- A scalable and green one-minute synthesis of substituted phenols
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A mild, green and highly efficient protocol was developed for the synthesis of substituted phenols via ipso-hydroxylation of arylboronic acids in ethanol. The method utilizes the combination of aqueous hydrogen peroxide as the oxidant and H2O2/HBr as the reagent under unprecedentedly simple and convenient conditions. A wide range of arylboronic acids were smoothly transformed into substituted phenols in very good to excellent yields without chromatographic purification. The reaction is scalable up to at least 5 grams at room temperature with one-minute reaction time and can be combined in a one-pot sequence with bromination and Pd-catalyzed cross-coupling to generate more diverse, highly substituted phenols.
- Elumalai, Vijayaragavan,Hansen, J?rn H.
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p. 40582 - 40587
(2020/11/18)
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- Magnesium tetrapyrazinoporphyrazines: Tuning of the pKa of red-fluorescent pH indicators
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Magnesium(ii) tetrapyrazinoporphyrazines (TPyzPzs) are excellent red fluorophores (λF ～ 663 nm, ΦF ～ 0.53 in THF). In this work, a series of magnesium(ii) complexes of unsymmetrical TPyzPzs bearing one or two phenol substituents was prepared. Suitable substitutions on the phenolic moiety tuned its pKa in the range of 5.5 to 13. Deprotonation of the phenolic group at higher pH induced a strong donor (phenolate) in the macrocycle that led to pH-dependent quenching of the red fluorescence of these indicators. pH sensing was proved in water solutions after the incorporation of TPyzPzs into two delivery systems-microemulsions and liposomes. The latter also serves as a simple model of biomembranes. Finally, a wavelength-ratiometric probe was constructed by the incorporation of a TPyzPz indicator and lipophilic pH-nonsensitive BODIPY dye into liposomes. Synthetic precursors for TPyzPzs, substituted pyrazine-2,3-dicarbonitriles, also represent donor-acceptor systems and the pH-dependent changes in absorption spectra may be easily visible to the naked eye.
- Karlikova, Martina,Cermakova, Veronika,Demuth, Jiri,Valer, Vojtech,Miletin, Miroslav,Novakova, Veronika,Zimcik, Petr
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supporting information
p. 6162 - 6173
(2019/05/16)
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- Synthesis and antibacterial activities of cadiolides A, B and C and analogues
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The one-pot multicomponent synthesis of natural butenolides named cadiolides A, B, C and analogues has been realized. The antibacterial structure activity relationship shows that the presence of phenolic hydroxyl groups and the number and position of bromine atoms on the different aromatic rings are important features for antibacterial activity, besides it was demonstrated the tolerance of both benzene and furan ring at position 3 of the butenolide nucleus. Furthermore, none of the most relevant antibacterial compounds showed any cytotoxicity in freshly isolated human neutrophils.
- Boulangé, Agathe,Parraga, Javier,Galán, Abraham,Cabedo, Nuria,Leleu, Stéphane,Sanz, Maria Jesus,Cortes, Diego,Franck, Xavier
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p. 3618 - 3628
(2015/07/27)
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- An eco-friendly Co(OAc)2-catalyzed aerobic oxidation of 4-benzylphenols into 4-hydroxybenzophenones
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An undecorated Co(OAc)2-catalyzed aerobic oxidation system has been reported that enables direct transformation of 4-benzylphenols into the corresponding 4-hydroxybenzophenones. The procedure is especially suitable for electron-withdrawing group-containing substrates, which are commonly inefficient to conduct this category of oxidation. Based on well-defined p-benzoquinone methides and the confirmed ethereal intermediate, a plausible mechanism was depicted.
- Huang, Jian-Gang,Guo, Ying,Jiang, Jian-An,Liu, Hong-Wei,Ji, Ya-Fei
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p. 7115 - 7124
(2015/02/19)
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- Cu(OAc)2-catalyzed remote benzylic C(sp3)-H oxyfunctionalization for C=O formation directed by the hindered para-hydroxyl group with ambient air as the terminal oxidant under ligand- and additive-free conditions
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A hindered para-hydroxyl group-directed remote benzylic C(sp3)-H oxyfunctionalization has been developed for the straightforward transformation of 2,6-disubstituted 4-cresols, 4-alkylphenols, 4-hydroxybenzyl alcohols and 4-hydroxybenzyl alkyl ethers into various aromatic carbonyl compounds. The ligand- and additive-free Cu(OAc)2-catalyzed atmospheric oxidation mediated by ethylene glycol unlocks a facile, atom-economical, and environmentally benign C=O formation for the functionalization of primary and secondary benzyl groups. Due to the pharmaceutical importance of 4-hydroxybenzaldehydes and 4-hydroxyphenones, the methodology is expected to be of significant value for both fundamental research and practical applications.
- Jiang, Jian-An,Chen, Cheng,Huang, Jian-Gang,Liu, Hong-Wei,Cao, Song,Ji, Ya-Fei
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supporting information
p. 1248 - 1254
(2014/03/21)
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- Total synthesis and biological activity of marine alkaloid eudistomins Y1-Y7 and their analogues
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Eudistomin Y class compounds are a series of β-carbolines which was originally isolated from a marine turnicate or ascidian near the South Korea Sea. These compounds contain bromo-substituted groups, which is one of the typical characters of marine natural products. We report herein the chemical synthesis and biological evaluation of seven new β-carboline-based metabolites, Eudistomins Y1-Y7, and their hydroxyl-methylated phenyl derivatives. Using bromo-substituted tryptamines and bromo-substituted phenylglyoxals as the key intermediates, Eudistomins Y 1-Y7 and their derivatives were synthesized via the acid-catalyzed Pictet-Spengler reaction and fully characterized by 1H- and 13C-NMR and mass spectroscopy. Biological studies revealed that all of the compounds showed moderate growth inhibitory activity against breast carcinoma cell line MDA-231 with IC50 of 15-63 μM and the inhibitory activities of hydroxyl-methylated phenyl products were higher than that of the corresponding natural products Eudistomins Y 1-Y7.
- Jin, Huijuan,Zhang, Puyong,Bijian, Krikor,Ren, Sumei,Wan, Shengbiao,Alaoui-Jamali, Moulay A.,Jiang, Tao
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p. 1427 - 1439
(2013/07/11)
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- Synthesis and SAR studies of marine natural products ma'edamines A, B and their analogues
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The synthesis of several analogues of ma'edamines A and B are reported. The synthesized compounds were tested on hormone receptor positive and HER2 positive breast cancer cell lines, by MTT assay. MED-114, 115, 117, 119, 120, 124, 128 and 131 were found to be equally active as Lapatinib on HER2 +ve cell line SKBR3.
- Saha, Sanjay,Reddy, Ch. Venkata Ramana,Xu, Shili,Sankar, Saranya,Neamati, Nouri,Patro, Balaram
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p. 5135 - 5139
(2013/09/12)
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- The first total synthesis and biological evaluation of marine natural products ma'edamines A and B
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We have developed the first total syntheses of marine natural products ma'edamines A (18) and B (20). Structurally, they contain a pyrazine-2-(1H)-one core and were screened for antiproliferative activity on several cancer cell lines. Out of the six cell lines tested, ma'edamines A and B showed significant cytotoxicity against human colon cancer line COLO 205 (IC50 7.9 and 10.3 μM, respectively), breast cancer cell line MCF-7 (IC50: 6.9 and 10.5 μM, respectively) and human lung adenocarcinoma cell line A549 (IC50: 12.2 and 15.4 μM, respectively). The apoptotic effect of ma'edamines was confirmed by comet assay. Hence ma'edamines are likely to be useful as leads for development of a new class of anti-cancer agents.
- Saha, Sanjay,Venkata Ramana Reddy, Ch.,Chiranjeevi,Addepally, Uma,Chinta Rao,Patro, Balaram
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p. 1013 - 1016
(2013/03/13)
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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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experimental part
p. 604 - 610
(2012/08/28)
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- Synthesis and biological evaluation of some 3,5-dibromo-4-hydroxy enoness
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Enones having an a,b-unsaturated carbonyl systems are important as Michael acceptors and constitute an important class of biologically active compounds. Enones are one of the most versatile synthons for various chemical transformations leading to the synthesis of several biodynamic heterocyclic compounds. Therefore, the chemistry of synthetic enones is most dynamic and challenging area embracing a vast spectrum of advances of both theoretical and practical relevance. In view of this, in the present paper synthesis of some 3,5-dibromo- 4-hydroxyphenyl enones are reported along with their herbicidal, fungicidal, insecticidal, animal health and antibacterial activities. Some of the compounds showed promising biological activities.
- Kothari, Seema
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p. 5927 - 5929
(2013/01/15)
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- Studies towards the synthesis of 13C-labelled anthocyanins
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The anthocyanins are a class of polyphenols found in nature, which are widely distributed throughout the plant kingdom and are thought to possess antioxidant properties. Methodology previously developed in our group for the regioselective placement of 13C-atoms into aromatic rings is being applied to the synthesis of 13C-labelled anthocyanins-namely cyanidin-3-glucoside and delphinidin-3-glucoside. Copyright
- Marshall, Laura J.,Cable, Karl M.,Botting, Nigel P.
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scheme or table
p. 315 - 318
(2011/05/02)
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- The first total synthesis of racemic Hydroxymoloka'iamine
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The first total synthesis of racemic hydroxymoloka'iamine, a new brominated metabolite isolated from Red Sea sponge Pseudoceratna arabica, was achieved in a high-yield reaction sequence.
- Ullah, Nisar
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experimental part
p. 879 - 882
(2009/12/01)
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- Thienopyridones as AMPK activators for the treatment of diabetes and obesity
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The present invention relates to compounds that activate AMP-activated protein kinase (AMPK), including the preparation of the compounds, compositions containing the compounds and the use of the compounds in the prevention or treatment of disorders such as diabetes, metabolic syndrome, and obesity.
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Page/Page column 68
(2010/02/10)
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- An intriguing effect of lithium perchlorate dispersed on silica gel in the bromination of aromatic compounds by N-bromosuccinimide
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A convenient and efficient procedure for electrophilic aromatic bromination has been developed by mixing of N-bromosuccinimide and an aromatic compound at room temperature on the surface of silica gel mixed with solid anhydrous LiClO4. All of the substrates examined underwent clean electrophilic aromatic bromination in reaction times of a few minutes to afford the corresponding bromoarenes under neutral conditions in excellent yield. In the case of thiophenol, no substitution reaction occurred, and the corresponding disulfide was obtained in excellent yield.
- Bagheri, Mojtaba,Azizi, Najmedin,Saidi, Mohammad R.
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p. 146 - 149
(2007/10/03)
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- Regioselective and high-yielding bromination of aromatic compounds using hexamethylenetetramine-bromine
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A regioselective and highly efficient method for bromination of aromatic compounds in the presence of a stoichiometric amount of hexamethylenetetramine- bromine (HMTAB) as an efficient reagent in dichloromethane is reported. The selectivity depends on the temperature and nature of the substituent on the substrate. The reactivity of this reagent was increased by supporting it to silica gel for bromination of less activated compounds.
- Heravi, Majid M.,Abdolhosseini, Nafiseh,Oskooie, Hossein A.
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p. 8959 - 8963
(2007/10/03)
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- Pyridinium bromochromate: A new and efficient reagent for bromination of hydroxy aromatics
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Pyridinium bromochromate (PBC) has been used as an efficient and selective nuclear brominating agent for bromination of various substituted hydroxy-acetophenones, aldehydes and phenols.
- Patwari, Shivaji B.,Baseer, Mohammad A.,Vibhute, Yashwant B.,Bhusare, Sudhakar R.
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p. 4893 - 4894
(2007/10/03)
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- Interesting product formation during O-alkylation and subsequent rearrangement of two building blocks of dibromotyrosine based natural products
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The O-alkylation (allylation/propargylation) of 3,5-dibromo-4-hydroxybenzaldehyde 1 and the corresponding acetophenone 2 results in the formation of aryl-aryl coupled product by loss of formyl groups, aryl-aryl ether and aryloxy acetone in addition to the expected O-allyl / propargyl ethers. While the thermal Claisen rearrangement of allyl ethers 1 and 2 furnishes the C-allyl products by loss of bromine, the propargyl ether 7 surprisingly resisted rearrangement and underwent oxidation to yield the corresponding carboxylic acid.
- Mallavadhani, Uppuluri V.,Mahapatra, Anita,Narasimhan,Sahoo
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p. 1460 - 1466
(2007/10/03)
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- Solid state nuclear bromination with N-bromosuccinimide. Part 1. Experimental and theoretical studies on some substituted aniline, phenol and nitro aromatic compounds
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Solid state bromination of a number of substituted phenol, aniline and nitro aromatic compounds with N-bromosuccinimide yields exclusively the nuclear brominated products. Reactivity in the solid state depends on the reaction time, temperature and nature of the substituent on the substrate. The reaction apparently proceeds by an electrophilic aromatic substitution pathway. Molecular orbital and reaction free energy calculations also support such a view. Thermal analysis and video microscopic observation reveal the nature of the solid state reaction. Crystallinity is required for the reactivity and product selectivity. Product yield decreases with loss of selectivity when the reaction is carried out in a melt or in solution. Unlike the topochemical solid state reactions wherein molecular packing is more important than the intrinsic reactivity, these reactions demonstrate the importance of both these factors.
- Sarma, Jagarlapudi A.R.P.,Nagaraju, Akula
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p. 1113 - 1118
(2007/10/03)
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- Process for the production of 3-mono or 3,5 dihalogenated 4-acetoxystyrene, its polymerization, and hydrolysis
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The present invention relates to a process for the production of 3-mono or 3,5-disubstituted-4-acetoxystyrene wherein the 3- or 3,5-substitution is independently C1 to C10 alkyl, chlorine, bromine, iodine, --NO2, --NH2, or --SO3 H, a process for its polymerization, hydrolysis, and use in a variety of compositions.
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- Substituted alkylaryl ketones and methods of use as herbicides
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Ring and side chain substituted alkylaryl ketones are useful in controlling the growth of germinating and seedling weed grasses and germinating and seedling broadleaf weeds.
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