- Visible Light-Mediated [2 + 2] Cycloaddition Reactions of 1,4-Quinones and Terminal Alkynes
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A single-step synthesis of 4-hydroxy-functionalized bi-aryl and aryl/alkyl ketones via oxidative coupling of terminal alkynes with benzoquinones is reported. Furthermore, with naphthoquinones, owing to the cross-resonance of carbonyl with the aromatic ring, alkene-alkyne cycloaddition is more favored to give four-membered carbocyclic adducts, thereby precluding the requirement of preactivated alkynes.
- Sultan, Shaista,Bhat, Muneer-Ul-Shafi,Rizvi, Masood Ahmad,Shah, Bhahwal Ali
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p. 8948 - 8958
(2019/08/12)
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- Iron(III)-Catalyzed Hydration of Unactivated Internal Alkynes in Weak Acidic Medium, under Lewis Acid-Assisted Br?nsted Acid Catalysis
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Alkylarylalkynes are converted with full regioselectivity into the corresponding arylketones by formal hydration of the triple bond under weak acidic conditions, at times and temperatures (≤95 °C) comparable to those used for terminal alkynes. The process catalyzed by Fe2(SO4)3nH2O in glacial acetic acid exhibits good functional group compatibility, including that with bulky triple bond substituents, and can be extended to the one-pot transformation of aryltrimethylsilylacetylenes into acetyl derivatives via a desilylation-hydration sequence. The overall reactivity pattern along with proton affinity data indicate that the triple bond is activated by proton transfer rather than by π-interaction with the metal ion. This mechanistic feature, at variance with that of noble metal catalysts, accounts for the total regioselectivity and the insensitivity to steric hindrance exhibited by the Fe2(SO4)3nH2O/AcOH catalytic system. (Figure presented.).
- Antenucci, Achille,Flamini, Piergiorgio,Fornaiolo, Marco Valerio,Di Silvio, Sergio,Mazzetti, Sara,Mencarelli, Paolo,Salvio, Riccardo,Bassetti, Mauro
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p. 4517 - 4526
(2019/08/26)
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- Synthesis, biochemical evaluation and rationalisation of a series of 3,5- dibromo derivatives of 4-hydroxyphenyl ketone-based compounds as probes of the active site of type 3 of 17β-hydroxysteroid dehydrogenase (17β-hsd3) and the role of hydrogen bonding interaction in the inhibition of 17β-HSD3
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We report the synthesis, evaluation and rationalisation of the inhibitory activity of a series of 3,5-dibromo derivatives of 4-hydroxyphenyl ketone as probes of the active site of the type 3 of 17β-hydroxysteroid dehydrogenase (17β-HSD3). The results support the important role of hydrogen bonding interaction in the inhibition of 17β-HSD3.
- Olusanjo, Moniola S.,Mashru, Shreena N.,Cartledge, Timothy,Ahmed, Sabbir
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scheme or table
p. 604 - 610
(2012/08/28)
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- Synthesis and critical micelle concentration of a series of gemini alkylphenol polyoxyethylene nonionic surfactants
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A series of gemini n-alkylphenol polyoxyethylene surfactants (GAP) were successfully synthesized and their molecular structure were confirmed by NMR and FTIR spectrum. Using the same synthesis route, a Gemini nonylphenol polyoxyethylene surfactant (GNP) was synthesized using an industrial nonylphenol product and paraformaldehyde, and its molecular structure was also characterized by 1H-NMR and FTIR spectra. The optimal reaction conditions were established. The critical micelle concentration (CMC) values of GAP were determined by means of Wilhelmy plate method and steady-state fluorescence probe method. The experimental results show how the lengths of the hydrophilic polyoxyethylene chain and the hydrophobic tail alter the CMC values. The CMC values of the GAP are found to be much lower than those of corresponding conventional single tail nonionic surfactants of the polyethoxylated alkylphenol type, which indicates that the gemini species exhibit a better surface activity. AOCS 2011.
- Yang, Fang,Li, Gang,Xu, Nian,Liu, Rong,Zhang, Song-Mei,Wu, Zeng-Jiang
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experimental part
p. 339 - 345
(2012/06/30)
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- Synthesis and biochemical evaluation of a series of trifluoromethanesulfonate derivatives of 4 hydroxyphenyl ketones - Probes of the active site of type 1 and 3 of the 17β-hydroxysteroid dehydrogenase family of enzymes
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In an effort to aid the design of 'dual-inhibitors' of types 1 and 3 of the 17β-hydroxysteroid dehydrogenase (17β-HSD), we report the synthesis, biochemical evaluation and rationalisation of the inhibitory activity of trifluoromethanesulfonate derivatives of 4-hydroxyphenyl ketone-based compounds which were found to be weak inhibitors of types 1 and 3.
- Olusanjo, Moniola S.,Cartledge, Timothy,Shah, Kruti,Ahmed, Sabbir
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p. 253 - 259
(2013/01/10)
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- Palladium(0) nanoparticle-catalyzed sp2 C-H activation: A convenient route to alkyl-aryl ketones by direct acylation of aryl bromides and iodides with aldehydes
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Palladium(0) nanoparticles efficiently catalyze aliphatic aldehyde C-H functionalization by aryl halides to produce alkyl-aryl ketones in good yields. A wide range of substituted aryl and hetero-aryl bromides/iodides and open-chain aldehydes of varied chain length participated in this reaction.
- Adak, Laksmikanta,Bhadra, Sukalyan,Ranu, Brindaban C.
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experimental part
p. 3811 - 3814
(2010/08/19)
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- Synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a series of 4-hydroxyphenyl ketones as potential inhibitors of 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3)
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We report the preliminary results of the synthesis and biochemical evaluation of a number of 4-hydroxyphenyl ketones as inhibitors of the isozyme of the enzyme 17β-hydroxysteroid dehydrogenase (17β-HSD) responsible for the conversion of androstenedione (AD) to testosterone (T), more specifically type 3 (17β-HSD3). The results of our study suggest that we have synthesised compounds which are, in general, potent inhibitors of 17β-HSD3, in particular, we discovered that 1-(4-hydroxy-phenyl)-nonan-1-one (8) was the most potent (IC50 = 2.86 ± 0.03 μM). We have therefore provided good lead compounds in the synthesis of novel non-steroidal inhibitors of 17β-HSD3.
- Lota, Rupinder K.,Dhanani, Sachin,Owen, Caroline P.,Ahmed, Sabbir
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p. 4519 - 4522
(2007/10/03)
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- Novel inhibitors of the enzyme estrone sulfatase (ES)
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We report the initial results of our study into a series of simple 4-sulfamated phenyl alkyl ketones as potential inhibitors of the enzyme estrone sulfatase. The results of the study show that these compounds are potent inhibitors, possessing greater inhibitory activity than COUMATE, but weaker activity than EMATE. Furthermore, the compounds are observed to be irreversible inhibitors.
- Ahmed, Sabbir,James, Karen,Owen, Caroline P,Patel, Chirag K,Patel, Mijal
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p. 841 - 844
(2007/10/03)
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- Hydrophobicity, a physicochemical factor in the inhibition of the enzyme estrone sulfatase (ES)
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We report the initial structure-activity relationship study (SAR) (in particular log P) of a series of compounds based upon 4-sulfamated phenyl ketones as potent inhibitors of the enzyme estrone sulfatase (ES). The results of the study show that these compounds are irreversible inhibitors of ES and that they are more potent than COUMATE, but weaker than EMATE. Analysis of the SAR data shows a strong correlation between IC50 and log P but also supports our previous study, which suggests a very strong relationship between pKa and IC50.
- Ahmed, Sabbir,James, Karen,Owen, Caroline P.,Patel, Chirag K.,Patel, Mijal
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p. 2525 - 2528
(2007/10/03)
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- Cytotoxicity and antiestrogenicity of a novel series of basic diphenylethylenes
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On the premise that it is necessary to develop antiestrogens with a higher cytotoxic component in order to reduce the risks of the development of heterogeneous malignant cell populations in breast cancer, we studied a novel series of basic diphenylethylenes, for the most part devoid of estrogenic activity, with low antiestrogenicity but much enhanced cytotoxicity compared to the reference drug tamoxifen. The main structural features associated with cytotoxicity were E isomery, substituents of five to eight carbons on the ethylene bond, and dibasicity.
- Gilbert, Jacques,Fuentes, Maryse,Ojasoo, Tiiu,Doré, Jean-Christophe,Pons, Michel
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p. 1104 - 1111
(2007/10/03)
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- Tilt Angle Variation as a Function of Chain Length and Temperature in the Smectic C Phases of p,Alkoxyphenyl-p,Alkoxybenzoates
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The variation of the tilt angle with temperature in the smectic C phase has generally been shown to be non-existent or very slow for compounds or mixtures with the nematic-smectic C transition, while in the case of systems with the smectic A-smectic C transition, a relation between the steepness of this variation, near the transition, and the width of the smectic A domain has been observed.In this work, the variation of tilt angle in the smectic C phase is described for p-alkoxyphenyl-p-alkoxybenzoate homologous series, for which the evolution of polymorphism can be controlled systematically, by varying stepwise the length of the aliphatic chains, and for which large domains can be obtained for each type of phase sequence, nematic-, smectic A- and isotropic-smectic C.After completing the discussion made previously on the incidence of chain length on polymorphism, we confirm that the variation of tilt angle with temperature is slowest for compounds with intermediate chain lengths corresponding to the largest smectic A temperature range; this variation becomes continuously steeper when the smectic A domain becomes narrow.In addition, we show that the same description can be extended to the other types of phase sequences, by using the hypothesis of a virtual smectic A-smectic C transition above the observed nematic- or isotropic-smectic C transition.In fact, short chain lengths for homologues with a nematic/smectic C transition, or long chain lengths for homologues with an isotropic/smectic C transition, lead to an increase of the tilt angle at the phase transition and to a decrease of the amplitude of its variation with temperature; in our description, this behaviour corresponds to an increase of the temperature range between the real and virtual transitions.As a consequence, the homologues with very short and very long chain lengths show a quasi temperature-independent tilt angle, while the other homologues present a tilt angle variation similar to that observed for compounds exhibiting a smectic C/smectic A transition.This feature indicates that there is no need to distinguish between different types of smectic C phase.
- Heinrich, B.,Guillon, D.
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- Synthesis, Spectral Data and Extraction of Copper by 1-(2'-Hydroxy-5'-alkylphenyl)-1-alkanone Oximes
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1-(2'-Hydroxy-5'-alkylphenyl)-1-ethanone oximes with a normal alkyl group containing 2 to 12 carbon atoms and 1-(2'-hydroxy-5'-methylphenyl)-1-alkanone oximes containing 1 to 11 carbon atoms in the hydrocarbon chain were synthesized.Spectral data (u.v., i.r., n.m.r. and 13C) of oximes are reported.Four of these oximes were used for copper extraction from acidic solution.The results obtained indicate, that these oximes are better extractants than alkyl derivatives of 2-hydroxybenzophenone oximes.
- Krzyzanowska, Ewa,Olszanowski, A.,Juskowiak, M.
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p. 617 - 630
(2007/10/02)
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- RECHERCHES SUR LES SUBSTANCES MESOGENES-VIII; PREPARATION ET PROPERTIES MESOMORPHES DE SERIES ISOMETRIQUES
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The synthesis and the mesomorphic properties of various series of isometric mesogenic compounds are described.It is confirmed that isometric mesogenic molecules may be nematogenic and/or smectogenic according to the position of the polar rigid core.
- Malthete, Jacques,Canceill, Josette,Gabard, Jacqueline,Jacques, Jean
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p. 2815 - 2821
(2007/10/02)
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