- Pyrophosphate selective fluorescent chemosensors: Cascade recognition of nuclear stain mimicking DAPI
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A new zinc(ii) complex with a condensed hydroxynaphthyl pyridine (SPHN) as the coordinated ligand has been synthesized for the selective recognition of pyrophosphate (PPi) over other anions including phosphate in a mixed aqueous solution. The fluorescence enhancement of SPHN in association with Zn 2+ ions is quenched in the presence of intracellular pyrophosphate. This phenomenon is utilized in the construction of a logic gate. The binding of SPHN with Zn2+ and its displacement by PPi have been established by photophysical investigation and supported by the DFT level of studies. The development of blue fluorescence in the {SPNH-Zn} complex upon binding of zinc with SPHN is shown to be useful as a nucleus marker in a cell similar to the commercially available staining compound, DAPI (diamino-2-phenylindole). This journal is the Partner Organisations 2014.
- Goswami, Shyamaprosad,Das, Avijit Kumar,Pakhira, Bholanath,Basu Roy, Sohini,Maity, Anup Kumar,Saha, Partha,Sarkar, Sabyasachi
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- FRET based selective and ratiometric 'naked-eye' detection of CN - in aqueous solution on fluorescein-Zn-naphthalene ensemble platform
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We have developed a FRET-based ratiometric fluorescent probe for the detection of CN- using a fluorescein-Zn-naphthalene ensemble (NFH·Zn2+). The sensing mechanism was ascribed by displacement approach. The chemosensor exhibits high selectivity and sensibility for CN -. The speculation was supported by fluorescence emission spectra, UV-vis spectrum, 1H NMR titration experiments, and mass spectra. The interconversion of probe NFH and NFH·Zn2+ via the complexation/decomplexation by the modulation of Zn2+/CN- mimics INHIBIT gate. In addition, it also shows an excellent performance in 'dip stick' method.
- Goswami, Shyamaprosad,Paul, Sima,Manna, Abhishek
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- Rapid detection of hydrazine in a naphthol-fused chromenyl loop and its effectiveness in human lung cancer cells: Tuning remarkable selectivity via the reaction altered pathway supported by theoretical studies
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Our designed and synthesized chemosensor naphthalene based chromenyl derivative (NAC) [1-(3-hydroxy-3 methyl-3H-benzo[f]chromen-2-yl) ethanone] has been used for fast (2H4 by a new way via the chromenyl ring opening followed by the pyrazole ring formation giving a strong blue fluorescence. The DFT study and the real application in different water samples along with the dipstick method in low cost devices have also been performed here. Human lung cancer cells (NCI-H460) have been used for hydrazinolysis of the NAC in vivo system for detection by the appearance of blue fluorescence and also for the MTT assay showing its remarkable cancer sensitivity. This journal is
- Goswami, Shyamaprosad,Das, Avijit Kumar,Saha, Urmila,Maity, Sibaprasad,Khanra, Kalyani,Bhattacharyya, Nandan
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- Recognition of Mg2+ and Zn2+ based on a naphthalene-based fluorescent probe by regulating solvents
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In this study, a naphthalene schiff-base which serves as a dual analyte chemosensor and quantifies Mg2+ and Zn2+ has been synthesized. The sensor shows "off-on" fluorescent response toward Mg2+ in acetonitrile while the detection of the sensor could be switched for Zn2+ by regulating solvents from acetonitrile to a mixture of ethanol-water (v/v, 4:1). Both of the sensing mechanisms are attributed to the formation of 1:1 ligand-metal complexes which inhibit photo-induced electron transfer (PET) process. More importantly, the reversibility of the recognition processes of HL is performed by adding a bonding agent Na2EDTA.
- Qin, Jing-Can,Yang, Zheng-Yin,Wang, Guan-Qun
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- Synthesis of 2-hydroxy-1-naphthaldehyde under conditions of heterogeneous catalysis
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A procedure was developed for synthesis of 2-hydroxy-1-naphthaldehyde by Reimer-Tiemann fluorination of 2-naphthol under conditions of heterogeneous catalysis.
- Kalechits,Osinovskii,Matveenko,Ol'khovik
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- Relay recognition of F- and a nerve-agent mimic diethyl cyano-phosphonate in mixed aqueous media: Discrimination of diethyl cyanophosphonate and diethyl chlorophosphate by cyclization induced fluorescence enhancement
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Anion to nerve agent simulant detection by relay recognition has been designed and realized for the first time with sequence specificity (F- → DCNP) via a fluorescence "off-on-on" mechanism. The discrimination of DCNP and DCP via a CIFE (cyclization induced fluorescence enhancement) mechanism has also been demonstrated here. Test strips based on the sensors with F- and DCNP are fabricated, which can act as convenient and efficient nerve agent and F- test kits. The origin of the sequence specificity of different fluorescence recognition was revealed through single X-ray crystal and NMR analysis.
- Das, Avijit Kumar,Goswami, Shyamaprosad,Quah, Ching Kheng,Fun, Hoong-Kun
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- Single chemosensor for highly selective colorimetric and fluorometric dual sensing of Cu(II) as well as 'NIRF' to acetate ion
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A novel fluorescent probe for the copper(II) ion in mixed aqueous media, based on fluorescence quenching mechanism with noticeable color change from light to dark yellow, was designed and synthesized. It also exhibited high selectivity for acetate in acetonitrile over other common anions in the near infrared region (NIR) accompanied with exciting color changes from light yellow to pink. Hence sensor 1 ascertains its dual chemosensing ability toward Cu(II) and acetate ions as evidenced by competitive experiments.
- Goswami, Shyamaprosad,Maity, Sibaprasad,Das, Avijit Kumar,Maity, Annada C.
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- Novel strategy of constructing fluorescent probe for MAO-B via cascade reaction and its application in imaging MAO-B in human astrocyte
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To detect monoamine oxidase B (MAO-B), the level of which is one of the most important indicators of neurodegenerative diseases such as Parkinson's disease, a new type of cascade reaction based on the formation of coumarin was applied in this research. After the reaction with MAO-B, the protecting group of hydroxyl group in probes (DEAN-MA and DEAB-MA) was removed, and the fluorescence intensity significantly increased (λem = 456 nm) as the structure of coumarin was formed subsequently. The probes showed excellent sensitivity and selectivity to MAO-B. The detection limit of DEAN-MA and DEAB-MA were 0.6 ng/mL and 0.2 ng/mL, respectively. We succeeded in detecting MAO-B in vitro and imaging it in human astrocyte (U87).
- Qin, Huihuan,Li, Lingling,Li, Kun,Xiaoqi, Yu
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- Nanoarchitecture self-assembly and photochromic studies of 2,2-diarylnaphthopyrans
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The synthesis and photochromic properties of novel 2,2-diarylnaphthopyrans were described. Significantly, the nanostructured architecture through two-component self-assembly of a photochromic naphthopyran and an asymmetric biphenyl was determined by X-ray diffraction. The structure motifs of nanocavities were formed by Cl?O interactions and Ar-H?Cl hydrogen bonds among the photochromic naphthopyran molecules. It was further shown by TEM that the dimensions of cavity structures were up to nanometer level, which provides the potential to capture useful nanoscale entities and control photochromism in organic materials.
- Tan, Ting-Feng,Han, Jie,Pang, Mei-Li,Fu, Yi-Fang,Ma, Hong,Ma, Yu-Xin,Meng, Ji-Ben
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- Hydrazinopyrimidine derived novel Al3+ chemosensor: Molecular logic gate and biological applications
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Cost-effective and highly sensitive biocompatible probes for the detection of Al3+ have tremendously important practical applications. Herein, we report for the first time, the hydrazinopyrimidine based Al3+ chemosensor L (1-[(4,6-dimethyl-pyrimidin-2-yl)-hydrazonomethyl]-naphthalen-2-ol) prepared by the condensation of 2-hydroxy-1-naphthaldehyde and 4,6-dimethyl-2-hydrazino-pyrimidine. Our as-synthesized chemosensor L (Φ = 0.0066) shows ~15 fold fluorescence enhancement in the presence of Al3+ (Φ = 0.0955, Ka = 1.9 × 104 M-1) via chelation enhanced fluorescence (CHEF), excited state intramolecular proton transfer (ESIPT), and inhibited photo-induced electron transfer (PET) phenomena. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 2.78 μM and 9.27 μM, respectively. Furthermore, for the first time, a hydrazino pyrimidine based 'INHIBIT' molecular logic gate for Al3+ was successfully developed using the fluorescence properties of L. The experimental sensing mechanisms of L for Al3+ were corroborated by theoretical calculations. Biocompatibility and good water-solubility properties of a pyrimidine moiety of L inspired us to investigate Al3+ imaging in human embryonic kidney cell lines, HEK293, and the results for practical applications are highly promising.
- Das, Bhriguram,Dey, Satyajit,Maiti, Guru Prasad,Bhattacharjee, Ankita,Dhara, Anamika,Jana, Atanu
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- A rhodamine derivative as a highly sensitive chemosensor for iron(iii)
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A novel rhodamine-based fluorescent probe P1 was synthesized for the optical detection of Fe3+. Compared with other commonly coexisting metal ions in aqueous system, it exhibited high sensitivity and selectivity for Fe3+. The detection limit was only 0.1 μM with fluorescence experiment. The rapid enhancement of fluorescence intensity on the addition of Fe3+provided a good method for the detection for Fe3+. The color change was visible and distinct, so it could be used for naked-eye detection. Furthermore, the fluorescent probe was proved effective when used for detecting Fe3+in living cells and zebrafish. This showed its values in biological aspects.
- Wu, Kaitian,Xiao, Hongde,Wang, Lele,Yin, Gui,Quan, Yiwu,Wang, Ruiyong
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- Cell compatible fluorescent chemosensor for Hg2+ with high sensitivity and selectivity based on the Rhodamine fluorophore
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An easily prepared "turn-on"-type fluorescent chemosensor for mercury based on Rhodamine-B, which exhibits high sensitivity and selectivity over other metal ions in aqueous systems, was obtained. The distinctive wavelengths in the UV/ Vis absorption range can sense Hg2+, Cu 2+, and Fe3+ separately. Furthermore, this "turn-on"-type fluorescent sensor, upon the addition of Hg 2+ over other competitive species, was successfully applied to bioimaging in yeast and HeLa cells. The potential of these types of chemosensors for use in environmental and biological systems is great.
- Jiang, Li,Wang, Ling,Zhang, Bo,Yin, Gui,Wang, Rui-Yong
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- An OFF–ON–OFF type fluorescent probe based on a naphthalene derivative for Al3+ and F? ions and its biological application
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A novel fluorescent probe-based naphthalene Schiff, 1-(C2-glucosyl-ylimino-methyl)-naphthalene-2-ol (L) was synthesized by coupling d-glucosamine hydrochloride with 2-hydroxy-1-naphthaldehyde. It exhibited excellent selectivity and highly sensitivity for Al3+ in ethanol with a strong fluorescence response, while other common metal ions such as Pb2+, Mg2+, Cu2+, Co2+, Ni2+, Cd2+, Fe2+, Mn2+, Hg2+, Li+, Na+, K+, Fe3+, Cr3+, Zn2+, Ag+, Ba2+ and Ca2+ did not cause the same fluorescence response. The probe selectively bound Al3+ with a binding constant (Ka) of 5.748?×?103?M?1 and a lowest detection limit (LOD) of 4.08?nM. Moreover, the study found that the fluorescence of the L???Al3+ complex could be quenched after addition of F? in the same medium, while other anions, including Cl?, Br?, I?, NO2 ?, NO3 ?, ClO4 ?, CO3 2?, HCO3 ?, SO4 2?, HSO4 ?, CH3COO?, PO4 3?, HPO4 2?, S2? and S2O3 2? had nearly no influence on probe behaviour. Binding of the [L???Al3+] complex to a F? anion was established by different fluorescence titration studies, with a detection limit of 3.2?nM in ethanol. The fluorescent probe was also successfully applied in the imaging detection of Al3+ and F? in living cells.
- Ren, Yanpeng,Han, Juan,Wang, Yun,Tang, Xu,Wang, Lei,Ni, Liang
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- Phosphine-catalyzed sequential (2+3)/(2+4) annulation of γ-vinyl allenoates: Access to the synthesis of chromeno[4,3-: B] pyrroles
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A phosphine-catalyzed cascade (2+3)/(2+4) cyclization reaction of γ-vinyl allenoates with aldimine esters has been developed to provide a series of chromeno[4,3-b]pyrrole derivatives that contain three contiguous stereogenic centers. The method gives a good yield, excellent chemoselectivity and diastereoselectivity under mild conditions.
- Huang, You,Li, Xiaohu
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supporting information
p. 9934 - 9937
(2021/10/12)
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- Molecular iodine mediated oxidative cleavage of the C-N bond of aryl and heteroaryl (dimethylamino)methyl groups into aldehydes
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The oxidative cleavage of the C-N bond of aryl and heteroaryl (dimethylamino)methyl groups is achieved by employing molecular iodine as a mild oxidizing agent under ambient conditions in the presence of a mild base. The important reaction of C3 formylation of free NH and substituted indoles containing various substituents is accomplished from the corresponding Mannich bases. This methodology can also be extended for the synthesis of aryl and other heteroaryl aldehydes and ketones. Furthermore, the usefulness of the method is successfully demonstrated on a gram scale.
- Mandrekar, Ketan S.,Tilve, Santosh G.
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supporting information
p. 4152 - 4155
(2021/03/15)
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- Cu/Ag mediated peroxide-free synthesis of benzoylated naphthol derivatives
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A peroxide-free methodology was developed for the synthesis of benzoylated naphthol/phenol derivatives through oxidative deamination reaction performed under aerobic reaction conditions. A synergistic combination of Cu(OTf)2 and Ag2O was used to convert the aminonaphthols and aminophenols to the corresponding benzoylated derivatives. The definite role of atmospheric oxygen to assist the reaction was proved by performing the reaction in the argon atmosphere.
- Prasanna Kumari, Subramaniyan,Suresh, Pavithira,Muthukumar, Vijayashree,Selva Ganesan, Subramaniapillai
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- Controlling Stereoselectivity in Tribromide Mediated Oxidative Dearomatisations – Synthesis of Selective Spirofurano-naphthalones
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A series of ammonium tribromides were screened for exploring the role of ammonium counterpart attached to tribromides on generation of stereoselective spiro-furans via oxidative dearomatisation of naphthols. The proposition enlightens a suitable combination of the ammonium tribromide and solvent employed, deliver the best achieved diastereoselectivities. This in turn, has also envisioned the mechanistic aspects related to this category of reactions. The mentioned dearomative spiro-furano naphthalones has also been successfully achieved on a large-scale.
- Sarkar, Debayan,Kuila, Puspendu,Sood, Devashish
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supporting information
p. 5894 - 5904
(2019/08/26)
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- Syntheses, spectroscopy, electrochemistry, EPR, PXRD-structure and DFT/TD-DFT of bis[2-oxo-1-naphthaldehydato-κO,O’]copper(II)
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Reaction of N-2-(R-pyridyl)-2-hydroxy-1-naphthaldimine {R = H (HL1), 4-CH3 (HL2) and 6-CH3 (HL3)} with copper(II) nitrate provides the new complex of bis[2-oxo-1-naphthaldehydato-κO,O’]copper(II) (1) via in-situ hydrolysis of the Schiff base back to 2-hydroxy-1-naphthaldehyde (HL′). Elemental analyses reveal that there are no nitrogen atoms in the complex. X-ray diffraction (PXRD) data indicate that the complex is monoclinic with space group P21/a and Z = 2 and that the ligand acts as bidentate through O?O-chelate system forming a bis-complex with O2O2-coordination sphere around the copper(II) ion. Electrochemical results show two quasi-reversible one electron charge transfer processes attributed to [Cu(L′)2]2?/[Cu(L′)2]? and [Cu(L′)2]?/[Cu(L′)2] (L’ = deprotonated aldehyde) couples in acetonitrile. The magnetic data confirm the paramagnetic property of the complex with one unpaired electron in the metallic centre. The results suggest that the complex assumes a geometry between tetrahedral and square-planar supported by DFT calculations. Thermal analysis shows an irreversible phase transformation from solid to isotropic liquid phase. EPR spectrum in chloroform exhibits an isotropic pattern with four lines due to nuclear hyperfine splitting from the copper(II) ion with spin 3/2. The structural analyses, electrochemical and paramagnetic properties of these complexes explore greater interests for their use in the supramolecular chemistry.
- Enamullah, Mohammed,Joy, Baitul Alif,Islam, Mohammad Khairul
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- Organosuperbase dendron manganese complex grafted on magnetic nanoparticles; heterogeneous catalyst for green and selective oxidation of ethylbenzene, cyclohexene and oximes by molecular oxygen
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Magnetic Fe3O4 nanoparticles as a support were modified with an amino-terminated organosilicon and cyanoric choloride ligands. The novel manganese complex was grafted on modified magnetic support (Mn(II)-Met@MMNPs). The nanocatalyst structure, particle size, morphology and surface properties was well characterized by elemental analysis, ICP-AES, AAS, EDS, FT-IR, SEM, TEM, DLS, VSM, TGA, XRD and XPS. In order to develop an effective heterogeneous nanocatalyst for eco-friendly aerobic, highly active and selective catalytic reactions, synthesized nanocatalyst was applied in oxidation of various organic compounds. The catalytic performance of the manganese nanocatalyst in the aerobic oxidation of ethylbenzene (EB), cyclohexene (CYHE) and various aldoximes and ketoxime were studied. Selective aerobic oxidation of EB and CYHE and various oximes were catalyzed by the Mn-nanocatalyst using N-hydroxyphthalimide (NHPI) with molecular oxygen as the green oxidant without the need of any reducing agent, and respectively the acetophenone (AcPO) as a benzylic product, 2-cyclohexene-1-one (CYHE[dbnd]O) as an allylic product and corresponding carbonyl compounds were obtained. The oxidation process has been optimized for Mn-nanocatalyst by considering the effect of different parameters such as the ratio and amount of Mn-nanocatalyst/NHPI, reaction time and solvent for achieving maximum conversion and selectivity to products. Due to their significant low cost, informal preparation, easy magnetically separation from reaction mixture, excellent catalytic performance, simple recovery and reusability without any metal leaching, the Mn-nanocatalyst has huge application prospect in selective and green oxidation process.
- Faraji, Ali Reza,Ashouri, Fatemeh,Hekmatian, Zahra,Heydari, Somayyeh,Mosazadeh, Sima
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- Structure-Guided Synthesis and Mechanistic Studies Reveal Sweetspots on Naphthyl Salicyl Hydrazone Scaffold as Non-Nucleosidic Competitive, Reversible Inhibitors of Human Ribonucleotide Reductase
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Ribonucleotide reductase (RR), an established cancer target, is usually inhibited by antimetabolites, which display multiple cross-reactive effects. Recently, we discovered a naphthyl salicyl acyl hydrazone-based inhibitor (NSAH or E-3a) of human RR (hRR) binding at the catalytic site (C-site) and inhibiting hRR reversibly. We herein report the synthesis and biochemical characterization of 25 distinct analogs. We designed each analog through docking to the C-site of hRR based on our 2.7 ? X-ray crystal structure (PDB ID: 5TUS). Broad tolerance to minor structural variations preserving inhibitory potency is observed. E-3f (82% yield) displayed an in vitro IC50 of 5.3 ± 1.8 μM against hRR, making it the most potent in this series. Kinetic assays reveal that E-3a, E-3c, E-3t, and E-3w bind and inhibit hRR through a reversible and competitive mode. Target selectivity toward the R1 subunit of hRR is established, providing a novel way of inhibition of this crucial enzyme.
- Huff, Sarah E.,Mohammed, Faiz Ahmad,Yang, Mu,Agrawal, Prashansa,Pink, John,Harris, Michael E.,Dealwis, Chris G.,Viswanathan, Rajesh
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supporting information
p. 666 - 680
(2018/02/16)
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- Discovery of boron-containing compounds as Aβ aggregation inhibitors and antioxidants for the treatment of Alzheimer's disease
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A novel series of boron-containing compounds were designed, synthesized and evaluated as multi-target-directed ligands against Alzheimer's disease. The biological activity results demonstrated that these compounds possessed a significant ability to inhibit self-induced Aβ aggregation (20.5-82.8%, 20 μM) and to act as potential antioxidants (oxygen radical absorbance capacity assay using fluorescein (ORAC-FL) values of 2.70-5.87). In particular, compound 17h is a potential lead compound for AD therapy (IC50 = 3.41 μM for self-induced Aβ aggregation; ORAC-FL value = 4.55). Compound 17h also functions as a metal chelator. These results indicated that boron-containing compounds could be new structural scaffolds for the treatment of AD.
- Lu, Chuan-Jun,Hu, Jinhui,Wang, Zechen,Xie, Shishun,Pan, Tingting,Huang, Ling,Li, Xingshu
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p. 1862 - 1870
(2018/11/24)
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- Efficient microwave-assisted regioselective one pot direct: Ortho -formylation of phenol derivatives in the presence of nanocrystalline MgO as a solid base catalyst under solvent-free conditions
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In this research, at first nanocrystalline MgO was prepared and then the solvent-free reactions of phenol derivatives with paraformaldehyde in the presence of the obtained nanocrystalline MgO as a new catalyst under microwave irradiation were investigated. In this reaction, ortho-hydroxyaromatic aldehydes were yielded as products. This method seems to be comparable with other reported methods due to its high yield and regioselectivity. The significant features of this method are short reaction times, high yields, and easy and quick isolation of the products.
- Naeimi, Hossein,Zakerzadeh, Elham
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p. 4590 - 4595
(2018/03/21)
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- Atropoenantioselective redox-neutral amination of biaryl compounds through borrowing hydrogen and dynamic kinetic resolution
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We report herein a novel atropoenantioselective redox-neutral amination of biaryl compounds triggered by a cascade of borrowing hydrogen and dynamic kinetic resolution under the cooperative catalysis of a chiral iridium complex and an achiral Br?nsted acid. This protocol features broad substrate scope and good functional-group tolerance, and allows the rapid assembly of axially chiral biaryl compounds in good to high yields and with high to excellent enantioselectivity.
- Zhang, Jianwei,Wang, Jian
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supporting information
p. 465 - 469
(2017/12/15)
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- Atropoenantioselective Redox-Neutral Amination of Biaryl Compounds through Borrowing Hydrogen and Dynamic Kinetic Resolution
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We report herein a novel atropoenantioselective redox-neutral amination of biaryl compounds triggered by a cascade of borrowing hydrogen and dynamic kinetic resolution under the cooperative catalysis of a chiral iridium complex and an achiral Br?nsted acid. This protocol features broad substrate scope and good functional-group tolerance, and allows the rapid assembly of axially chiral biaryl compounds in good to high yields and with high to excellent enantioselectivity.
- Zhang, Jianwei,Wang, Jian
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supporting information
p. 465 - 469
(2018/02/21)
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- Ruthenium-Catalyzed Atropoenantioselective Synthesis of Axial Biaryls via Reductive Amination and Dynamic Kinetic Resolution
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The unprecedented ruthenium-catalyzed atropoenantioselective reductive amination of aldehydes with alkylamines via a cascade transfer hydrogenation and dynamic kinetic resolution strategy is described. This protocol features broad substrate scope and good functional group tolerance and allows the rapid assembly of axially chiral biaryls in good to high yields with high to excellent enantioselectivities. In addition, such structural motifs may have potential applications in enantioselective catalysis as chiral ligands or catalysts.
- Guo, Donghui,Zhang, Jianwei,Zhang, Bei,Wang, Jian
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supporting information
p. 6284 - 6288
(2018/10/05)
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- Naphthalene-derived Al3+-selective fluorescent chemosensor based on PET and ESIPT in aqueous solution
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A simple fluorescent chemosensor HL based on naphthalene with high selectivity and sensitivity towards Al3+ over other commonly coexisting metal cations in fully aqueous solution to enhance the potential applications of the fluorescent chemosensor was developed. HL exhibited a significant fluorescence enhancement at 475 nm in the presence of Al3+ over other competitive metal ions with a low detection limit of 0.43 μM due to the inhibition of the photo induced electron transfer (PET) and the excited-state intramolecular proton transfer (ESIPT). The 1:1 binding stoichiometry between HL and Al3+ was corroborated by the Job plot and the ESI-MS spectrum. Importantly, the reversible recognition process of HL to Al3+ will make HL could be used circularly and repeatedly in practical applications by addition of Na2EDTA. In addition, the binding behavior and sensing mechanism of HL to Al3+ were illustrated in detail by the 1H NMR titration experiment.
- Yue, Xiao-li,Wang, Zhao-qing,Li, Chao-rui,Yang, Zheng-yin
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p. 4532 - 4537
(2017/11/10)
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- Synthesis of Two Coumarin-Derived Schiff Bases and Investigation of theirs Selectivity for Zn2+
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In this study, the coumarin-derived schiff bases (HL1 and HL2) have been designed and synthesized. Upon the addition of Zn2+, both of them show significant fluorescence enhancement owing to inhibits PET and ESIPT process respectively. However, the receptor HL2 response toward Cd2+, Mg2+, Ba2+, Ca2+ besides Zn2+ and exhibits fluorescence enhancement but not enough to detection of the concentration levels of Zn2+.
- Fan, Long
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p. 1331 - 1337
(2017/06/19)
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- Three-Component Aminoalkylations Yielding Dihydronaphthoxazine-Based Sirtuin Inhibitors: Scaffold Modification and Exploration of Space for Polar Side-Chains
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Nonpolar derivatives of heterocyclic aromatic screening hits like the non-selective sirtuin inhibitor splitomicin tend to be poorly soluble in biological fluids. Unlike sp3-rich natural products, flat aromatic compounds are prone to stacking and often difficult to optimize into leads with activity in cellular systems. The aim of this work was to identify anchor points for the introduction of sp3-rich fragments with polar functional groups into the newly discovered active (IC50 = 5 μM) but nonpolar scaffold 1,2-dihydro-3H-naphth[1,2-e][1,3]oxazine-3-thione by a molecular modeling approach. Docking studies were conducted with structural data from crystallized human SIRT2 enzyme. Subsequent evaluation of the in silico hypotheses through synthesis and biological evaluation of the designed structures was accomplished with the aim to discover new SIRT2 inhibitors with improved aqueous solubility. Derivatives of 8-bromo-1,2-dihydro-3H-naphth[1,2-e][1,3]oxazine-3-thione N-alkylated with a hydrophilic morpholino-alkyl chain at the thiocarbamate group intended for binding in the acetyl-lysine pocket of the enzyme appeared to be promising. Both the sulfur of the thiocarbamate and the bromo substituent were assumed to result in favorable hydrophobic interactions and the basic morpholino-nitrogen was predicted to build a hydrogen bond with the backbone Ile196. While the brominated scaffold showed moderately improved activity (IC50 = 1.8 μM), none of the new compounds displayed submicromolar activity. Synthesis and characterization of the new compounds are reported and the possible reasons for the outcome are discussed.
- Vojacek, Steffen,Beese, Katja,Alhalabi, Zayan,Swyter, S?ren,Bodtke, Anja,Schulzke, Carola,Jung, Manfred,Sippl, Wolfgang,Link, Andreas
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- Effect of some transition complexes on bacteria and fungi causes gastroenteritis in humans
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This study concerned with the synthesis and characterization of some complexes of the ligand. All the complexes are non-electrolytes place, instead crystalline solid compounds insoluble in water, but soluble in organic solvents the negatively charge biden
- Al-Shammaa, Nawal M.J.,Al-Nuaimi, Hanan A.S.
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p. 2591 - 2598
(2017/11/16)
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- METHOD OF MODULATING RIBONUCLEOTIDE REDUCTASE
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A method of modulating ribonucleotide reductase activity in a neoplastic cell includes administering to the cell an amount of a ribonucleotide reductase modulator (RRmod), the amount being effective to inhibit neoplastic cell growth.
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Paragraph 00175
(2017/07/05)
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- Copper catalyzed oxidative deamination of Betti bases: An efficient approach for benzoylation/formylation of naphthols and phenols
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An efficient route for benzoylation or formylation of naphthols/phenols is developed via oxidative deamination of Betti bases. A copper salt catalyst with TBHP as an oxidant is used. Water is used as a reagent as well as solvent. The reaction proceeds through a regioselective radical pathway. Most importantly, the position of acylation is unambiguous. The method is also applicable to non-hydroxy substrates.
- Deb, Mohit L.,Pegu, Choitanya Dev,Borpatra, Paran J.,Baruah, Pranjal K.
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p. 40552 - 40559
(2016/05/24)
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- Novel use of BiOCl as an efficient and selective reagent for cleavage of 2,4-dinitrophenylhydrazones to carbonyl compounds
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A novel use of bismuth oxychloride (BiOCl) as an efficient and selective catalyst for the clean cleavage of 2,4-dinitrophenylhydrazones under mild conditions is reported. The reactions proceed very smoothly, and the yields are good to excellent. Over oxidation of aldehydes to carboxylic acid and the formation of by-products were not observed. The catalyst could be recovered and reused for at least four reaction cycles without considerable loss of reactivity.
- Manesh, Abbas Amini,Azarin, Khadijeh
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p. 125 - 131
(2016/04/26)
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- Transition Metal Ions as Efficient Catalysts for Vilsmeier-Haack Formylation of Hydrocarbons with Reagents: Kinetics and Mechanism
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The Vilsmeier-Haack formylation reactions with hydrocarbons are sluggish in acetonitrile medium. The VH reactions follows second-order kinetics and affords formyl derivatives under kinetic conditions that are also irrespective of the nature of the oxychloride (POCl3 or SOCl2) used for the preparation of VH reagent along with DMF. However, the reactions undergo significant rate accelerations in the presence of transition metal ions such as Cu(II), Ni(II), Co(II) and Cd(II). Transition metal ion catalyzed VH formylation is explained through the formation of a mixed ligand complex of the [M(II)S(VHR)] type prior to the rate determining rearrangement step, before yielding formyl derivatives of hydrocarbons.
- Rajanna,Ferdose, Aneesa,Rajendar Reddy,Arifuddin,Moazzam Ali
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p. 371 - 394
(2016/03/12)
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- Recognition of Al3+ based on a naphthalene-based "off-On" chemosensor in near 100% aqueous media
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An efficient fluorescent Al3+ sensor, 2-hydroxy-1-naphthylaldehyde nicotinoyl hydrazone (HL) has been designed and synthesized. The receptor shows "off-on" fluorescent responses toward Al3+ in near 100% aqueous media. Other relevant metal ions such as Li+, Na+, K+, Ca2+, Mg2+, Cu2+, Co2+, Mn2+, Ni2+, Zn2+, Ba2+, Fe2+, Cd2+, Hg2+, Pb2+, Sc3+, Fe3+, Cr3+ caused almost no fluorescence increase. The reason for this phenomenon is that the addition of Al3+ to the solution of HL induce the formation of a 1:1 stoichiometry of the binding mode of L-Al(III) which inhibits the excited-state intramolecular proton transfer (ESIPT) and photoinduced electron transfer (PET). More importantly, the reversibility of the recognition process of HL was performed by adding a Al3+ bonding agent Na2EDTA.
- Qin, Jing-Can,Yang, Zheng-Yin,Yang, Peng
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p. 136 - 141
(2015/05/05)
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- A concentration dependent auto-relay-recognition by the same analyte: A dual fluorescence switch-on by hydrogen sulfide via Michael addition followed by reduction and staining for bio-activity
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H2S is shown, for the first time, to play an extraordinary dual role due to its nucleophilicity and reducing property with our single chemosensor, PND [4-(piperidin-1-yl) naphthalene-1,2-dione]. The initial nucleophilic attack via Michael addition (a lower concentration of H2S, blue fluorescence) is followed by the reduction of the 1,2-diketo functionality (a higher concentration of H2S, green fluorescence). This chemosensor, which also shows biological response, is remarkably effective in sensing the same analyte (H2S) at its different concentrations in a relay pathway via a fluorescence "off-on-on" mechanism, and this is also supported by DFT calculation and Cyclic voltammograms.
- Das, Avijit Kumar,Goswami, Shyamaprosad,Dutta, Gorachand,Maity, Sibaprasad,Mandal, Tarun Kanti,Khanra, Kalyani,Bhattacharyya, Nandan
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p. 570 - 576
(2016/01/12)
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- 3-KETOCOUMARINES FOR LED PHOTOCURING
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The present invention relates to 3-ketocoumarines which can be used as photoinitiators in LED photocuring and to a process for curing compositions comprising said 3-ketocoumarines.
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Paragraph 0087; 0088
(2015/10/05)
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- β-Hydroxy-α-naphthaldehyde [2-(quinolin-8′-yloxy) acetyl] hydrazone as an efficient fluorescent chemosensor for Mg2+
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An efficient fluorescent sensor based on β-hydroxy-α-naphthaldehyde [2-(quinolin-8′-yloxy) acetyl] hydrazone (HL) for Mg2+ has been designed and synthesized. The receptor showed "off-on" fluorescent responses toward Mg2+ in acetonitrile. The reasons for this phenomenon is that the addition of Mg2+ to the solution of HL induce the formation of a 1:1 ligand-metal complex which inhibit excited-state intramolecular proton transfer (ESIPT).
- Qin, Jing-Can,Yang, Zheng-Yin,Fan, Long,Wang, Bao-Dui
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- A colorimetric and ratiometric fluorescent turn-on fluoride chemodosimeter and application in live cell imaging: High selectivity via specific SiO cleavage in semi aqueous media and prompt recovery of ESIPT along with the X-ray structures
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A ratiometric fluorescent turn-on probe for fluoride ion, based on modulation of the excited-state intramolecular proton transfer (ESIPT) process by chemodosimetric desilylation pathway is reported. The probe SNBT (silyl protected hydroxynaphthalene benzothiazole moiety) shows a significant increase of ratiometric absorption band at 440 nm and emission band at 477 nm by the deprotection of fluoride mediated silyl bond cleavage in CH3CN-H 2O (8/2, v/v, 25 °C). The test strips based on SNBT and F - are fabricated, which can act as a convenient and efficient F - test kits. Furthermore, the biological application shows that it can be very useful as a selective fluoride probe in the fluorescence imaging of living cells.
- Goswami, Shyamaprosad,Das, Avijit Kumar,Manna, Abhishek,Maity, Anup Kumar,Fun, Hoong-Kun,Quah, Ching Kheng,Saha, Partha
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supporting information
p. 2633 - 2638
(2014/05/06)
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- Single sensor for multiple analytes: Fluorogenic detection of Al 3+ in aqueous media and AcO- in organic media
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A simple novel receptor, designed to have a combination of both oxygen and nitrogen-binding sites for metal ion and hydrogen bond donor sites for anion, was synthesised. The receptor has been explored for the selective detection of cation Al3+ over the other interfering metal ions and anion AcO - against a range of physiologically relevant anions in the fluorescence spectroscopy. The receptor shows a different response to aluminium and acetate in the emission spectra. The binding isotherm and detection limit demonstrate that the receptor is an excellent fluorometric probe for Al 3+ and AcO-.
- Goswami, Shyamaprosad,Das, Avijit Kumar,Aich, Krishnendu,Manna, Abhishek,Fun, Hoong-Kun,Quah, Ching Kheng
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- Facile one-pot transformation of phenols into o-cyanophenols
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The treatment of phenols with paraformaldehyde in the presence of MgCl2 and Et3N in THF at 80 C, followed by reaction with molecular iodine and aq. ammonia at room temperature provided the corresponding o-cyanophenols in moderate to good yields. The present reaction is a one-pot transformation of phenols into o-cyanophenols using much less expensive reagents than are typically used; the reaction is free of both transition-metals and cyanide. The utility of this reaction was highlighted during our preparation of Febuxostat from p-bromophenol.
- Nakai, Yuhta,Moriyama, Katsuhiko,Togo, Hideo
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p. 6077 - 6083
(2015/03/30)
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- A new pyrene-based Schiff-base: A selective colorimetric and fluorescent chemosensor for detection of Cu(II) and Fe(III)
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A new receptor 1 was prepared, for the detection of Cu2+ and Fe3+ in solutions as a colorimetric and fluorescent sensor, respectively. Receptor 1 shows highly selective and sensitive recognition toward Cu2+ and Fe3+ by naked eye UV-Vis and fluorescent color changes in aqueous solution (DMSO/H2O = 8/2, v/v), respectively. The sensitivity toward Cu2+ or Fe3+ was not interfered with by the presence of other metal ions such as Mg2+, Cd2+, Ag+, Zn2+, Ni2+, Co2+, Mn 2+, Cr3+, Ca2+, Na+, Pb 2+, K+, Fe2+, Li+ and Hg 2+ ions. Receptor 1 can be used for semi-quantitative recognition of Cu2+ ions at ppm level. The fluorescence microscopy experiments showed that the receptor is efficient for detection of Fe3+ in vitro, developing a good image of the biological organelles.
- Bhorge, Yeshwant Ramchandra,Tsai, Haw-Tyng,Huang, Keh-Feng,Pape, Albert J.,Janaki, Sudhakar Narasimha,Yen, Yao-Pin
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- Development of pyrazolone and isoxazol-5-one cambinol analogues as sirtuin inhibitors
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Sirtuins are a family of NAD+-dependent protein deacetylases that play critical roles in epigenetic regulation, stress responses, and cellular aging in eukaryotic cells. In an effort to identify small molecule inhibitors of sirtuins for potential use as chemotherapeutics as well as tools to modulate sirtuin activity, we previously identified a nonselective sirtuin inhibitor called cambinol (IC50 ≈ 50 μM for SIRT1 and SIRT2) with in vitro and in vivo antilymphoma activity. In the current study, we used saturation transfer difference (STD) NMR experiments with recombinant SIRT1 and 20 to map parts of the inhibitor that interacted with the protein. Our ongoing efforts to optimize cambinol analogues for potency and selectivity have resulted in the identification of isoform selective analogues: 17 with >7.8-fold selectivity for SIRT1, 24 with >15.4-fold selectivity for SIRT2, and 8 with 6.8- and 5.3-fold selectivity for SIRT3 versus SIRT1 and SIRT2, respectively. In vitro cytotoxicity studies with these compounds as well as EX527, a potent and selective SIRT1 inhibitor, suggest that antilymphoma activity of this compound class may be predominantly due to SIRT2 inhibition.
- Mahajan, Sumit S.,Scian, Michele,Sripathy, Smitha,Posakony, Jeff,Lao, Uyen,Loe, Taylor K.,Leko, Vid,Thalhofer, Angel,Schuler, Aaron D.,Bedalov, Antonio,Simon, Julian A.
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p. 3283 - 3294
(2014/05/20)
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- Manganese nanocatalyst and N-hydroxyphthalimide as an efficient catalytic system for selective oxidation of ethylbenzene, cyclohexene and oximes under aerobic condition
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The catalytic activity of the nano-manganese-catalyst in the aerobic oxidation of ethylbenzene, cyclohexene and oximes were evaluated without the need of any reducing agent, using N-hydroxyphthalimide (2-Hydroxy-1H-isoindole- 1,3-dione; NHPI) under oxygen pressure. The oxidation of ethylbenzene and cyclohexene to acetophenone and 2-cyclohexene-1-one using N-hydroxyphthalimide (2-Hydroxy-1H-isoindole-1,3-dione; NHPI) under oxygen atmosphere in the presence of a SiO2/Al2O3-supported manganese catalyst occurs with conversions of 95 and 99% and selectivities of 99%. The supported manganese is also a suitable and efficient catalyst for the oxidative deprotection of oximes to the corresponding carbonyl compounds. A mild and efficient method has been optimized for manganese catalysts by considering the effect of various parameters such as the reaction time and the amount of catalyst, the temperature and the reusability of the catalyst after several runs without modification. Moreover, some possible mechanisms for the oxidation of ethylbenzene, cyclohexene and oximes have been proposed.
- Habibi,Faraji,Arshadi,Veisi,Gil
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- Competitive intra- and inter-molecular proton transfer in hydroxynaphthyl benzothiazole: Selective ratiometric sensing of acetate
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The receptor, naphthalene based benzothiazole (NHBT) shows acetate selectivity in its absorbance and emission behavior among the various interfering anions. Substantially red shifted absorption band and fluorescence emission of NHBT in pure acetonitrile media were developed which drastically got enhanced upon addition of tetrabutylammonium acetate. Excited-state intermolecular proton transfer in the sensor-anion hydrogen-bonding complex was suggested to be the signaling mechanism. NHBT, a good hydrogen-bonding donor, the ESIPT process is inhibited by the formation of a strong acetate-NHBT intermolecular hydrogen bond complex, and the inhibition mechanism consequently results in ratiometric response in absorption and emission spectroscopy, respectively.
- Goswami, Shyamaprosad,Das, Avijit Kumar,Aich, Krishnendu,Manna, Abhishek
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p. 4215 - 4220
(2013/07/26)
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- Novel fluorescent cephalosporins: Synthesis, antimicrobial activity and photodynamic inactivation of antibiotic resistant bacteria
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Two novel fluorescent cephalosporins, TCA and TBCA, were synthesized and characterized by 1H NMR, 13C NMR, UV-vis, and fluorescence spectroscopies. Biological activity assays demonstrated that TCA inactivated a Klebsiella pneumonia strain that expressed extended-spectrum β-lactamases. Incubation of 6 μM TCA with K. pneumonia cultures resulted in cell death for 84% of the cells after 126 J/cm2 of light irradiation. In vitro, TCA exhibited a MIC = 0.5 μg/mL with Staphylococcus aureus. Kinetic evaluation revealed that TCA and TBCA were substrates for B1 and B3 subclass metallo-β-lactamases. TBCA exhibited stronger binding affinities to the Gram-positive bacterial strains MRSA1, MRSA2, and S. aureus with value of 2.95-6.59 μM per 108 cells/mL.
- Xiao, Jian-Min,Feng, Lei,Zhou, Li-Sheng,Gao, Hui-Zhou,Zhang, Yi-Lin,Yang, Ke-Wu
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p. 150 - 159
(2013/03/13)
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- Novel fluorescent risedronates: Synthesis, photodynamic inactivation and imaging of Bacillus subtilis
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Novel fluorescently-labeled conjugates of risedronate were synthesized using an epoxide linker, enabling conjugation of risedronate via its pyridyl nitrogen with the aromatic succinimidyl esters. The compounds were characterized by using 1H NMR, 13C NMR, 31P NMR, UV-vis and fluorescence emission spectroscopies. Biological activity assays showed that the conjugates 14 and 15 exhibited photodynamic inactivation of Bacillus subtilis (ATCC 6633) with 91% and 47% bacterial lethality at 10 μM upon visible light irradiation, respectively. Both 14 and 15 could be also used for fluorescence imaging of Bacillus subtilis.
- Zhou, Li-Sheng,Yang, Ke-Wu,Feng, Lei,Xiao, Jian-Min,Liu, Cheng-Cheng,Zhang, Yi-Lin,Crowder, Michael W.
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supporting information
p. 949 - 954
(2013/03/14)
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- Efficient catalytic systems based on cobalt for oxidation of ethylbenzene, cyclohexene and oximes in the presence of N-hydroxyphthalimide
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The selective oxidation of ethylbenzene and cyclohexene to acetophenone and 2-cyclohexene-1-one using N-hydroxyphthalimide (NHPI) under oxygen atmosphere in the presence of an SiO2/Al2O3-supported cobalt catalyst occurs with conversions of 83 and 75% and selectivities of 99%. The supported cobalt is also a suitable and efficient catalyst for the oxidative deprotection of oximes to the corresponding carbonyl compounds. The reaction conditions have been optimized considering the effect of various parameters such as reaction time, amount of catalyst, temperature and reusability of the catalyst after several runs. Moreover, some possible mechanisms for the oxidation of ethylbenzene, cyclohexene and oximes have been proposed.
- Habibi,Faraji,Arshadi,Heydari,Gil
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p. 282 - 292
(2015/03/06)
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- 2-Hydroxy-naphth-1-aldehyde phenyl-thiosemicarbazone: Effective thiourea-based sensor for acetate anion
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A novel urea-based sensor displaying selective recognition for AcO - had been designed and synthesized. Experiments showed that sensor 1 can selectively recognize acetate in DMSO. The evaluation of the sensor's interaction with a variety of structurally different anions was performed by UV-vis titration experiments in DMSO. In addition, the nature of interaction between sensor 1 and AcO- was investigated by 1H NMR titrations.
- Lin, Huakuan,Su, Hongyan,Huang, Weiwei,Yang, Zhongyue,Lin, Hai
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experimental part
p. 221 - 225
(2012/09/10)
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- Synthesis of oxadiazoles encompassing naphtho [2,1-b] thiophene as novel antimicrobial agents
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The required starting material ethyl naphtho [2,1-b] furan-2-carboxylate 2 has been synthesized by the reaction between ethyl chloroacetate and 2-hydroxy-1-naphthaldehyde 1, which in turn was obtained by employing Reimer-Tiemann reaction using 2-naphthol. The ester 2 on thionation with phosphorus pentasulphide produced two compounds viz., ethyl naphtho [2,1-b] thiophene-2-carboxylate 3 and ethyl naphtho [2,1-6] furan-2-carbothioate 4. The compounds 3 and 4 were separated by column chromatography and the compound 3 was converted into naphtho [2,1-b] thiophene-2-carbohydrazide 5 by reacting with hydrazine hydrate. The reaction of carbohydrazide 5 with various aromatic aldehydes resulted in the formation of corresponding Schiff bases 6a-e. The synthesis of 5-(naphtho [2,1-b] thiophen-2-yl)-3-(prop-1-en-2-yl)-2,3-dihydro-1, 3,4-oxadiazoles 7a-e was achieved by adopting a simple one pot procedure which involved reaction of Schiff bases 6a-e with acetic anhydride. All the synthesized compounds have been characterized by IR, 1H NMR spectroscopy and mass spectrometry. All the newly synthesized compounds showed moderate to mild antimicrobial activity when evaluated by cup-plate method. These findings indicated that the title compounds have the property to kill the microbes to some extent when compared with standard drug.
- Kusuma,Vaidya,Nagashree,Mahadevan
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p. 309 - 314
(2013/09/24)
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- Hydrolytically stable Schiff base as highly sensitive aluminium sensor
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A highly fluorescence sensitive sensor for selective detection of aluminium (III) and also to differentiate isomeric acids or two isomers of receptors are presented.
- Samanta, Soham,Nath, Bhaskar,Baruah, Jubaraj B.
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body text
p. 98 - 100
(2012/08/27)
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- Insertion of arynes into the carbon-oxygen double bond of amides and its application into the sequential reactions
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The reaction of arynes, generated from ortho-(trimethylsilyl)aryl triflates, with the CO bond of formamides gave salicylaldehyde derivatives via the formation of formal [2+2] adducts. The sequential transformation of arynes into ortho-disubstituted arenes, o-aminoalkylphenols or o-hydroxyalkylphenols, was achieved by one-pot procedure using dialkylzincs.
- Yoshioka, Eito,Miyabe, Hideto
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experimental part
p. 179 - 189
(2012/02/15)
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- A general and convenient route to oxazolyl ligands
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A diverse range of chiral and achiral oxazolyl ligands, which have many applications including catalysis and luminescent devices, are synthesized simply in three steps from readily available and inexpensive phenol and amino alcohol starting materials. The method can be applied to ligands with electron-donating/-withdrawing and sterically demanding/undemanding substituents, and can conveniently be scaled up to >25 g of product.
- Aspinall, Helen C.,Beckingham, Oliver,Farrar, Michael D.,Greeves, Nicholas,Thomas, Christopher D.
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supporting information; experimental part
p. 5120 - 5123
(2011/10/19)
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- Synthesis of symmetrical and asymmetrical azines encompassing naphtho[2,1-b]furan by a novel approach
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The starting material 3-nitro-2-acetylnaphtho[2,1-b]furan (2) was obtained by nitration of 2-acetylnaphtho[2,1-b] furan (1), under mild condition. The compound 1 was synthesized by the reaction of 2-hydroxy-1-naphthaldehyde with chloroacetone, where in both condensation and cyclization took place in single step. The reaction of 3-nitro-2-acetylnaphtho[2,1-b]furan (2) with hydrazine hydrate produced corresponding hydrazone (3) in excellent yield, which on treatment with various aromatic aldehydes under different reaction conditions resulted in the formation of symmetrical azines (4a-e) and unsymmetrical azines (5a-e). All the newly synthesized compounds have been characterized by analytical and spectral studies and were screened for antibacterial antibacterial activity against Bacillus subtilus and Alcaligenes fecalies and antifungal activity against Aspergillus nidulans, Aspergillus parasiticus and Aspergillus terrus. The Second Harmonic Generation (SHG) efficiency of some of the synthesized compounds was measured by powder technique using Nd:YAG laser.
- Veena,Ramaiah,Vanita,Avinash,Vaidya
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body text
p. 354 - 360
(2012/02/05)
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