- Solvolyses of naphthoyl chlorides. Solvent effect and Grunwald-Winstein correlation analyses with YxBnCl scales
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The solvolyses of 1-naphthoyl (2), 2-naphthoyl (3), 4-methyl-1-naphthoyl (4) and 6-methoxy-2-naphthoyl (5) chlorides in a variety of solvents were studied, and correlation analyses by using the single- and dual-parameter Grunwald-Winstein equations were examined. An excellent linear relationship (R = 0.995) for 4, log (k/k0) = 0.733YxBnCl + 0.269NOTs, was observed. An SN1-like mechanism with decreasing extent of nucleophilic solvent participation was found in the solvolysis of 2 and 4.2-Naphthoyl chloride is likely to have a mechanism at the borderline of SN1-like dissociation and an addition-elimination process. 6-Methoxy-2-naphthoyl chloride shows more SN1-like character than 3 and is associated with nucleophilic solvent intervention more pronounced than that for 2 and 4. The applicability and the advantages of using the YxBnCl scale for different types of substrates are discussed. Copyright
- Liu, Kwang-Ting,Hwang, Patty Y.-H.,Chen, Hun-I.
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- 4-Alkyl-1,2,4-triazole-3-thione analogues as metallo-β-lactamase inhibitors
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In Gram-negative bacteria, the major mechanism of resistance to β-lactam antibiotics is the production of one or several β-lactamases (BLs), including the highly worrying carbapenemases. Whereas inhibitors of these enzymes were recently marketed, they only target serine-carbapenemases (e.g. KPC-type), and no clinically useful inhibitor is available yet to neutralize the class of metallo-β-lactamases (MBLs). We are developing compounds based on the 1,2,4-triazole-3-thione scaffold, which binds to the di-zinc catalytic site of MBLs in an original fashion, and we previously reported its promising potential to yield broad-spectrum inhibitors. However, up to now only moderate antibiotic potentiation could be observed in microbiological assays and further exploration was needed to improve outer membrane penetration. Here, we synthesized and characterized a series of compounds possessing a diversely functionalized alkyl chain at the 4-position of the heterocycle. We found that the presence of a carboxylic group at the extremity of an alkyl chain yielded potent inhibitors of VIM-type enzymes with Ki values in the μM to sub-μM range, and that this alkyl chain had to be longer or equal to a propyl chain. This result confirmed the importance of a carboxylic function on the 4-substituent of 1,2,4-triazole-3-thione heterocycle. As observed in previous series, active compounds also preferentially contained phenyl, 2-hydroxy-5-methoxyphenyl, naphth-2-yl or m-biphenyl at position 5. However, none efficiently inhibited NDM-1 or IMP-1. Microbiological study on VIM-2-producing E. coli strains and on VIM-1/VIM-4-producing multidrug-resistant K. pneumoniae clinical isolates gave promising results, suggesting that the 1,2,4-triazole-3-thione scaffold worth continuing exploration to further improve penetration. Finally, docking experiments were performed to study the binding mode of alkanoic analogues in the active site of VIM-2.
- Gavara, Laurent,Legru, Alice,Verdirosa, Federica,Sevaille, Laurent,Nauton, Lionel,Corsica, Giuseppina,Mercuri, Paola Sandra,Sannio, Filomena,Feller, Georges,Coulon, Rémi,De Luca, Filomena,Cerboni, Giulia,Tanfoni, Silvia,Chelini, Giulia,Galleni, Moreno,Docquier, Jean-Denis,Hernandez, Jean-Fran?ois
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supporting information
(2021/06/15)
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- Synthesis method of beta-chloro acid ester and alpha, beta-unsaturated acid ester compound
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The invention belongs to the technical field of organic chemistry, and particularly relates to a synthesis method of beta-chloro acid ester and an alpha, beta-unsaturated acid ester compound. The structure of the compound is characterized by 1H NMR and 13C NMR and is confirmed. The method comprises the steps of by taking acetonitrile as a solvent, carrying out fragmentation on olefin, chlorooxalic acid monoester and 2, 6-dimethyl pyridine under a photocatalytic condition to generate an alkoxyacyl free radical intermediate, carrying out free radical addition reaction on the alkoxyacyl free radical intermediate and the olefin to generate carbon free radicals, then carrying out chlorination reaction to obtain the beta-chloro acid ester compound, and carrying out dehydrochlorination reaction under a DBU condition to generate the alpha, beta-unsaturated acid ester compound. The preparation method of the compound disclosed by the invention has the advantages of starting from olefin, being mild in condition, simple and efficient, strong in functional group compatibility and wide in substrate application range, and various beta-chloro acid ester and alpha, beta-unsaturated acid ester compounds can be synthesized from highly commercialized raw materials. On the basis of photoreaction of fluid chemistry, a target product can also be obtained with a relatively good yield, and the method has very good industrial and medicinal chemistry application values.
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Paragraph 0108-0112
(2021/08/11)
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- Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
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A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C-H bond, cleavage of inert C-C bond, and formation of C-O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
- Dong, Jianyu,Chen, Xiuling,Ji, Fangyan,Liu, Lixin,Su, Lebin,Mo, Min,Tang, Jian-Sheng,Zhou, Yongbo
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- 4-Amino-1,2,4-triazole-3-thione-derived Schiff bases as metallo-β-lactamase inhibitors
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Resistance to β-lactam antibiotics in Gram-negatives producing metallo-β-lactamases (MBLs) represents a major medical threat and there is an extremely urgent need to develop clinically useful inhibitors. We previously reported the original binding mode of 5-substituted-4-amino/H-1,2,4-triazole-3-thione compounds in the catalytic site of an MBL. Moreover, we showed that, although moderately potent, they represented a promising basis for the development of broad-spectrum MBL inhibitors. Here, we synthesized and characterized a large number of 4-amino-1,2,4-triazole-3-thione-derived Schiff bases. Compared to the previous series, the presence of an aryl moiety at position 4 afforded an average 10-fold increase in potency. Among 90 synthetic compounds, more than half inhibited at least one of the six tested MBLs (L1, VIM-4, VIM-2, NDM-1, IMP-1, CphA) with Ki values in the μM to sub-μM range. Several were broad-spectrum inhibitors, also inhibiting the most clinically relevant VIM-2 and NDM-1. Active compounds generally contained halogenated, bicyclic aryl or phenolic moieties at position 5, and one substituent among o-benzoic, 2,4-dihydroxyphenyl, p-benzyloxyphenyl or 3-(m-benzoyl)-phenyl at position 4. The crystallographic structure of VIM-2 in complex with an inhibitor showed the expected binding between the triazole-thione moiety and the dinuclear centre and also revealed a network of interactions involving Phe61, Tyr67, Trp87 and the conserved Asn233. Microbiological analysis suggested that the potentiation activity of the compounds was limited by poor outer membrane penetration or efflux. This was supported by the ability of one compound to restore the susceptibility of an NDM-1-producing E. coli clinical strain toward several β-lactams in the presence only of a sub-inhibitory concentration of colistin, a permeabilizing agent. Finally, some compounds were tested against the structurally similar di-zinc human glyoxalase II and found weaker inhibitors of the latter enzyme, thus showing a promising selectivity towards MBLs.
- Baud, Damien,Bebrone, Carine,Becker, Katja,Benvenuti, Manuela,Cerboni, Giulia,Chelini, Giulia,Cutolo, Giuliano,De Luca, Filomena,Docquier, Jean-Denis,Feller, Georges,Fischer, Marina,Galleni, Moreno,Gavara, Laurent,Gresh, Nohad,Kwapien, Karolina,Legru, Alice,Mangani, Stefano,Mercuri, Paola,Pozzi, Cecilia,Sannio, Filomena,Sevaille, Laurent,Tanfoni, Silvia,Verdirosa, Federica,Berthomieu, Dorothée,Bestgen, Beno?t,Frère, Jean-Marie,Hernandez, Jean-Fran?ois
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supporting information
(2020/09/16)
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- Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
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A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO 2 F 2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.
- Qin, Hua-Li,S Alharbi, Njud,Wang, Shi-Meng
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p. 3901 - 3907
(2019/10/11)
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- Intramolecular Tandem Seleno-Michael/Aldol Reaction: A Simple Route to Hydroxy Cyclo-1-ene-1-carboxylate Esters
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Intramolecular tandem seleno-Michael/aldol reaction followed by an oxidation-elimination process can be an efficient tool for the construction of hydroxy cyclo-1-ene-1-carboxylate esters from oxo-α,β-unsaturated esters. Generation of lithium selenolate from elemental selenium and n-BuLi provides a simple and efficient one-pot access to cyclic endo-Morita-Baylis-Hillman adducts.
- Banachowicz, Piotr,Mlynarski, Jacek,Buda, Szymon
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p. 11269 - 11277
(2018/09/06)
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- Facile, highly efficient and environmentally friendly transesterification mediated by platinum dioxide and nickel oxide under essentially neutral conditions
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A practical, facile and highly efficient transesterification reaction under essentially neutral conditions was achieved using platinum dioxide (PtO2) or PtO2/nickel oxide (NiO) as the catalyst. A number of esters and alcohols that contain various functional groups were employed. Good to excellent yields were obtained for different aromatic or aliphatic starting materials. The Pt-alcohol intermediate generated in situ facilitated the exchange of low-alcohol esters to high-alcohol esters.
- Teng, Binhao,Shi, Jiangong,Yao, Chunsuo
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supporting information
p. 2465 - 2471
(2018/06/11)
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- Ni-Catalyzed chemoselective alcoholysis of: N -acyloxazolidinones
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Although N-acyloxazolidinone-based (catalytic) asymmetric synthetic methodologies occupy an important position in modern organic synthesis, the catalytic cleavage of a chiral auxiliary remains underdeveloped. We report the Ni(cod)2/bipyr.-catalyzed alcoholysis of N-acyloxazolidinones to deliver esters. The reaction is broad in scope for both N-acyloxazolidinone substrates and alcohol nucleophiles, and displays good functional group tolerance and excellent chemoselectivity. A gram-scale methanolysis allowed the enantioselective synthesis of the C22-C26 segment of a close analogue of the potent immunosuppressant agent FK506.
- Huang, Pei-Qiang,Geng, Hui
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supporting information
p. 593 - 599
(2018/02/14)
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- Selective conversion of primary amides to esters promoted by KHSO4
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Primary amides, either aliphatic or aromatic, are easily converted to the corresponding esters via reflux in lower primary alcohols in the presence of KHSO4. Secondary amides lead to complicated mixtures under analogous conditions, whereastertiary amides were inert. Use of isopropyl alcohol resulted inthe formation of product atslower rate and lower yieldalong withside products, whereas, use of tertiary alcoholsdid not give successful conversion andallyl and benzyl alcohol provided complex mixtures.
- Sattenapally, Narsimha,Sharma, Jhanvi,Hou, Yuqing
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p. 174 - 183
(2018/09/10)
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- Fe-catalyzed esterification of amides via C-N bond activation
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An efficient Fe-catalyzed esterification of primary, secondary, and tertiary amides with various alcohols for the preparation of esters was performed. The esterification process was accomplished with FeCl3$6H2O, which is a stable, inexpensive, environmentally friendly catalyst with high functional group tolerance.
- Chen, Xiuling,Hu, Siying,Chen, Rongxing,Wang, Jian,Wu, Minghu,Guo, Haibin,Sun, Shaofa
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p. 4571 - 4576
(2018/02/09)
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- Continuous Flow Synthesis under High-Temperature/High-Pressure Conditions Using a Resistively Heated Flow Reactor
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A cheap, easy-to-build, and effective resistively heated reactor for continuous flow synthesis at high temperature and pressure is herein presented. The reactor is rapidly heated directly using an electric current and is capable of rapidly delivering temperatures and pressures up to 400 °C and 200 bar, respectively. High-temperature and high-pressure applications of this reactor were safely performed and demonstrated by selected transformations such as esterifications, transesterifications, and direct carboxylic acid to nitrile reactions using supercritical ethanol, methanol, and acetonitrile. Reaction temperatures were between 300 and 400 °C with excellent conversions and good to excellent isolated product yields. Examples of Diels-Alder reactions were also carried out at temperatures up to 300 °C in high yield. No additives or catalysts were used in the reactions.
- Adeyemi, Ahmed,Bergman, Joakim,Br?nalt, Jonas,S?vmarker, Jonas,Larhed, Mats
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supporting information
p. 947 - 955
(2017/07/26)
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- 1,2,4-Triazole-3-thione Compounds as Inhibitors of Dizinc Metallo-β-lactamases
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Metallo-β-lactamases (MBLs) cause resistance of Gram-negative bacteria to β-lactam antibiotics and are of serious concern, because they can inactivate the last-resort carbapenems and because MBL inhibitors of clinical value are still lacking. We previously identified the original binding mode of 4-amino-2,4-dihydro-5-(2-methylphenyl)-3H-1,2,4-triazole-3-thione (compound IIIA) within the dizinc active site of the L1 MBL. Herein we present the crystallographic structure of a complex of L1 with the corresponding non-amino compound IIIB (1,2-dihydro-5-(2-methylphenyl)-3H-1,2,4-triazole-3-thione). Unexpectedly, the binding mode of IIIB was similar but reverse to that of IIIA. The 3 D structures suggested that the triazole–thione scaffold was suitable to bind to the catalytic site of dizinc metalloenzymes. On the basis of these results, we synthesized 54 analogues of IIIA or IIIB. Nineteen showed IC50 values in the micromolar range toward at least one of five representative MBLs (i.e., L1, VIM-4, VIM-2, NDM-1, and IMP-1). Five of these exhibited a significant inhibition of at least four enzymes, including NDM-1, VIM-2, and IMP-1. Active compounds mainly featured either halogen or bulky bicyclic aryl substituents. Finally, some compounds were also tested on several microbial dinuclear zinc-dependent hydrolases belonging to the MBL-fold superfamily (i.e., endonucleases and glyoxalase II) to explore their activity toward structurally similar but functionally distinct enzymes. Whereas the bacterial tRNases were not inhibited, the best IC50 values toward plasmodial glyoxalase II were in the 10 μm range.
- Sevaille, Laurent,Gavara, Laurent,Bebrone, Carine,De Luca, Filomena,Nauton, Lionel,Achard, Maud,Mercuri, Paola,Tanfoni, Silvia,Borgianni, Luisa,Guyon, Carole,Lonjon, Pauline,Turan-Zitouni, Gülhan,Dzieciolowski, Julia,Becker, Katja,Bénard, Lionel,Condon, Ciaran,Maillard, Ludovic,Martinez, Jean,Frère, Jean-Marie,Dideberg, Otto,Galleni, Moreno,Docquier, Jean-Denis,Hernandez, Jean-Fran?ois
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p. 972 - 985
(2017/06/27)
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- Diethyloxalate as “CO” Source for Palladium-Catalyzed Ethoxycarbonylation of Bromo- and Chloroarene Derivatives
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Palladium(II)-catalyzed ethoxycarbonylation of aryl bromides with diethyloxalate oxalate is described. Functionalized aromatic esters can be efficiently synthesized with only 0.65 mol % PdCl2(PPh3)2 catalyst under microwav
- Monrose, Amandine,Salembier, Helori,Bousquet, Till,Pellegrini, Sylvain,Pélinski, Lydie
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supporting information
p. 2699 - 2704
(2017/08/16)
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- Synthesis of naphthalenecarboxylic and naphthalenedicarboxylic acids from naphthalene, carbon tetrachloride, and alcohols in the presence of iron catalysts
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Alkyl naphthalenecarboxylates and dialkyl naphthalenedicarboxylates have been synthesized by reactions of naphthalene and its derivatives with alcohols and carbon tetrachloride in the presence of iron catalysts.
- Baiguzina,Erokhina,Khusnutdinov
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p. 389 - 395
(2017/05/01)
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- Naphthyl-substituted pyridazine structure unit containing compounds and methods for their preparation and use
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The invention discloses compounds containing naphthyl substituted pyridazine structural unit, and a preparation method and application thereof. The structural general formula of the compounds containing naphthyl substituted pyridazine structural unit is disclosed as Formula I. The compounds disclosed as Formula I have proper nuclear magnetic detection; and in order to solve the problems of less research on near-infrared materials and deficiency in high-efficiency high-stability near-infrared luminescent materials at present stage, the invention provides a series of near-infrared luminescent materials containing naphthyl substituted pyridazine structure. The compounds have the advantages of accessible raw material, simple preparation process and high overall yield, and have important application value for researching development and application of near-infrared materials.
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Paragraph 0082-0084
(2016/10/27)
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- Synthesis of naphthalene ring derivatives and Benzoheterocycles the method of the compound
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The invention discloses a method for synthesizing naphthalene derivative and benzo-heterocycle compounds. The method is realized by promoting a reaction similar to Mortia-Baylis-Hillman between aryl aldehyde having alpha, beta-unsaturated ester on ortho-position and ketone compounds under the catalysis action of tertiary amine and tertiary phosphine organic small molecular catalysts, so as to remove a molecule of H2O, so that the naphthalene derivative or benzo-heterocycle compounds are generated. The method disclosed by the invention is simple in operation step, cheap and easily available in adopted catalysts and harmless to environment, and a series of naphthalene derivative and benzo-heterocycle compounds are synthesized with relatively high yield.
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Paragraph 0016; 0017; 0018; 0019; 0020
(2016/10/10)
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- Metal-free aerobic oxidative esterification of aldehydes in the presence of cyanide
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A metal-free aerobic oxidative esterification of aldehydes in the presence of cyanide is described. Various aromatic aldehydes and sterically congested alcohols were amenable to this protocol. In addition, this method could be extended to the preparation of thioesters with a thiol in place of an alcohol. Furthermore, the cyanide-mediated aerobic oxidation of aldehydes was applied to the synthesis of lactones via intramolecular esterification in the absence of an alcohol.
- Kim, Yoo-Jin,Cheon, Cheol-Hong
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supporting information
p. 2055 - 2061
(2015/08/18)
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- Iridium-catalyzed direct C-H amidation with weakly coordinating carbonyl directing groups under mild conditions
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An iridium-catalyzed direct C-H amidation of weakly coordinating substrates, in particular of those bearing ester and ketone groups, under very mild conditions has been developed. The observed high reaction efficiency was achieved by the combined use of acetic acid and lithium carbonate as additives. Copyright
- Kim, Jinwoo,Chang, Sukbok
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supporting information
p. 2203 - 2207
(2014/03/21)
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- Novel 1,3,4-oxadiazole thioether derivatives targeting thymidylate synthase as dual anticancer/antimicrobial agents
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A series of novel 1,3,4-oxadiazole thioether derivatives (compounds 9-44) were designed and synthesized as potential inhibitors of thymidylate synthase (TS) and as anticancer agents. The in vitro anticancer activities of these compounds were evaluated against three cancer cell lines by the MTT method. Among all the designed compounds, compound 18 bearing a nitro substituent exhibited more potent in vitro anticancer activities with IC50 values of 0.7 ± 0.2, 30.0 ± 1.2, 18.3 ± 1.4 μM, respectively, which was superior to the positive control. In the further study, it was identified as the most potent inhibitor against two kinds of TS protein (for human TS and Escherichia coli TS, IC50 values: 0.62 and 0.47 μM, respectively) in the TS inhibition assay in vitro and the most potent antibacterial agents with MIC (minimum inhibitory concentrations) of 1.56-3.13 μg/mL against the tested four bacterial strains. Molecular docking and 3D-QSAR study supported that compound 18 can be selected as dual antitumor/antibacterial candidate in the future study.
- Du, Qian-Ru,Li, Dong-Dong,Pi, Ya-Zhou,Li, Jing-Ran,Sun, Jian,Fang, Fei,Zhong, Wei-Qing,Gong, Hai-Bin,Zhu, Hai-Liang
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p. 2286 - 2297
(2013/05/09)
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- Adamantyl derivative as a potent inhibitor of plasmodium FK506 binding protein 35
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FKBP35, FK506 binding protein family member, in Plasmodium species displays a canonical peptidyl-prolyl isomerase (PPIase) activity and is intricately involved in the protein folding process. Inhibition of PfFKBP35 by FK506 or its analogues were shown to interfere with the in vitro growth of Plasmodium falciparum. In this study, we have synthesized adamantyl derivatives, Supradamal (SRA/4a) and its analogues SRA1/4b and SRA2/4c, which demonstrate submicromolar inhibition of Plasmodium falciparum FK506 binding domain 35 (FKBD35) PPIase activity. SRA and its analogues not only inhibit the in vitro growth of Plasmodium falciparum 3D7 strain but also show stage specific activity by inhibiting the trophozoite stage of the parasite. SRA/4a also inhibits the Plasmodium vivax FKBD35 PPIase activity and our crystal structure of PvFKBD35 in complex with the SRA provides structural insights in achieving selective inhibition against Plasmodium FKBPs.
- Harikishore, Amaravadhi,Leow, Min Li,Niang, Makhtar,Rajan, Sreekanth,Pasunooti, Kalyan Kumar,Preiser, Peter Rainer,Liu, Xuewei,Yoon, Ho Sup
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supporting information
p. 1097 - 1101
(2013/12/04)
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- One-pot transformation of carboxylic acids into nitriles
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A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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p. 5886 - 5892
(2013/09/23)
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- Design, synthesis, biological evaluation and molecular modeling of 1,3,4-oxadiazoline analogs of combretastatin-A4 as novel antitubulin agents
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A total of 20 novel 1,3,4-oxadiazoline analogs (6a-6t) of combretastatin A-4 with naphthalene ring were designed, synthesized, and evaluated for biological activities as potential tubulin polymerization inhibitors. Among these compounds, 6n showed the most potent antiproliferative activities against multiple cancer cell lines and retained the microtubule disrupting effects. Docking simulation was performed to insert compound 6n into the crystal structure of tubulin to determine the probable binding model. These results indicated oxadiazoline compounds bearing the naphthyl moiety are promising tubulin inhibitors.
- Hu, Yang,Lu, Xiang,Chen, Ke,Yan, Ru,Li, Qing-Shan,Zhu, Hai-Liang
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scheme or table
p. 903 - 909
(2012/03/10)
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- Design and synthesis of new (E)-cinnamic N-acylhydrazones as potent antitrypanosomal agents
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We report herein the synthesis and trypanocidal profile of new (E)-cinnamic N-acylhydrazones (NAHs) designed by exploiting molecular hybridization between the potent cruzain inhibitors (E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(4-bromophenyl) prop-2-en-1-one and (E)-3-hydroxy-N'-((2-hydroxynaphthalen-1-yl)methylene)-7- methoxy-2-naphthohydrazide. These derivatives were evaluated against both amastigote and trypomastigote forms of Trypanosoma cruzi and lead us to identify two compounds that were approximately two times more active than the reference drug, benznidazole, and with good cytotoxic index. Although designed as cruzain inhibitors, the weak potency displayed by the best cinnamyl NAH derivatives indicated that another mechanism of action was likely responsible for their trypanocide action.
- Carvalho, Samir A.,Feitosa, Larisse O.,Soares, Marcio,Costa, Thadeu E.M.M.,Henriques, Maria G.,Salomao, Kelly,De Castro, Solange L.,Kaiser, Marcel,Brun, Reto,Wardell, James L.,Wardell, Solange M.S.V.,Trossini, Gustavo H.G.,Andricopulo, Adriano D.,Da Silva, Edson F.,Fraga, Carlos A.M.
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experimental part
p. 512 - 521
(2012/09/07)
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- Phosphonium chloride as a non-volatile chlorinating reagent: Preparation and reaction in no solvent or ionic liquid
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Reaction of triphenylphosphine with trichloroisocyanuric acid in no solvent or an ionic liquid gave the corresponding phosphonium chloride, which can be used as a cheap and safe chlorinating reagent. Conversion of hydroxyheterocycles to chloroheterocycles, carboxylic acids to carboxylic acid chlorides, and primary amides to nitriles were accomplished by using the phosphonium chloride in excellent to good yields.
- Sugimoto, Osamu,Harada, Yukihiro,Tanji, Ken-Ichi
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p. 1583 - 1590
(2013/08/15)
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- Synthesis of naphthalenes via platinum-catalyzed hydroarylation of aryl enynes?
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An efficient synthetic method of functionalized naphthalenes having hydrogen, alkyl, alkenyl, aryl, or heteroaryl groups on the 4-position and ethoxycarbonyl group on the 2-position was developed through selective Pt-catalyzed 6-endo intramolecular hydroa
- Kang, Dongjin,Kim, Jinsik,Oh, Susung,Lee, Phil Ho
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p. 5636 - 5639
(2013/01/15)
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- Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
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Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
- Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 4701 - 4709
(2012/07/28)
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- Dual Bronsted acid/nucleophilic activation of carbonylimidazole derivatives
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Carbonylimidazole derivatives have been found to be highly active acylation reagents for esterification and amidation in the presence of pyridinium salts. These reactions are thought to involve both Bronsted acid and nucleophilic catalysis. This mode of activation has been applied to the synthesis of difficult to access oxazolidinones, as well as esters and amides. Finally, the use of pyridinium salts has been shown to accelerate the esterification of carboxylic acids with imidazole carbamates.
- Heller, Stephen T.,Fu, Tingting,Sarpong, Richmond
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supporting information; experimental part
p. 1970 - 1973
(2012/06/01)
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- Oxidative cross-esterification of dithiolanes with alcohols through a cross-dehydrogenative coupling (CDC)/deprotection sequence
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An unprecedented oxidative cross-esterification in an equimolar mixture of dithiolanes, alcohols and water through a CDC/deprotection sequence has been developed. The reaction itself features simple experimental procedures under very mild conditions and offers a new strategic protocol for the direct and efficient synthesis of structurally diverse esters.
- Fu, Liang,Yao, Chang-Jiang,Chang, Ning-Jie,Chen, Jia-Rong,Lu, Liang-Qiu,Xiao, Wen-Jing
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p. 506 - 508
(2012/01/15)
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- A clean, palladium-catalyzed oxidative esterification of aldehydes using benzyl chloride
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A highly efficient, mild, simple and clean procedure is presented for the one-pot oxidation of aromatic and aliphatic aldehydes to their corresponding ethyl esters using benzyl chloride as the oxidant under palladium-catalyzed conditions. The reaction is complete in just 30 min under microwave irradiation and inert conditions are not required to obtain good to excellent yields (65-93%) of isolated products.
- Heropoulos, Georgios A.,Villalonga-Barber, Carolina
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experimental part
p. 5319 - 5322
(2011/10/31)
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- The geometry and absorption of diketo-pyrrolo-pyrroles substituted with various aryls
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A series of five symmetrical and four unsymmetrical diaryl substituted diketo-pyrrolo-pyrroles was synthesized; two unsymmetrical derivatives are reported for the first time. The relationship between the theoretical excitation energies of the S0?→?S1 transition, computed by time dependent density functional theory and the experimental positions of 0-0 vibronic bands in the visible absorption (or fluorescence excitation) spectra was studied. Experimental data were obtained from either solution or from low temperature organic solvent glass, in which the progressions of the vibrational structure enabled correct assignment of vibronic sub-bands in some cases. Theoretical calculations predicted that a linear bathochromic and hyperchromic shift would accompany substitution of each phenyl in the parent 3,6-diphenyl-2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione by providing a more extensively conjugated aryl centre (2-naphthyl, biphenyl, stilbenyl) for the ensuing planar derivatives. Qualitatively, the experimental bathochromic shifts of the 0-0 vibronic sub-bands were in exact agreement with theory, whilst hyperchromic shifts were affected by the very low solubility of the planar, symmetrical derivatives. Deviations from this ideal behaviour were observed for non-planar derivatives (aryl?=?stilbenyl or 1-naphthyl), for which the dihedral angles describing the aryl, out-of-plane torsions were probably underestimated by DFT.
- Luňák Jr., Stanislav,Havel, Luká?,Vyňuchal, Jan,Horáková, Petra,Ku?erík, Ji?í,Weiter, Martin,Hrdina, Radim
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experimental part
p. 27 - 36
(2010/10/21)
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- Gold catalysis: In situ EXAFS study of homogeneous oxidative esterification
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Gold complexes were prepared and investigated as catalysts for the oxidative esterification of aldehydes. Stabilisation by pyridine ligands gave good conversions and the in situ extended X-ray absorption fine structure (EXAFS) study of the reactions indicated that the reaction mixtures contained only mononuclear gold species. Thus, this is the first proof for a homogeneous gold-catalysed oxidation reaction ; the presence of nanoparticles could be excluded experimentally.
- Hashmi, A. Stephen K.,Lothschuetz, Christian,Ackermann, Martin,Doepp, Rene,Anantharaman, Sankaran,Marchetti, Benjamin,Bertagnolli, Helmut,Rominger, Frank
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experimental part
p. 8012 - 8019
(2010/09/11)
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- Platinum-catalyzed intramolecular hydroarylation of allenyl arenes: Efficient synthesis of 1,4-dihydronaphthalenes
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An efficient synthetic method of 1,4-dihydronaphthalenes having various alkyl groups on the 4-position and/or ethoxycarbonyl group on the 2-position through selective intramolecular Pt-catalyzed 6-endo cyclohydroarylation of ethyl 2-benzyl-2,3-alkadienoat
- Mo, Juntae,Lee, Phil Ho
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scheme or table
p. 2570 - 2573
(2010/08/22)
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- Novel 4H-1,3,4-oxadiazin-5(6H)-ones with hydrophobic and long alkyl chains: Design, synthesis, and bioactive diversity on inhibition of monoamine oxidase, chitin biosynthesis and tumor cell
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A new series of nitrogen-containing heterocycles 4H-1,3,4-oxadiazin-5(6H)-ones derivatives with hydrophobic and long chains were designed and synthesized by direct cyclization reaction of N′-alkylation substituted aroylhydrazines with chloroacetyl chloride. The preliminary assays showed that some of the compounds displayed moderate to good inhibitory activities toward monoamine oxidase (MAO) at the concentration of 10-5-10-3 M, and antitumor activities against human lung cancer A-549 and human prostate cancer PC-3 cell lines at μM level, which might provide new scaffold for anticancer agents. Furthermore, compounds 5i and 5m exhibited significant inhibitory activity on chitin biosynthesis, which might represent a novel class of highly potential inhibitors of chitin synthesis. Crown Copyright
- Ke, Shao-Yong,Qian, Xu-Hong,Liu, Feng-Yi,Wang, Ni,Yang, Qing,Li, Zhong
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scheme or table
p. 2113 - 2121
(2009/10/02)
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- 1,3,4-Oxadiazoline derivatives as novel potential inhibitors targeting chitin biosynthesis: Design, synthesis and biological evaluation
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Two series of 1,3,4-oxadiazoline heterocycle derivatives were designed, synthesized and identified. Bioactivity assays showed that all synthesized compounds inhibited chitin synthesis in yeast, suggesting they might be a novel class of potential inhibitors against chitin biosynthesis. The structure-activity relationships (SAR) of these compounds are discussed.
- Ke, Shaoyong,Liu, Fengyi,Wang, Ni,Yang, Qing,Qian, Xuhong
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scheme or table
p. 332 - 335
(2011/02/26)
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- PROCESS
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A process for the alkoxyalkylation of an unsubstituted aromatic substrate or a substituted aromatic substrate, said substitution being via a carbon-carbon bond, said process comprising reacting the aromatic substrate with a dialkoxyalkane in the presence of a catalyst.
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- Highly efficient formation of halodiazoacetates and their use in stereoselective synthesis of halocyclopropanes
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Halogenated analogues of ethyl diazoacetate are synthesised by a novel and highly efficient procedure and give halocyclopropanes in good to excellent yields when exposed to a Rh(ii) catalyst in the presence of alkenes. The Royal Society of Chemistry 2008.
- Bonge, Hanne Therese,Pintea, Benjamin,Hansen, Tore
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body text
p. 3670 - 3672
(2009/02/05)
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- Direct conversion of aromatic ketones to arenecarboxylic esters via carbon-carbon bond-cleavage reactions
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Aromatic methyl ketones, ss-keto esters, and trifluoromethyl-l,3- diketones can be directly converted to arene-carboxylic esters via carbon-carbon bond cleavage of pyridinium iodide intermediates in the presence of copper(II) oxide, iodine, pyridine, and potassium carbonate in alcoholic media. The advantages of the present method in terms of good yields, mild reaction conditions, and inexpensive reagents should make this protocol a valuable alternative to the existing methods.
- Yin, Guodong,Gao, Meng,Wang, Zihua,Wu, Yandong,Wu, Anxin
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experimental part
p. 369 - 372
(2009/04/07)
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- Palladium-catalyzed oxidative carbonylation of alkyl and aryl indium reagents with CO under mild conditions
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CO now can react with organoindium reagents. A novel palladium-catalyzed oxidative carbonylation reaction of organoindium reagents by CO gas with desyl chloride as oxidant was developed in supplementation with the classical methods for preparation of carboxylic acid derivatives. Primary, secondary alkyl indium reagents with β-hydrogens and aryl indium reagents were suitable substrates, and the reaction could be carried out at 60°C under 50 psi CO. Carbonylation of alkyl indium reagents can occur smoothly without additional base. Although the indium reagents were prepared from corresponding Grignard reagents (at low temperature), they displayed full compatibility with various functional groups under the protic reaction conditions. Preliminary mechanistic studies including stoichiometric and catalytic reaction examination provided evidence to support the operation of the mechanism consisted of oxidative addition of deslyl chloride to Pd(0) and quick tautomerization to give a palladium enolate species II (ROPdCl), displacement of the enolate group in II by R2OH, followed by CO insertion to give alkoxycarbonyl palladium complex V, which undergoes transmetalation with R13ln and reductive elimination to afford the product and a Pd(0) species. In this mechanism, the alkoxycarbonyl group was transferred to the palladium center prior to the alkyl group, different from traditional ways initiated from oxidative addition of alkyl halides to a Pd(0) species.
- Zhao, Yingsheng,Jin, Liqun,Li, Peng,Lei, Aiwen
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supporting information; body text
p. 9429 - 9433
(2009/02/03)
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- A new manifold for the Morita reaction: Diene synthesis from simple aldehydes and acrylates/acrylonitrile mediated by phosphines
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Dienes have been formed with good stereoselectivity and in good yield from simple aldehydes and acrylates/acrylonitrile in the presence of a phosphine and a Lewis acid through a modification of the Morita reaction. The Royal Society of Chemistry.
- Palmelund, Anders,Myers, Eddie L.,Tai, Lik Ren,Tisserand, Steve,Butts, Craig P.,Aggarwal, Varinder K.
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p. 4128 - 4130
(2008/09/16)
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- Formation of arenes via diallylarenes: Strategic utilization of Suzuki-Miyaura cross-coupling, Claisen rearrangement and ring-closing metathesis
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Two new synthetic strategies for benzoannulation are reported. The first strategy is based on the Suzuki-Miyaura cross-coupling reaction. To this end, various ortho-diallylbenzene derivatives were prepared from the corrresponding diiodo derivatives by an allylation strategy using an allylboronate as coupling partner. These diallyl derivatives were subjected to a ring-closing metathesis (RCM) and one-pot dichlorodicyanoquinone (DDQ) oxidation sequence to deliver 2-substituted naphthalenes. In the second strategy, a double Claisen rearrangement and RCM protocol have been used as key steps to give highly functionalized benzoannulated quinone derivatives.
- Kotha, Sambasivarao,Shah, Vrajesh R.,Mandal, Kalyaneswar
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p. 1159 - 1172
(2008/04/03)
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- PROCESS
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A process for the alkoxyalkylation of an unsubstituted aromatic substrate or a substituted aromatic substrate, said substitution being via a carbon-carbon bond, said process comprising reacting the aromatic substrate with a dialkoxyalkane in the presence of a catalyst.
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Page/Page column 15
(2008/06/13)
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- Lewis acid-catalyzed benzannulation via unprecedented [4+2] cycloaddition of o-alkynyl(oxo)benzenes and enynals with alkynes
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The reaction of o-alkynyl(oxo)benzenes 1 with alkynes 2 in the presence of a catalytic amount of AuCl3 in (CH2Cl)2 at 80 °C gave the [4+2] benzannulation products, naphthyl ketone derivatives 3 and 4, in high yields. When the reaction was carried out using AuBr3 instead of AuCl3, the reaction speed was enhanced and the chemical yield was increased. On the other hand, when the reaction was carried out in the presence of a catalytic amount of Cu(OTf)2 and 1 equiv of a Bronsted acid, such as CF2HCO2H, in (CH 2Cl)2 at 100 °C, the decarbonylated naphthalene products 5 were obtained in high yields. Similarly, the Cu(OTf) 2-H2O-promoted reaction of the enynals 7 with an alkyne 2 afforded the corresponding [4+2] benzannulation products, decarbonylated benzene derivatives 8, in good yields. Both AuX3- and Cu(OTf) 2-catalyzed benzannulations proceed most probably through the formation of the benzo[c]pyrylium ate complex 10, the Diels-Alder addition of alkynes 2 to the ate complex, and the resulting bicyclic pyrylium ion intermediate 12. The mechanistic difference between the AuX3 and Cu(OTf)2-HA system is discussed.
- Asao, Naoki,Nogami, Tsutomu,Lee, Sunyoung,Yamamoto, Yoshinori
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p. 10921 - 10925
(2007/10/03)
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- Microwave promoted facile synthesis of methyl and ethyl carboxylates
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Microwave irradiation of carboxylic acids with trialkyl orthoacetate in solvent-free conditions afforded an efficient method for alkylation of carboxylic acids to corresponding alkyl carboxylates.
- Lee, Jong Chan,Song, In-Goul,Park, Jin Young
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p. 2209 - 2213
(2007/10/03)
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- Photosensitive compound
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Photosensitive compounds having preferably a functional group such as --SO2 Cl, --SO3 H, --SO3 R, STR1 (R, R', R" being alkyl) on a terminal benzene or naphthalene ring connected via a methylene group and STR2 moiety are improved in sensitivity to light and thermal stability, and thus useful in a photo resist.
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- Synthesis of ortho-Acylbenzylboronates via Cross-Coupling Reaction of (Dialkoxyboryl)methylzinc Reagents with Haloarenes. A Stable ortho-Quinodimethane Precursor
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The cross-coupling reaction of IZnCH2B(OCMe2)2 with iodoarenes in the presence of PdCl2(PPh3)2 produces the corresponding benzylic boronates in high yields.Among them, the benzylic boronates having an acyl group at the ortho position readily undergo the 1,5-rearrangement to the carbonyl oxygen producing the o-quinodimethane derivatives under thermal or photochemical conditions.The reaction provides benzo-fused cycloalkanes by trapping with dienophiles.cross
- Kanai, Gen,Miyaura, Norio,Suzuki, Akira
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p. 845 - 848
(2007/10/02)
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- Metal Arene Complexes in Organic Synthesis. Hydroxylation, Trimethylsilylation, and Carbethoxylation of Some Polycyclic Aromatic Hydrocarbons Utilizing η6-Arene-Chromium Tricarbonyl Complexes
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The deprotonation of polycyclic aromatic hydrocarbon (PAH) chromium tricarbonyl complexes (PAH = naphthalene, anthracene, phenanthrene, pyrene, fluoranthene) using an in situ technique where the PAH complex, the base (LiTMP or LDA), and the electrophile (trialkyl borate, trimethylsilyl chloride, or ethyl chloroformate) were placed in solution simultaneously resulted in hydroxylation, trimethylsilylation, or carbethoxylation of the PAH after oxidative workup where the regiochemistry was controlled by steric factors.As a result, substitution at positions of the PAHs not readily available by electrophilic substitution were obtained in some cases.Conditions minimizing isomer mixtures and factors affecting the regiochemistry and the scope of the reaction sequence were examined.
- Morley, James A.,Woolsey, Neil F.
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p. 6487 - 6495
(2007/10/02)
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- o-Quinodimethane Generation from α,α'-Dihalo-o-xylenes by Use of Sodium Benzenetellurolate
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Treatment of α,α'-dihalo-o-xylenes with sodium benzenetellurolate gave o-quinodimethane which readily reacted with dienophiles leading to Diels-Alder adducts.The best yields were obtained when the reaction was carried out in refluxing ethanol using two molar equivalents of the benzenetellurolate to α,α'-dihalo-o-xylenes.This reaction competes with substitution of the halogen atoms with the benzenetellurolate anion to afford α,α'-bis(phenyltelluro)-o-xylene, which did not give o-quinodimethane under identical conditions.It is likely that the reaction proceeds through nucleophilic attack of benzenetellurolate anion at the tellurium atom of α-halo-α'-phenyltelluro-o-xylene which is formed in situ by the substitution of one of the halogen atoms of the starting α,α'-dihalo-o-xylene with the benzenetellurolate anion.When sodium benzeneselenolate was employed, no evidence of o-quinodimethane formation was observed under similar conditions.
- Kambe, Nobuaki,Tsukamoto, Takashi,Miyoshi, Noritaka,Murai, Shinji,Sonoda, Noboru
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p. 3013 - 3018
(2007/10/02)
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- Desulfurization and Carbonylation of Mercaptans
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The first examples of the carbonylation of mercaptans are described: cobalt carbonyl catalyzes the desulfurization and carbonylation of mercaptans to carboxylic esters by means of carbon monoxide in aqueous alcohol.
- Shim, Sang Chul,Antebi, Shlomo,Alper, Howard
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p. 147 - 149
(2007/10/02)
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