- Cascade Synthesis of Pyrroles from Nitroarenes with Benign Reductants Using a Heterogeneous Cobalt Catalyst
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A bifunctional 3d-metal catalyst for the cascade synthesis of diverse pyrroles from nitroarenes is presented. The optimal catalytic system Co/NGr-C@SiO2-L is obtained by pyrolysis of a cobalt-impregnated composite followed by subsequent selective leaching. In the presence of this material, (transfer) hydrogenation of easily available nitroarenes and subsequent Paal–Knorr/Clauson-Kass condensation provides >40 pyrroles in good to high yields using dihydrogen, formic acid, or a CO/H2O mixture (WGSR conditions) as reductant. In addition to the favorable step economy, this straightforward domino process does not require any solvents or external co-catalysts. The general synthetic utility of this methodology was demonstrated on a variety of functionalized substrates including the preparation of biologically active and pharmaceutically relevant compounds, for example, (+)-Isamoltane.
- Ryabchuk, Pavel,Leischner, Thomas,Kreyenschulte, Carsten,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
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supporting information
p. 18679 - 18685
(2020/09/02)
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- Design, synthesis, and evaluation of the antimycobacterial activity of 3-mercapto-1,2,4-triazole–pyrrole hybrids
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A series of 3-mercapto-1,2,4-triazole–pyrrole hybrids was designed as antimycobacterial agents by employing 5-(4-(1H-pyrrol-1-yl)phenyl)-4H-1,2,4-triazole-3-thiol as the scaffold onto which several types of moieties were introduced in the triazole ring at N-4 and N-2 and as substituents of the mercapto function. The aforementioned moieties are an allyl or a phenyl moiety at N-4; an aminomethyl group at N-2; or methyl, substituted benzyl, ethoxycarbonylmethyl, or substituted phenacyl at sulfur. Investigation of the compounds in the resulting library as growth inhibitors of Mycobacterium smegmatis showed that their minimum inhibitory concentration was higher than 64 mg/L.
- Roman, Gheorghe,Bost?naru, Andra-Cristina,N?stas?, Valentin,Mare?, Mihai
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p. 531 - 546
(2019/10/02)
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- Synthesis and antitubercular activity of some N'-substituted benzoyl-4-(2,5dimethyl-1H-pyrrolyl) benzohydrazide Derivatives
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Some new substituted dimethylpyrrolyl benzohydrazide derivatives have been synthesized as new antitubercular agents. Dimethylpyrrolyl benzohydrazide derivatives 4(a-j) were synthesized by the reaction of 4-(2,5-dimethyl-1H-pyrrol-1-yl)benzohydrazide (3) with substituted benzoic acids in N', N'-dimethyl formamide using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate, an amide coupling agent and N',N'-Diisopropylethylamine as a catalyst. All the newly synthesized compounds 4(a-j) were screened for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv and compounds have exhibited significant minimum inhibitory concentration values.
- Joshi, Shrinivas D.,Vinayak,Prem Kumar,Dixit, Sheshagiri R.
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p. 195 - 200
(2018/09/14)
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- Synthesis, characterization and antitubercular activities of novel pyrrolyl hydrazones and their Cu-complexes
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Novel pyrrolyl hydrazones and their copper complexes have been synthesized and characterized using analytical and spectral techniques to show the tetrahedral geometry for Cu(II) complexes. Biological activities of hydrazones have been assessed to understand the role of metal ion on their biological activity and the effect of pyrrolyl hydrazones. In?vitro antitubercular activity against Mycobacterium tuberculosis of the metal complexes (13b and 13r) exhibited the highest antitubercular activity that are quite close to rifampicin (0.4?μg/mL), giving a MIC of 0.8?μg/mL. All other compounds showed good activity with the MIC values ranging from 1.6 to 100?μg/mL. A comparative study of inhibition values of the ligands and their complexes showed higher antimicrobial activity of the complexes than the ligands. Some compounds have a good activity against InhA and in particular, compounds 12r, 13b and 13r exhibited more than 60% binding with the enzyme even at 5?μM (exhibited good IC50 upto 2.4?μM). Most of the active molecules have a very less cytotoxicity against the human lung cancer cell-line A549. The docking and 3D-QSAR studies have been carried out to provide some insights into the mechanism of action for this class of compounds.
- Joshi, Shrinivas D.,Kumar, Devendra,Dixit, Sheshagiri R.,Tigadi, Nageshwar,More, Uttam A.,Lherbet, Christian,Aminabhavi, Tejraj M.,Yang, Kap Seung
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- Design, synthesis, molecular docking and 3D-QSAR studies of potent inhibitors of enoyl-acyl carrier protein reductase as potential antimycobacterial agents
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In order to develop a lead antimycobacterium tuberculosis compound, a series of 52, novel pyrrole hydrazine derivatives have been synthesized and screened which target the essential enoyl-ACP reductase. The binding mode of the compounds at the active site of enoyl-ACP reductase was explored using surflex-docking method. The binding model suggests one or two hydrogen bonding interactions between pyrrole hydrazones and InhA enzyme. Highly active compound 5r (MIC 0.2 μg/mL) showed hydrogen bonding interactions with Tyr158 and NAD+ in the same manner as those of ligands PT70 and triclosan. The CoMFA and CoMSIA models generated with database alignment were the best in terms of overall statistics. The predictive ability of the CoMFA and CoMSIA models was determined using a test set of 13 compounds, which gave predictive correlation coefficients (rpred2) of 0.896 and 0.930, respectively.
- More, Uttam A.,Joshi, Shrinivas D.,Aminabhavi, Tejraj M.,Gadad, Andanappa K.,Nadagouda, Mallikarjuna N.,Kulkarni, Venkatrao H.
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p. 199 - 218
(2014/01/06)
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- Synthesis, characterization, biological activity, and 3D-QSAR studies on some novel class of pyrrole derivatives as antitubercular agents
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A new series of pyrrole derivatives have been designed, synthesized, and their structures have been elucidated along with the evaluation of antitubercular activity against Mycobacterium tuberculosis H37Rv using the microplate alamar blue assay method and antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, and Escherichia coli by broth micro-dilution assay method. Structural activity relationships and 3D-QSAR analysis have been carried out by Topomer Comparative Molecular Field Analysis (CoMFA). Training set of 42 and test set of 8 active compounds were used to develop the method that showed cross-validated correlation coefficient (q 2) of 0.815, standard error of prediction of 0.36, non-cross-validated correlation coefficient (r 2) of 0.973, and standard error of estimate of 0.14 with six components. Graphical Abstract: Synthesis; spectral and 3D-QSAR studies; and antibacterial, antitubercular, and cytotoxic activities of a novel series of pyrrole derivatives are described.[Figure not available: see fulltext.]
- Joshi, Shrinivas D.,More, Uttam A.,Dixit, Sheshagiri R.,Korat, Haresh H.,Aminabhavi, Tejraj M.,Badiger, Aravind M.
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p. 1123 - 1147
(2014/03/21)
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- Synthesis of new 4-(2,5-dimethylpyrrol-1-yl)/4-pyrrol-1-yl benzoic acid hydrazide analogs and some derived oxadiazole, triazole and pyrrole ring systems: A novel class of potential antibacterial, antifungal and antitubercular agents
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A series of 4-(2,5-dimethylpyrrol-1-yl)/4-pyrrol-1-yl benzoic acid hydrazide analogs, some derived 1,3,4-oxadiazoles, 5-substituted-4-amino-1,2,4- triazolin-3-thione and 2,5-dimethyl pyrroles have been synthesized in good yields and structures of these compounds were established by IR, 1H NMR, 13C NMR, Mass spectral and elemental analysis. These compounds were evaluated for their preliminary in vitro antibacterial, antifungal and antitubercular activities against Mycobacterium tuberculosis H37Rv strain by broth dilution assay method. Twelve of these compounds displayed good antimicrobial activity, with a minimum inhibitory concentration (MIC) values 1-4 μg mL-1. Several compounds 4, 8d, 9, 12c-d and 12f-h exhibited good in vitro antitubercular activity with MIC values 1-2 μg mL-1. Further, some title compounds were also assessed for their cytotoxic activity (IC50) against mammalian Vero cell lines and A549 (lung adenocarcinoma) cell lines using MTT assay method. The results reveal that these compounds exhibit antitubercular activity at non-cytotoxic concentrations. Graphical Abstract: Synthesis, spectral studies and antibacterial, antifungal and antitubercular activities of a novel series of pyrrole derivatives are described [Figure not available: see fulltext.]
- Joshi,More, Yogesh,Vagdevi,Vaidya,Gadaginamath,Kulkarni
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p. 1073 - 1089
(2013/03/29)
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- Tricyclononene carboxamide derivatives as novel anti-HIV-1 agents
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By modifying the chemical structure of anti-orthopoxvirus compound ST-246, we designed and synthesized a series of tricyclononene carboxamide derivatives and tested their anti-HIV-1 activity and cytotoxicity. We found that benzoimidazol-containing compound 7g was highly effective in inhibiting HIV-1 R5 infection with an IC50 value of 0.41 μM and a selectivity index of 292, but it exhibited no significant inhibitory activity on HIV-1 reverse transcriptase, integrase and protease. CoMFA was used to analyze structure-activity relationships with good predictive power (r2 = 0.921; q2 = 0.582). Moreover, the CoMFA model showed that the length of the molecule, the amide, and the amine moieties all played crucial roles in anti-HIV activity. These results suggest that 7g may serve as a lead for the development of novel anti-HIV-1 therapies. A series of tricyclononene carboxamide derivatives based on anti-orthopoxvirus compound ST-246 were synthesized and characterized as novel anti-HIV-1 agents.
- Dong, Ming-Xin,Zhang, Jian,Peng, Xu-Qing,Lu, Hong,Yun, Liu-Hong,Jiang, Shibo,Dai, Qiu-Yun
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experimental part
p. 4096 - 4103
(2010/10/02)
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