- Synthesis, biological evaluation, and enzyme assay of some 5-N-substituted-2-N-(arylsulphonyl)-L(+)glutamines as potential anticancer agents
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Thirty 5-N-substituted-2-N-(arylsulphonyl)-L(+)glutamines were synthesized and evaluated biologically for their anticancer activities. The best active compound of this series showed 92.92% inhibition of tumor weight against Ehrlich Ascites Carcinoma cells. The most active compound was proved to be a competitive inhibitor of glutaminase in the enzyme assay. The best active compound may be a starting point to generate 'lead' for further exploration.
- Jha, Tarun,Samanta, Soma,Halder, Amit Kumar,Adhikari, Nilanjan,Abdul Amin,Sanyal, Arpita,Mukherjee, Tanmoy
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p. 1259 - 1264
(2020/12/04)
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- Three-Component, Interrupted Radical Heck/Allylic Substitution Cascade Involving Unactivated Alkyl Bromides
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Developing efficient and selective strategies to approach complex architectures containing (multi)stereogenic centers has been a long-standing synthetic challenge in both academia and industry. Catalytic cascade reactions represent a powerful means of rapidly leveraging molecular complexity from simple feedstocks. Unfortunately, carrying out cascade Heck-type reactions involving unactivated (tertiary) alkyl halides remains an unmet challenge owing to unavoidable β-hydride elimination. Herein, we show that a modular, practical, and general palladium-catalyzed, radical three-component coupling can indeed overcome the aforementioned limitations through an interrupted Heck/allylic substitution sequence mediated by visible light. Selective 1,4-difunctionalization of unactivated 1,3-dienes, such as butadiene, has been achieved by employing different commercially available nitrogen-, oxygen-, sulfur-, or carbon-based nucleophiles and unactivated alkyl bromides (>130 examples, mostly >95:5 E/Z, >20:1 rr). Sequential C(sp3)-C(sp3) and C-X (N, O, S) bonds have been constructed efficiently with a broad scope and high functional group tolerance. The flexibility and versatility of the strategy have been illustrated in a gram-scale reaction and streamlined syntheses of complex ether, sulfone, and tertiary amine products, some of which would be difficult to access via currently established methods.
- Bellotti, Peter,Glorius, Frank,Heidrich, Bastian,Huang, Huan-Ming,Pflüger, Philipp M.,Schwarz, J. Luca
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supporting information
p. 10173 - 10183
(2020/06/27)
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- Propanolysis of arenesulfonyl chlorides: Nucleophilic substitution at sulfonyl sulfur
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We have studied the mechanism of solvolysis of arenesulfonyl chlorides by propan-1-ol and propan-2-ol at 303-323 K. Kinetic profiles were appropriately fit by first-order kinetics. Reactivity increases with electron-donating substituents. Ortho-alkyl substituted derivatives of arenesulfonyl chlorides show increased reactivity, but the origin of this “positive” ortho-effect remains unclear. Likely, ortho-methyl groups restrict rotation around the C-S bond, facilitating the attack of the nucleophile. No relevant reactivity changes have been found with propan-1-ol and propan-2-ol in terms of nucleophile steric effect. The existence of isokinetic relationships for all substrates suggests a single mechanism for the series. Solvolysis reactions of all substrates in both alcohols show isokinetic temperatures (Tiso) close to the working temperature range, which is an evidence of the process being influenced by secondary reactivity factors, likely of steric nature in the TS. Solvation plays a relevant role in this reaction, modulating the reactivity. In some cases, the presence of t-Bu instead of Me in para- position leads to changes in the first solvation shell, increasing the energy of the reaction (ca. 1?kJ·mol?1). The obtained results suggest the same kinetic mechanism of solvolysis of arenesulfonyl chlorides for propan-1-ol and propan-2-ol, as in MeOH and EtOH, where bimolecular nucleophilic substitution (SN2) takes place with nucleophilic solvent assistance of one alcohol molecule and the participation of the solvent network involving solvent molecules of the first solvation shell.
- Iazykov, Mykyta,Canle, Moisés,Santaballa, J. Arturo,Rublova, Ludmila
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supporting information
(2017/09/08)
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- Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds
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Alcoholysis rates of unhindered benzenesulfonyl chlorides (X-ArSO2Cl, X = H-; 4-Br-; 4-Me-) are similar in methanol; the same behavior is also observed in ethanol, whereas the reactivity order in iso-propanol is 4 Me- 2Cl) (X = 2,4,6-Me3-3-NO2-; 2,6-Me2-4-tBu-; 2,4,6-Me3-; 2,3,5,6-Me4-; 2,4,6-iPr3-; 2,4-Me2-; 2,4,6-(OMe)3-) in all studied alcohols show a significant increase in reactivity, the so-called positive steric effect. Most of the substrates showed a reaction order b ~ 2 with respect to the nucleophile in methanol and ethanol, and b ~ 3 in iso-propanol. The correlation between reactivity and the Kirkwood function (1/ξ) gives negative sensitivity (U) for all systems. All substrates showed high sensitivity to media nucleophilicity that depends on ΣσX. Obtained results suggest the alcoholysis of benzenesulfonyl chlorides proceeds through SN2 mechanism where the transition state (TS) involves the participation of 2–3 alcohol molecules; such a TS can be cyclic, in the case of unbranched alcohols, or linear, for alcohols with bulkier hydrocarbon groups like iso-propanol. To include the number of alcohol molecules playing such a role in the TS, the following terminology is proposed: cSN2sn for SN2 reactions involving n solvent molecules in a cyclic (c) TS, where “s” stands for the solvent and “n” is either the closest integer or half-integer to the reaction order relative to the solvent or, in computational studies, the proposed number of solvent molecules taking part in the TS, whereas SN2sn is proposed when the TS is not cyclic. Copyright
- Iazykov, Mykyta,Rublova, Ludmila,Canlel, Moisés,Santaballa, J. Arturo
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- Possible anticancer agents: synthesis, pharmacological activity, and molecular modeling studies on some 5-N -Substituted-2-N-(substituted benzenesulphonyl)-L(+)Glutamines
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On the basis of our earlier work, fortyone 5-N-substituted-2N-(substituted benzenesulphonyl)-L(+)glutamines were synthesized and screened for cancer cell inhibitory activity. The best active compounds showed 91% tumor cell inhibition, whereas other three compounds showed more than 80% inhibition. Two-dimensional quantitative structure–activity relationship modeling and three-dimensional quantitative structure–activity relationship k-nearest neighbor molecular field analysis studies were done to get an insight into structural requirements toward further improved anticancer activity. Considering the fact that these compounds are competitive inhibitors of glutaminase, a molecular docking study followed by molecular dynamic simulation analysis were performed. The work may help to develop new anticancer agents.
- Jha, Tarun,Basu, Soumya,Halder, Amit Kumar,Adhikari, Nilanjan,Samanta, Soma
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p. 1437 - 1458
(2017/06/05)
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- NOVEL SULPHONAMIDE DERIVATIVES AS GLUCOCORTICOID RECEPTOR MODULATORS FOR THE TREATMENT OF INFLAMMATORY DISEASES
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A compound of formula (I) or a pharmaceutically acceptable salt thereof; compositions comprising them, processes for preparing them and their use in medical therapy (for example modulating the glucocorticoid receptor in a warm blooded animal).
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Page/Page column 30
(2008/06/13)
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- NOVEL SULPHONAMIDE DERIVATIVES AS GLUCOCORTICOID RECEPTOR MODULATORS FOR THE TREATMENT OF INFLAMMATORY DISEASES
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Compounds of formula (I) or a pharmaceutically acceptable salt thereof; compositions comprising them, processes for preparing them and their use in medical therapy (for example modulating the glucocorticoid receptor in a warm blooded animal).
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Page/Page column 78
(2008/06/13)
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- Catalytic kinetic resolution of 5-alkoxy-2(5H)-furanones
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The kinetic resolution of racemic 5-alkoxy-2(5H)-furanones, using a chiral aminoalcohol catalyzed 1,4-addition of arylthiols, was examined. Using various butenolides it was shown that a γ-alkoxy substituent appears to be essential to reach high enantioselectivities whereas electron-donating substituents in the arylthiols also increase the selectivity. Cinchona alkaloids are the preferred catalysts for the kinetic resolution, with quinine and quinidine leading to the most efficient and selective thiol additions. A remarkable dilution effect and a strong dependency on the mode of addition of reactants were observed. Optimization studies are presented of the kinetic resolution of 5-methoxy-2(5H)-furanone 2 resulting in (R)-2 or (S)-2 with enantiomeric excesses exceeding 90%. A mechanism for the quinine (quinidine) catalyzed kinetic resolution is given.
- Faber, Wijnand S.,Kok, Johan,De Lange, Ben,Feringa, Ben L.
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p. 4775 - 4794
(2007/10/02)
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- CATALYTIC SULFONYLATION OF PHENOL BY STERICALLY HINDERED SULFONYL CHLORIDES
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The sulfonylation of phenol by substituted arenesulfonyl chlorides XArSO2Cl in the presence of triethylamine in benzene was studied by potentiometric titration.A linear relation was obtained between the logaritmhs of the catalytic rate constants and the steric constants Eso of the substituents in the sulfonyl chloride.The contribution from the induction and steric effects of the substituents at position2 to the kinetics of the process was assessed.It was concluded that the steric effect plays a predominant role over the induction and resonance effects.
- Vizgert, R.V.,Maksimenko, N.N.,Rubleva, L.I.
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p. 2144 - 2146
(2007/10/02)
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