- Green synthesis of Ag@Au bimetallic regenerated cellulose nanofibers for catalytic applications
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The green synthesis of nanocomposites has attracted huge consideration in recent years due to its positive environmentally friendly impact. The present study reports the first bimetallic Ag-Au cellulose nanofiber composite (Ag@Au/CNCs) prepared via a very simple green preparation method. An aqueous leaves extract of Moringa oleifera was used to obtain the bimetallic Ag@Au/CNC nanocomposite. High-resolution transmission electron microscopy (HRTEM) observations revealed the successful formation of triangle, hexagonal, and spherical shapes of well-combined Ag-Au nanoparticles on the regenerated cellulose nanofiber surface. Further, the formation of Au-Ag bimetallic nanostructures was confirmed by X-ray photoelectron spectroscopy (XPS) and X-ray crystallography (XRD) results. The resultant bimetallic Ag@Au/CNC catalyst was found to perform remarkably well in the reduction of nitrophenols. The bimetallic Ag@Au/CNC catalyst gave excellent kapp values of 15.59 and 22.83 × 10-3 s-1 for the 2- A nd 4-nitrophenol reduction process, respectively. To our delight, the Ag@Au/CNC catalyst was found to perform well in the aza-Michael reaction. The catalytic activity of Ag@Au/CNCs was compared with mono-metallic Ag/CNCs, Au/CNCs, and other reported catalysts. Based on the results obtained, the high synergy of Ag@Au/CNCs was explained. A possible mechanism is proposed for the Ag@Au/CNC-catalyzed nitrophenol reduction and aza-Michael reactions.
- Gopiraman, Mayakrishnan,Saravanamoorthy, Somasundaram,Baskar, Ramaganthan,Ilangovan, Andivelu,Ill-Min, Chung
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- Cu-nanoparticles: A chemoselective catalyst for the aza-Michael reactions of N-alkyl- and N-arylpiperazines with acrylonitrile
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A novel method for effecting the aza-Michael reactions of N-alkyl- and N-arylpiperazines with acrylonitrile using Cu-nanoparticles is described. The method features the use of 10 mol % Cu (14-17 nm) nanoparticles under mild reaction conditions to afford the addition products in good to excellent yields. The Cu-nanoparticles selectively catalysed the aza-Michael reaction of N-alkyl- and N-arylpiperazines in the presence of aromatic amino or aliphatic hydroxy groups.
- Verma, Akhilesh K.,Kumar, Rupesh,Chaudhary, Preeti,Saxena, Amit,Shankar, Ravi,Mozumdar, Subho,Chandra, Ramesh
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- Development of novel multipotent compounds modulating endocannabinoid and dopaminergic systems
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Polypharmacology approaches may help the discovery of pharmacological tools for the study or the potential treatment of complex and multifactorial diseases as well as for addictions and also smoke cessation. In this frame, following our interest in the de
- Grillo, Alessandro,Chemi, Giulia,Brogi, Simone,Brindisi, Margherita,Relitti, Nicola,Fezza, Filomena,Fazio, Domenico,Castelletti, Laura,Perdona, Elisabetta,Wong, Andrea,Lamponi, Stefania,Pecorelli, Alessandra,Benedusi, Mascia,Fantacci, Manuela,Valoti, Massimo,Valacchi, Giuseppe,Micheli, Fabrizio,Novellino, Ettore,Campiani, Giuseppe,Butini, Stefania,Maccarrone, Mauro,Gemma, Sandra
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- Synthesis, antifungal evaluation and molecular docking studies of some tetrazole derivatives
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A facile and simple protocol for the [3+2] cycloaddition of alkyl nitriles (RCN) with sodium azide (NaN3) in the presence of copper bis(diacetylcurcumin) 1,2-diamin-obenzene Schiff base complex, SiO2-[Cu-BDACDABSBC] as a heterogeneous catalyst in the presence of ascorbic acid and a solution of water/i-PrOH (50:50, V/V) media at reflux condition is described. The supported catalyst was prepared by immobilization of a copper bis(diacetylcurcumin) 1,2-diaminobenzene Schiff base complex [Cu-BDACDABSBC] on silica gel. The complex has high selectivity, catalytic activity, and recyclability. The significant features of this procedure are high yields, broad substrate scope and simple and efficient work-up procedure. According to this synthetic methodology, excellent yields of 5-substituted 1H-tetrazoles having bioactive N-heterocyclic cores were synthesized. The in vitro antifungal activities of title compounds were screened against various pathogenic fungal strains, such as Candida species involving C. albicans, C. glabrata, C. krusei, C. parapsilosis as well as filamentous fungi like Aspergillus species consisting of A. fumigatus and A. flavus. The molecular docking analysis is discussed for one most potent compound against fungi. The docking study determined a remarkable interaction between the most potent compounds and the active site of Mycobacterium P450DM.
- Afsarian, Mohammad Hosein,Farjam, Mojtaba,Zarenezhad, Elham,Behrouz, Somayeh,Rad, Mohammad Navid Soltani
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p. 874 - 887
(2020/01/21)
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- Cultivation of a Cu/HMPC catalyst from a hyperaccumulating mustard plant for highly efficient and selective coupling reactions under mild conditions
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Cu-containing activated carbon (eco-catalyst, Cu/HMPC, where 'C' defines 'carbon') was derived from a metal-hyperaccumulating mustard plant (HMP) by a simple chemical activation method. Transmission electron microscopy/selected area diffraction (HRTEM/SAED) results revealed that the Cu/HMPC has mainly three types of morphology [sheet-like morphology (2D), hollow-spheres (3D) and needle-like structures (1D)] which are interconnected. HRTEM-SAED, Raman and X-ray photoelectron spectroscopy (XPS) results confirmed the existence of Cu oxide species in Cu/HMPC. Content of Cu in Cu/HMPC was determined to be 1.03 wt%. The quality of graphitization in Cu/HMPC was discussed by using Raman and XRD results. The BET surface area of Cu/HMPC was determined to be 620.8 m2 g-1. The Cu/HMPC actively transformed a wide range of amines to imines under very mild reaction conditions. The catalyst Cu/HMPC gave products in excellent yields (98-61%) with very high TON/TOF values (1512/339-833/35 h-1). To the best of our knowledge, this is the most efficient Cu-based heterogeneous eco-catalyst for the synthesis of imines among those reported to date. The Cu can be recovered from used Cu/HMPC by a simple HCl treatment. Versatility, heterogeneity and reusability of Cu/HMPC were tested. A possible mechanism has been proposed.
- Gopiraman, Mayakrishnan,Wei, Kai,Zhang, Ke-Qin,Chung, Ill-Min,Kim, Ick Soo
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p. 4531 - 4547
(2018/02/09)
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- N-Arylation of DABCO with Diaryliodonium Salts: General Synthesis of N-Aryl-DABCO Salts as Precursors for 1,4-Disubstituted Piperazines
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Employing DABCO as a substrate, aryl(mesityl)iodonium triflates are introduced as arylating agents for a tertiary sp3-nitrogen. Mild conditions and exceptional selectivity of the aryl group transfer allow unprecedented N-aryl-DABCO salts to be obtained, bearing substituents of different electronic natures. This metal-free methodology has no analogy among known transition-metal-based reactions. The utility of isolated N-aryl-DABCO salts is demonstrated for the preparation of flibanserin.
- Bugaenko, Dmitry I.,Yurovskaya, Marina A.,Karchava, Alexander V.
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p. 6389 - 6393
(2018/10/09)
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- An efficient protocol for facile synthesis of new 5-substituted-1H-tetrazole derivatives using copper-doped silica cuprous sulfate (CDSCS) as heterogeneous nano-catalyst
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A facile and highly efficient protocol for synthesis of new 5-substituted-1H-tetrazoles derivatives using copper-doped silica cuprous sulfate (CDSCS) is described. In this method, the cycloaddition reaction of sodium azide with structurally diverse nitriles involving bioactive N-heterocyclic cores exploiting CDSCS in refluxing H2O/i-PrOH (1:1, v/v) furnishes the corresponding 5-substituted-1H-tetrazoles in good to excellent yields (up to 93percent). The influence of parameters effective in progress of reaction including solvent type, temperature and catalyst was studied and discussed. In this protocol, CDSCS was proved to be an efficient heterogeneous nano-catalyst to easily achieve the new tetrazole derivatives. The advantages of CDSCS in current protocol known are its cheapness, thermal and chemical stability, ease of recyclability and reusability for several consecutive runs without significant decline in its reactivity.
- Soltani Rad, Mohammad Navid
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- Cu/Graphene/Clay Nanohybrid: A Highly Efficient Heterogeneous Nanocatalyst for Synthesis of New 5-Substituted-1H-Tetrazole Derivatives Tethered to Bioactive N-Heterocyclic Cores
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A series of new 5-substituted 1H-tetrazoles bearing bioactive N-heterocyclic cores were synthesized through [3 + 2] cycloaddition reactions between alkyl nitriles (RCN) and NaN3in the presence of Cu/aminoclay/reduced graphene oxide nanohybrid (Cu/AC/r-GO nanohybrid) as a heterogeneous nanocatalyst in water/i-PrOH (50:50, V/V) media at reflux condition. The influence of factors on a sample reaction including solvent type, temperature, and catalyst amount was discussed. This current protocol has many advantages including inexpensiveness, environmentally benign, broad substrate scope, excellent yields, and easy work-up procedure. The Cu/AC/r-GO used in this protocol is a low-cost catalyst that proved to have considerable chemical and thermal stabilities. This non-hygroscopic catalyst can be easily recycled, reused, and stored for many consecutive reaction runs without significant loss in its reactivity.
- Soltani Rad, Mohammad Navid,Behrouz, Somayeh,Sadeghi Dehchenari, Vahid,Hoseini, S. Jafar
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p. 355 - 365
(2017/02/03)
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- Synthesis and pharmacological evaluation of [(4-Arylpiperazin-1-yl)-alkyl]- carbamic acid ethyl ester derivatives as potential anxiolytic agents
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On the basis of our earlier studies, a series of N-{4-[4-(aryl) piperazin-1-yl]-phenyl}-amine derivatives containing terminal carbamoyl fragment with alkyl spacer of different lengths (15-20) were synthesized as ligands, for 5-hydroxytryptamine-1A (5-HT1A
- Khatri, Manisha,Rai, Santosh K.,Ranbhor, Ranjit,Kishore, Krishna,Tiwari, Manisha
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experimental part
p. 1143 - 1152
(2012/11/07)
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- Further structure-activity relationships study of hybrid 7-{[2-(4-phenylpiperazin-1-yl)ethyl]propylamino}-5,6,7,8-tetrahydronaphthalen-2- ol analogues: identification of a high-affinity D3-preferring agonist with potent in vivo activity with long duration
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This paper describes an extended structure-activity relationships study of aminotetralin-piperazine-based hybrid molecules developed earlier for dopamine D2/D3 receptors. Various analogues as positional isomers have been developed where location of the ph
- Biswas, Swati,Zhang, Suhong,Fernandez, Fernando,Ghosh, Balaram,Zhen, Juan,Kuzhikandathil, Eldo,Reith, Maarten E. A.,Dutta, Aloke K.
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p. 101 - 117
(2008/09/20)
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- Triethylammonium acetate (TEAA): A recyclable inexpensive ionic liquid promotes the chemoselective aza- and thia-Michael reactions
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A new, highly efficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using triethylammonium acetate (TEAA) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.
- Verma, Akhilesh K.,Attri, Pankaj,Chopra, Varun,Tiwari, Rakesh K.,Chandra, Ramesh
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experimental part
p. 1041 - 1047
(2009/11/30)
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- Cadmium chloride (CdCl2): An efficient catalyst for conjugate addition of amines to electron-poor alkenes
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Electron-deficient olefins undergo rapid Aza-Michael reaction with a wide range of amines catalyzed by cadmium chloride at room temperature. Copyright Taylor & Francis Group, LLC.
- Vijender, Medamoni,Kishore,Satyanarayana
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p. 591 - 594
(2007/10/03)
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- Significant rate acceleration of the aza-Michael reaction in water
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The addition of amines to conjugated alkenes has been carried out in water at room temperature very efficiently without any catalyst. Significant rate acceleration of this reaction is observed in water compared to organic solvents.
- Ranu, Brindaban C.,Banerjee, Subhash
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p. 141 - 143
(2007/10/03)
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- Synthesis, characterization and in vitro biological studies of novel cyano derivatives of N-alkyl and N-aryl piperazine
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Cyano derivatives of N-alkyl and N-aryl piperazine have been synthesized and screened for antibacterial and antifungal activities. All the synthesized compounds showed the antibacterial activity against pathogenic strains of Staphylococcus aureus (MTCCB 737), Pseudomonas aeruginosa (MTCCB 741), Streptomyces epidermidis (MTCCB 1824) and Escherichia coli (MTCCB 1652) and antifungal activity against pathogenic strains of Aspergillus fumigatus (ITCC 4517), Aspergillus flavus (ITCC 5192) and Aspergillus niger (ITCC 5405). All compounds showed mild to moderate antimicrobial activity. However, compounds 3c, 4a and 6 showed potent antibacterial activity against pathogenic strains used in the study. Compounds 3a, 3b, 4b, and 4d showed mild to moderate antifungal activity against Aspergillus pathogenic strains. The compounds reported in this study were assessed for there cytotoxicity using MTT colorimetric assay on Hela cells. All the compounds showed cell viability more than the control drug gentamicin, with compound 2 having highest i.e. 95% cell viability.
- Chaudhary, Preeti,Nimesh, Surendra,Yadav, Veena,Verma, Akhilesh Kr.,Kumar, Rupesh
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p. 471 - 476
(2008/02/07)
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- Ceric ammonium nitrate catalyzed aza-Michael addition of aliphatic amines to α,β-unsaturated carbonyl compounds and nitriles in water
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Ceric ammonium nitrate (3 mol%) efficiently catalyzes the aza-Michael reaction of amines with α,β-unsaturated carbonyl compounds in water to produce the corresponding β-amino carbonyl compounds in good to excellent yields (55-99%) for most of the compounds under mild conditions. The reaction is procedurally simple and displays limited chemoselectivity, as aromatic amines were found to be unreactive. Georg Thieme Verlag Stuttgart.
- Varala, Ravi,Sreelatha, Nuvula,Adapa, Srinivas R.
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p. 1549 - 1553
(2007/10/03)
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- Optically active antifungal azoles: Synthesis and antifungal activity of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-{2-[4-aryl-piperazin-1-yl]-ethyl} -tetrazol-2-yl/1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol
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A series of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-{2-[4-aryl-piperazin-1-yl]- ethyl}-tetrazol-2-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (11a-n) and (2R,3S)-2-(2,4-difluorophenyl)-3-(5-{2-[4-aryl-piperazin-1-yl]-ethyl} -tetrazole-1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (12a-n) has been synthesized. The antifungal activity of compounds was evaluated by in vitro agar diffusion and broth dilution assay. Compounds 11d and its positional isomer 12d having 3-trifluoromethyl substitution on the phenyl ring of piperazine demonstrated significant antifungal activity against variety of fungal cultures (Candida spp. C. neoformans and Aspergillus spp.). The compound 12d showed MIC value of 0.12μg/mL for C. albicans, C. albicans V-01-191A-261 (resistant strain); 0.25μg/mL for C. tropicalis, C. parapsilosis ATCC 22019 and C. krusei and MIC value of 0.5μg/mL for C. glabrata, C. krusei ATCC 6258, which is comparable to itraconazole and better than fluconazole. Further, compound 11d showed significant activity (MIC; 0.25-0.5μg/mL) against Candida spp. and strong anticryptococcal activity (MIC; 0.25μg/mL) against C. neoformans.
- Upadhayaya, Ram Shankar,Sinha, Neelima,Jain, Sanjay,Kishore, Nawal,Chandra, Ramesh,Arora, Sudershan K.
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p. 2225 - 2238
(2007/10/03)
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- Synthesis of deuterium-labeled antihypertensive 3-(4'-phenyl-1- piperazlnyl)-propyl-2,4-quinazolinedione
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Synthesis of deuterium-labeled 3-(4-phenyl-1-piperazinyl)-propyl- 2,4quinazolinedione (Pelanserine) an anti-hypertensive agent.
- Garcia,Somanathan,Rivero,Aguirre,Hellberg
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p. 2707 - 2711
(2007/10/03)
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- Design, synthesis and biological evaluation of 1,3-diaminopropanes: A new class of polyamine analogs as leishmanicidal agents
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Analogs of 1,3-diaminopropane as inhibitors for the growth of Leishmania donovani have been synthesized and evaluated for their antileishmanial activity. Of the many active compounds, 1-(3-N,N-bis methoxycarbonyl guanidino)propyl-4- methylpiperidine piperazine (4e,f) exhibited significant in vivo inhibitory efficacy against L. donovani by oral and intraperitoneal route of administration.
- Kumar, Versha Vinay,Singh, Sudhir K.,Sharma,Bhaduri,Gupta, Suman,Zaidi, Alima,Tiwari, Suman,Katiyar
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p. 675 - 680
(2007/10/03)
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