co affected by the pyrolysis temperature in Co-N-C-700, Co-N-C-800, and Co-N-C-900 are 4.1, 3.6, and 2.2, respectively. Owing to a higher Co-N3content, Co-N-C-800 shows more outstanding catalytic performance than Co-N-C-700 and Co-N-C-800. Moreover, density functional theory (DFT) calculations reveal that the Co-N3structure exhibits more activity compared with Co-N4and Co-N2, which is because the Co atom in Co-N3was bound with both H atom and Si atom, and it induced the longest Si-H bond.
- Yang, Fan,Liu, Zhihui,Liu, Xiaodong,Feng, Andong,Zhang, Bing,Yang, Wang,Li, Yongfeng
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supporting information
p. 1026 - 1035
(2021/02/09)
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- 1, 3, 4-oxadiazole hydrazide compound as well as preparation method and application thereof
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The invention relates to a 1, 3, 4-oxadiazole hydrazide compound as well as a preparation method and application thereof. The compound has a structure as shown in a general formula (I), according to the invention, the method includes taking a 1, 3, 4-oxadiazole compound as a basis and introducing hydrazide into the system; the compound has a good inhibition effect on plant pathogenic bacteria, fungi and oomycetes, and has a good inhibition effect on pathogenic bacteria such as rice bacterial leaf blight, wheat scab, pepper fusarium wilt, sclerotinia sclerotiorum, colletotrichum gloeosporioides, phytophthora infestans, blueberry root rot and the like.
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Paragraph 0054-0055
(2020/09/02)
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- Synthesis, antifungal and antibacterial activity of calix[4]arene-based 1,3,4-oxadiazole derivatives
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We describe the synthesis of some novel p-tert-butylcalix[4]arene-based (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate derivatives (4a–e). These compounds were synthesized by the reaction of tetra-tert-butyl calix[4]arene (1) with (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a–e) in the presence of potassium carbonate as a weak base and dry acetone as the solvent. All the newly synthesized calix[4]arene derivatives were characterized by elemental analysis and various spectroscopic methods such as FT-IR, 1H NMR,13C NMR, DEPT, and ESI-MS. The synthesized compounds were tested in vitro for their antibacterial and antifungal activities against Escherichia coli and Aspergillus fumigates in comparison with enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections. The synthesized compounds showed different inhibition zones against the tested bacteria and fungi. Compound 4c was found to be most effective against A. fumigates, whereas compound 4e was found to be equally effective against E. coli and A. fumigates.
- Dono Gezelbash, Zahra,Akbari Dilmaghani, Karim
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p. 1446 - 1452
(2020/03/11)
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- Synthesis, biological evaluation of benzothiazole derivatives bearing a 1,3,4-oxadiazole moiety as potential anti-oxidant and anti-inflammatory agents
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Twenty benzothiazole derivatives bearing a 1,3,4-oxadiazole moiety were synthesized and evaluated for their anti-oxidant and anti-inflammatory activities. Among these compounds, 8h and 8l were appeared to have high radical scavenging efficacies as 0.05 ± 0.02 and 0.07 ± 0.03 mmol/L of IC50 values in ABTS+[rad] bioassay, respectively. In anti-inflammatory tests, compound 8h displayed good activity with 57.35% inhibition after intraperitoneal administration, which was more potent than the reference drug (indomethacin). Molecular modeling studies were performed to investigate the binding mode of the representative compound 8h into COX-2 enzyme. In vitro enzyme study implied that compound 8h exerted its anti-inflammatory activity through COX-2 inhibition.
- Bai, Xue-Qian,Cui, Ming-Yue,Li, Chun-Shi,Liang, Cheng-Wu,Song, Ze-Wen,Wang, Hui-Yan,Zhang, Tian-Yi,Zheng, Xian-Jing
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- Modulation of estrogen-related receptors subtype selectivity: Conversion of an ERRβ/γ selective agonist to ERRα/β/γ pan agonists
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Estrogen Related Receptors (ERRs) are key regulators of energy homeostasis and play important role in the etiology of metabolic disorders, skeletal muscle related disorders, and neurodegenerative diseases. Among the three ERR isoforms, ERRα emerged as a potential drug target for metabolic and neurodegenerative diseases. Although ERRβ/γ selective agonist chemical tools have been identified, there are no chemical tools that effectively target ERRα agonism. We successfully engineered high affinity ERRα agonism into a chemical scaffold that displays selective ERRβ/γ agonist activity (GSK4716), providing novel ERRα/β/γ pan agonists that can be used as tools to probe the physiological roles of these nuclear receptors. We identified the structural requirements to enhance selectivity toward ERRα. Molecular modeling shows that our novel modulators have favorable binding modes in the LBP of ERRα and can induce conformational changes where Phe328 that originally occupies the pocket is dislocated to accommodate the ligands in a rather small cavity. The best agonists up-regulated the expression of target genes PGC-1α and PGC-1β, which are necessary to achieve maximal mitochondrial biogenesis. Moreover, they increased the mRNA levels of PDK4, which play an important role in energy homeostasis.
- Avdagic, Amer,Billon, Cyrielle,Burris, Sheryl L.,Burris, Thomas P.,Elagawany, Mohamed,Elgendy, Bahaa,Goher, Shaimaa S.,Hegazy, Lamees,Sanders, Ryan,Shahien, Mohamed,Sitaula, Sadichha
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- Design, synthesis, and biological evaluation of new challenging thalidomide analogs as potential anticancer immunomodulatory agents
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Thalidomide and its analogs are immunomodulatory drugs that inhibit the production of certain inflammatory mediators associated with cancer. In the present work, a new series of thalidomide analogs was designed and synthesized to obtain new effective antitumor immunomodulatory agents. The synthesized compounds were evaluated for their cytotoxic activities against a panel of four cancer cell lines (HepG-2, HCT-116, PC3 and MCF-7). Compounds 33h, 33i, 42f and 42h showed strong potencies against all tested cell lines with IC50 values ranging from 14.63 to 49.90 μM comparable to that of thalidomide (IC50 values ranging from 32.12 to 76.91 μM). The most active compounds were further evaluated for their in vitro immunomodulatory activities via estimation of human tumor necrosis factor alpha (TNF-α), human caspase-8 (CASP8), human vascular endothelial growth factor (VEGF), and nuclear factor kappa-B P65 (NF-κB P65) in HCT-116 cells. Thalidomide was used as a positive control. Compounds 33h and 42f showed a significant reduction in TNF-α. Furthermore, compounds 33i and 42f exhibited significant elevation in CASP8 levels. Compounds 33i and 42f inhibited VEGF. In addition, compound 42f showed significant decrease in levels of NF-κB p65. Moreover, apoptosis and cell cycle tests of the most active compound 42f, were performed. The results indicated that compound 42f significantly induce apoptosis in HCT-116 cells and arrest cell cycle at the G2/M phase.
- El-Zahabi, Mohamed Ayman,Sakr, Helmy,El-Adl, Khaled.,Zayed, Mohamed,Abdelraheem, Adel S.,Eissa, Sally I.,Elkady, Hazem,Eissa, Ibrahim H.
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- C-C Bond Cleavage of Unactivated 2-Acylimidazoles
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2-Acylimidazoles are widely used as post-Transformable carboxylic acid equivalents in chemoselective and enantioselective reactions. Their transformations, however, require pretreatment with highly reactive, toxic methylating reagents to facilitate C-C bond cleavage. Here, we demonstrate that such pretreatment can be avoided and the C-C bond cleaved under neutral conditions without the use of additional reagents or catalysts. The scope of the reaction, including the use of products reported in the literature as substrates, and some mechanistic insights are described.
- Xin, Hai-Long,Pang, Bo,Choi, Jeesoo,Akkad, Walaa,Morimoto, Hiroyuki,Ohshima, Takashi
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p. 11592 - 11606
(2020/10/23)
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- Aerobic Oxidative Cleavage and Esterification of C(OH)–C Bonds
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C(OH)–C bonds are widely distributed in naturally renewable biomass, such as carbohydrates, lignin, and their platform molecules. Selective cleavage and functionalization of C(OH)–C bonds is an attractive strategy in terms of producing value-added chemicals from biomass. However, effective transformation of alcohols into esters by activation of C(OH)–C bonds has not been achieved so far. Herein, for the first time, we report selective cleavage and esterification of C(OH)–C bonds, catalyzed by inexpensive copper salts, using environmentally benign oxygen as the oxidant, to afford methyl esters in excellent yields. A diverse range of phenylethanol derivatives that contain C(OH)–C bonds were effectively converted into methyl benzoates. Detailed analysis revealed that the high efficiency and selectivity resulted mainly from the fact that, in addition to the major esterification reaction, the side products (e.g., olefins and acids) were also transformed in situ into esters in the reaction system. C(OH)–C bonds are widely distributed in naturally renewable biomass. In the context of developing future biorefineries, selective cleavage and functionalization of C(OH)–C bonds are crucial and represent an attractive strategy in terms of producing value-added chemical compounds from biomass resources. In the current manuscript, we report, for the first time, an effective and selective method for the cleavage and esterification of C(OH)–C bonds of alcohols to produce esters, by using environmentally benign O2 as the terminal oxidant and inexpensive commercially available copper salts as catalysts. Furthermore, a detailed mechanistic study revealed that, in addition to the major esterification route, side products (e.g., olefins and acids), which are inevitably generated under oxidative and basic conditions, were also simultaneously converted into esters, thus significantly improving the final yields of target ester products. Native lignin represents the only naturally sustainable aromatic resource. Transformation of native lignin into valuable aromatics would make a great contribution to our planet. We report, for the first time, the effective transformation of alcohols into esters by esterification of C(OH)–C bonds, which offers a new way for the simultaneous degradation and functionalization of lignin. This reaction promotes new explorations for biomass valorization.
- Liu, Mingyang,Zhang, Zhanrong,Yan, Jiang,Liu, Shuaishuai,Liu, Huizhen,Liu, Zhaotie,Wang, Weitao,He, Zhenhong,Han, Buxing
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supporting information
p. 3288 - 3296
(2020/10/20)
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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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- Copper-catalyzed oxidative methyl-esterification of 5-hydroxymethylfurfural using TBHP as an oxidizing and methylating reagent: A new approach for the synthesis of furan-2,5-dimethylcarboxylate
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Catalytic conversion of 5-hydroxymethylfurfural (HMF) into furan-2,5-dimethylcarboxylate (FDMC) is of great significance in the production of polyethylene furanoate (PEF), a renewable biomass-derived polymer that can replace the fossil dependent polyethylene terephthalate (PET). Herein, for the first time, we report the synthesis of FDMC from oxidative methyl-esterification of HMF using tert-butyl hydroperoxide (TBHP) as an oxidizing and methylating reagent catalyzed by mesoporous alumina nanospheres-embedded with CuO nanoparticles (CuO/m-Al2O3). The CuO/m-Al2O3 catalysts with different copper contents were prepared by evaporation-induced self-assembly of a structure-directing agent (Pluronic P-123). The decomposition of P-123 during calcination in air results into the formation of a mesoporous structure with highly dispersed CuO nanoparticles. The as-prepared 6-CuO/m-Al2O3 exhibits excellent catalytic activity towards oxidative methyl-esterification of HMF into FDMC with 92% yield and turnover frequency (TOF) of 0.56 h?1. Furthermore, oxidative methyl-esterification of a range of substrates through SP3 C[sbnd]H bond functionalization has also been demonstrated using the same catalyst.
- Gupta, Shyam Sunder R.,Kantam, Mannepalli Lakshmi,Vinu, Ajayan
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p. 259 - 269
(2020/06/27)
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- Visible-light-induced selective aerobic oxidation of sp3 C-H bonds catalyzed by a heterogeneous AgI/BiVO4 catalyst
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An efficient oxidation of sp3 C-H bonds to esters and ketones has been developed using AgI/BiVO4 as the photocatalyst and O2 as the oxidant in water. Various substrates can be transformed into the desired esters and ketones in moderate to good yields. The synthetic utility of this approach has been demonstrated by gram-level experiments and consecutive oxidation experiments. A plausible mechanism has been proposed.
- Jiang, Li-Ya,Ming, Jing-Jing,Wang, Lian-Yue,Jiang, Yuan-Yuan,Ren, Lan-Hui,Wang, Zi-Cheng,Cheng, Wen-Chen
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supporting information
p. 1156 - 1163
(2020/03/11)
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- Synthesis, characterization, and nonlinear optical properties of some new series of S-(5-aryl-1,3,4-oxadiazol-2-yl) 2-chloroethanethioate derivatives
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In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a–3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, 1 H NMR, 13 C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a–3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from 1011 m2/W order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a–3e) have also been evaluated for their antimicrobial and antifungal activities. The bioactive assay showed that the synthetic compounds displayed variable inhibition zones against tested bacterium Escherichia coli and fungus Aspergillus fumigatus in comparison to enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections.
- Ghezelbash, Zahra Dono,Motiei, Hamideh,Mahmoody, Miri,Dilmaghani, Karim Akbari
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p. 902 - 910
(2019/07/17)
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- Development of novel liver?X?receptor modulators based on a 1,2,4-triazole scaffold
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Liver X Receptor (LXR) agonists have been reported as a potential treatment for atherosclerosis, Alzheimer's disease and hepatitis C virus (HCV) infection. We have designed and synthesized a series of potent compounds based on a 1,2,4-triazole scaffold as novel LXR modulators. In cell-based cotransfection assays these compounds generally functioned as LXR agonists and we observed compounds with selectivity towards LXRα (7-fold) and LXRβ (7-fold) in terms of potency. Assessment of the effects of selected compounds on LXR target gene expression in HepG2 cells revealed that compounds 6a-b and 8a-b behaved as inverse agonists on FASN expression even though they were agonists in the LXRα and LXRβ cotransfection assays. Interestingly, these compounds had no effect on the expression of SREBP-1c confirming a unique LXR modulator pharmacology. Molecular docking studies and evaluation of ADME properties in-silico show that active compounds possess favorable binding modes and ADME profiles. Thus, these compounds may be useful for in vivo characterization of LXR modulators with unique profiles and determination of their potential clinical utility.
- Goher, Shaimaa S.,Griffett, Kristine,Hegazy, Lamees,Elagawany, Mohamed,Arief, Mohamed M.H.,Avdagic, Amer,Banerjee, Subhashis,Burris, Thomas P.,Elgendy, Bahaa
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supporting information
p. 449 - 453
(2019/01/04)
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- 5-Aryl-1,3,4-oxadiazol-2-ylthioalkanoic Acids: A Highly Potent New Class of Inhibitors of Rho/Myocardin-Related Transcription Factor (MRTF)/Serum Response Factor (SRF)-Mediated Gene Transcription as Potential Antifibrotic Agents for Scleroderma
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Through a phenotypic high-throughput screen using a serum response element luciferase promoter, we identified a novel 5-aryl-1,3,4-oxadiazol-2-ylthiopropionic acid lead inhibitor of Rho/myocardin-related transcription factor (MRTF)/serum response factor (SRF)-mediated gene transcription with good potency (IC50 = 180 nM). We were able to rapidly improve the cellular potency by 5 orders of magnitude guided by sharply defined and synergistic SAR. The remarkable potency and depth of the SAR, as well as the relatively low molecular weight of the series, suggests, but does not prove, that binding to the unknown molecular target may be occurring through a covalent mechanism. The series nevertheless has no observable cytotoxicity up to 100 μM. Ensuing pharmacokinetic optimization resulted in the development of two potent and orally bioavailable anti-fibrotic agents that were capable of dose-dependently reducing connective tissue growth factor gene expression in vitro as well as significantly reducing the development of bleomycin-induced dermal fibrosis in mice in vivo.
- Kahl, Dylan J.,Hutchings, Kim M.,Lisabeth, Erika Mathes,Haak, Andrew J.,Leipprandt, Jeffrey R.,Dexheimer, Thomas,Khanna, Dinesh,Tsou, Pei-Suen,Campbell, Phillip L.,Fox, David A.,Wen, Bo,Sun, Duxin,Bailie, Marc,Neubig, Richard R.,Larsen, Scott D.
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p. 4350 - 4369
(2019/05/08)
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- Implementing Hydrogen Atom Transfer (HAT) Catalysis for Rapid and Selective Reductive Photoredox Transformations in Continuous Flow
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The reductive transformation of aryl halides and carbonyl compounds is a key step in many photoredox transformations. By combining a highly reducing organic photocatalyst with a thiol hydrogen atom transfer (HAT) catalyst, we showcase rapid and highly selective reactions of these synthetically important starting materials in continuous flow. The fast reduction of aryl iodides, bromides and chlorides has been demonstrated with residence times in some cases below one minute. Selectivity between mono- and di-dehalogenation could also be achieved in some cases. Aryl ketones, aldehydes and imines were shown to undergo facile pinacol couplings, and the coupling of an aryl chloride with a styrene was also successful.
- Steiner, Alexander,Williams, Jason D.,Rincón, Juan A,de Frutos, Oscar,Mateos, Carlos,Kappe, C. Oliver
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supporting information
p. 5807 - 5811
(2019/08/01)
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- Nickel-catalyzed regioselective C-H halogenation of electron-deficient arenes
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A straightforward Ni(ii)-catalyzed general strategy was developed for the ortho-halogenation of electron-deficient arenes with easily available halogenating reagents N-halosuccinimides (NXS; X = Br, Cl and I). The transformation was highly regioselective and a wide substrate scope and functional group tolerance were observed. This discovery could be of great significance for the selective halogenation of amides, benzoic esters and other substances with guiding groups. Mechanistic investigations were also described.
- Li, Ze-Lin,Wu, Peng-Yu,Cai, Chun
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supporting information
p. 3462 - 3468
(2019/02/25)
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- Method for preparing carboxylic ester by alcohol direct oxidation esterification method
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The invention discloses a method for preparing a carboxylic ester by an alcohol direct oxidation esterification method. The method comprises the following steps: taking an aromatic alcohol compound ora saturated linear aliphatic alcohol as a reaction substrate, taking an Au-Co composite particle carrier as a catalyst, adding a low catalytic amount of alkali, reacting for 0.5-15 h in a methanol solvent at the temperature of 25-150 DEG C in air or oxygen or a mixed atmosphere of the air or the oxygen, and performing aftertreatment to obtain a target product carboxylic ester. According to the preparation method disclosed by the invention, the process steps are reduced, conditions are mild, catalyst consumption is less, atom economy is high, the method is simple to operate, the application range of the substrate is wide, and industrial practicability is achieved.
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-
Paragraph 0052; 0053
(2019/06/30)
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- Pd-Colloids-Catalyzed/Ag2O-Oxidized General and Selective Esterification of Benzylic Alcohols
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Palladium colloids obtained from the degradation of Hermann–Beller palladacycle proved to be an efficient catalytic system in combination with silver oxide as a selective oxidant for the oxidative esterification of differently substituted benzyl alcohols in MeOH as solvent. Excellent reactivity exhibited by the catalytic system also allowed the alcoholic coupling partner to be changed from MeOH to a wide range of alcohols having diverse functionalities. The mildness of the developed protocol also made it possible to employ propargyl alcohol as the coupling partner without any observation of any interference of the terminal alkyne. Selective oxidative coupling of a primary alcoholic functional group over secondary in the case of glycols and glycerols was also made possible using the developed catalyst system. To test the relevancy of Pd/Ag combined catalysis mixed Pd/Ag colloids were synthesized, characterized by TEM, XRD and XPS and applied to oxidative-esterification successfully.
- Sable, Vaibhav,Shah, Jagrut,Sharma, Anuja,Kapdi, Anant R.
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supporting information
p. 2639 - 2647
(2019/07/08)
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- 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane: An efficient and high oxygen content oxidant in various oxidative reactions
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Several oxidative approaches namely thiocyanation of aromatic compounds, epoxidation of alkenes, amidation of aromatic aldehydes, epoxidation of α β-unsaturated ketones, oxidation of sulfides to sulfoxides and sulfones, bayer-villeger reaction, bromination and iodation of aniline and phenol derivatives oxidative esterification, oxidation of pyridines and oxidation of secondary, allylic and benzyllic alcohols were carried out using 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as the potential solid oxidant which can be stored for several months without any loss in its activity. All of the procedures were accomplished via mild reaction conditions and the products were afforded in high yields and short reaction times.
- Khosravi, Kaveh,Naserifar, Shirin
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supporting information
p. 6584 - 6592
(2018/10/05)
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- Study of new synthesized ferrocenyl ionic liquids in oxidative esterification reaction
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In this work, novel ferrocene-based ionic liquids, 1-(ferrocenylbutyl)-4-(3-methylimidazolium) Azide and 1-(ferrocenylbutyl)-4-(3-methylimidazolium) Tetrafluoroborate, were synthesized and utilized in the oxidation esterification reaction of aldehydes in the present of different reagents such as NaN3, (K2CO3 and NCS), (KI and KCN), (I2 and K2CO3), (KMnO4). The results were compared with that of [BMIM][X] (X?Cl, BF4) under the same conditions. As expected, ferrocene-based ionic liquids showed better results; It seems, iron nuclear may play a similar role such as iron catalysts in these novel ionic liquids and can facilitated the oxidation esterification reaction with improve the yield and decrease the reaction time.
- Teimuri-Mofrad, Reza,Rahimpour, Keshvar,Rezaei, Hannaneh,Valizadeh, Hassan,Aghaiepour, Alireza
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p. 1425 - 1435
(2018/04/05)
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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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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- 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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- Selective conversion of primary amides to esters promoted by KHSO4
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Primary amides, either aliphatic or aromatic, are easily converted to the corresponding esters via reflux in lower primary alcohols in the presence of KHSO4. Secondary amides lead to complicated mixtures under analogous conditions, whereastertiary amides were inert. Use of isopropyl alcohol resulted inthe formation of product atslower rate and lower yieldalong withside products, whereas, use of tertiary alcoholsdid not give successful conversion andallyl and benzyl alcohol provided complex mixtures.
- Sattenapally, Narsimha,Sharma, Jhanvi,Hou, Yuqing
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p. 174 - 183
(2018/09/10)
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- Preparation method of aryl diazonium chlorocuprate
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The invention provides a preparation method of aryl diazonium chlorocuprate. Stable salt is formed by aryl diazonium salt and chlorocuprate radicals, the aryl diazonium chlorocuprate is prepared in situ, and a complex is prepared and decomposed by controlling reaction temperature. According to the method, the diazonium salt is prepared by non-aqueous solvents, the aryl diazonium chlorocuprate is then prepared in situ, finally, Sandmeyer is performed by the aid of the difference of stability of the diazonium salt, and recovery and emission reduction functions can be achieved in practical production.
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Paragraph 0050-0054
(2018/05/01)
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- Solvent- and Metal-free Oxidative Esterification of Aromatic Aldehydes Using Urea-2,2-dihydroperoxypropane as a New Solid Oxidant
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Urea-2,2-dihydroperoxypropane as a noble and solid gem-dihydroperoxide derivative was used to transform various aromatic aldehydes to their corresponding benzoate derivatives in the presence of HBr under mild conditions at room temperature in high yields and short reaction times.
- Khosravi, Kaveh,Khalaji, Kobra,Naserifar, Shirin
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p. 303 - 309
(2017/03/27)
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- Direct oxidation of aldehydes to methyl esters with urea hydrogen peroxide and p-toluenesulfonyl chloride
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Combination of urea hydrogen peroxide and p-toluenesulfonyl chloride in methanol was proved to be facile and highly efficient for the oxidative methyl esterification of various aldehydes to the corresponding carboxylic methyl esters.
- Jeong, Deuk Jun,Lee, Su Bin,Lee, Jong Chan
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p. 725 - 728
(2017/12/28)
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- Synthesis, crystal structure, DNA interaction and anticancer evaluation of pyruvic acid derived hydrazone and its transition metal complexes
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A novel tridentate chelating ligand, Ethyl 2-(2-(2-chlorobenzoyl)hydrazono)propanoate and its late transition metal complexes were synthesized, characterized and evaluated for anticancer behavior. The structures were elucidated with the help of elemental analyses, spectral (vibrational, electronic, NMR and mass) and thermo-gravimetric techniques. Single crystal X-ray crystallographic studies of the ligand suggest an orthorhombic lattice structure with Pna21 space group. The interaction of ligand and complexes with DNA (CT-DNA) has been extensively studied using absorption, emission, viscosity and thermal denaturation studies with E. coli DNA. The DNA cleavage ability of ligand and metal complexes was tested using plasmid pBR322 DNA by gel electrophoresis method. The ligand and its copper complex have been evaluated for their in vitro anticancer activity against human cancer cells of different origin such as KB (Oral), A431 (Skin), Mia-Pa-Ca (Pancreases), K-549 (Lung), K-562 (Leukemia), MCF-7 (Breast) and VERO by MTT assay and the apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining method. The studies suggest that ligand and copper complex exhibit significant cytotoxic activity on KB, MCF-7, A-431, Mia-Pa-Ca-2 an d A-549 cell lines compared to K-562 and VERO cell lines.
- Hegde, Divya,Dodamani, Suneel,Kumbar, Vijay,Jalalpure, Sunil,Gudasi, Kalagouda B.
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- Design, synthesis, and negative inotropic evaluation of 4-phenyl-1H-1,2,4-triazol-5(4H)-one derivatives containing triazole or piperazine moieties
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In this study, four novel series of 4-phenyl-1H-1,2,4-triazol-5(4H)-one derivatives containing triazole or piperazine moieties were designed, synthesized, and evaluated for negative inotropic activity by measuring the left atrium stroke volume in isolated rabbit heart preparations. Almost all of the compounds showed an ability to moderate the cardiac workload by decreasing the heart rate and contractility. Among them, 7h was found to be the most potent with a change in stroke volume of ?48.22?±?0.36% at a concentration of 3?×?10?5?mol/L (metoprolol: ?9.74?±?0.14%). The cytotoxicity of these compounds was evaluated using the human cervical cancer cell line HeLa, the liver cancer cell line Hep3B, and the human normal hepatic cell line LO2. A preliminary study of the mechanism of action for the compound 7h on the regulation of atrial dynamics with ATP-sensitive K+ channel and L-type Ca2+ channel blockers glibenclamide and nifedipine was performed in the isolated perfused beating rabbit atria.
- Wei, Zhi-Yu,Cui, Bai-Ri,Cui, Xun,Wu, Yan-Ling,Fu, Yang,Liu, Li-Ping,Piao, Hu-Ri
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- Iron(III)/TEMPO-Catalyzed Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles by Oxidative Cyclization under Mild Conditions
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A simple and efficient cationic Fe(III)/TEMPO-catalyzed oxidative cyclization of aroyl hydrazones has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazole derivatives. The reaction offers a broad scope, good functional-group tolerance, and high yields under mild conditions in the presence of O 2.
- Zhang, Guofu,Yu, Yidong,Zhao, Yiyong,Xie, Xiaoqiang,Ding, Chengrong
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supporting information
p. 1373 - 1377
(2017/06/27)
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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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- N-Doped Sub-3 nm Co Nanoparticles as Highly Efficient and Durable Aerobic Oxidative Coupling Catalysts
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A nano-coating associated with sulfuric acid leaching protocol was developed to prepare N-doped sub-3 nm Co-based nanoparticle catalyst (Co?N/C) using melamine–formaldehyde resin as the N-containing precursor, active carbon as the support, and Co(NO3)2 as the Co-containing precursor. By thermal treatment under nitrogen atmosphere at 800 °C and leached with sulfuric acid solution, a stable and highly dispersive Co?N coordination structure was uniformly dispersed on the formed Co?N/C catalyst with a Co loading of 0.47 wt % and Co nanoparticle size of 2.55 nm. The Co?N/C catalyst was characterized with XRD, XPS, Raman, SEM, TEM, ICP, and elemental analysis. The Co?N/C catalyst showed extremely high catalytic efficiency with a TON of 257 for the aerobic oxidative coupling of aldehydes with methanol to directly synthesize methyl esters with molecular oxygen as the final oxidant. The Co?N/C catalyst also showed broad substrate range and stable recyclability. After recycling for 7 times, no obvious deactivation was detected. It was confirmed that the sub-3 nm Co?N coordination structure formed between metallic Co nanoparticles and pyridinic nitrogen doping into graphitic layers functions as the active site to activate molecular oxygen for the β-H elimination from generated hemiacetal intermediates to produce methyl esters. The nano-coating associated with acid leaching protocol provides a novel strategy to prepare highly efficient non-precious metal-based catalysts.
- Han, Junxing,Gu, Feifei,Li, Yuchao
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p. 2594 - 2601
(2016/09/28)
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- A simple, one-pot oxidative esterification of aryl aldehydes through dialkyl acetal using hydrogen peroxide
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A simple and an efficient one-pot procedure has been developed to synthesize various aryl carboxylic esters directly from aryl aldehydes using hydrogen peroxide without any catalyst. The reaction proceeds smoothly at room temperature. A preliminary investigation suggests the formation of dialkyl acetal as an intermediate during the reaction sequence.
- Devarajan,Vijayakumar,Ramalingam,Vijayaraghavan
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p. 5849 - 5858
(2016/06/01)
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