- Intramolecular Cyclization of Vinyldiazoacetates as a Versatile Route to Substituted Pyrazoles
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Vinyldiazo compounds undergo a thermal electrocyclization to form pyrazoles in yields of up to 95percent. The reactions are operationally simple, use readily available starting materials, require no intervention of a catalyst, and enable the synthesis of mono-, di- A nd tri-substituted pyrazoles. With the ability to produce highly substituted pyrazoles and the flexibility in installing various types of substituents, this method constitutes a new entry to this valuable heterocyclic scaffold and may be of interest to all branches of the chemical industry.
- Drikermann, Denis,G?rls, Helmar,Kerndl, Valerie,Vilotijevic, Ivan
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supporting information
p. 1158 - 1162
(2020/07/20)
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- Modular 1,1′-Ferrocenediyl-cored P-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
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A novel ferrocene-based P-stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β-unsubstituted or -substituted itaconates and α-methylene-γ-oxo-carboxylates. (Figure presented.).
- Poklukar, Ga?per,Stephan, Michel,Mohar, Barbara
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p. 2566 - 2570
(2018/05/16)
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- Evaluation of a series of 2-napthamide derivatives as inhibitors of the drug efflux pump AcrB for the reversal of antimicrobial resistance
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Drug efflux pumps confer multidrug resistance to dangerous pathogens which makes these pumps important drug targets. We have synthesised a novel series of compounds based on a 2-naphthamide pharmacore aimed at inhibiting the efflux pumps from Gram-negativ
- Wang, Yinhu,Mowla, Rumana,Guo, Liwei,Ogunniyi, Abiodun D.,Rahman, Taufiq,De Barros Lopes, Miguel A.,Ma, Shutao,Venter, Henrietta
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supporting information
p. 733 - 739
(2017/02/10)
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- Synthesis of 6-deoxymollugins and their inhibitory activities on tyrosinase
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A series of 6-deoxymollugins were prepared five steps from benzaldehyde and its derivatives via phenylboronic acid-catalyzed chromenylation as a key step. Their inhibitory activities against tyrosinase from mushroom were evaluated to show that the parent,
- Liang, Jing Lu,Javed, Umair,Lee, Seung Ho,Park, Jae Gyu,Jahng, Yurngdong
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p. 862 - 872
(2014/08/05)
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- Structural effect on the acid-catalyzed hydrolysis of methyl (E) 3-carboxy-4-aryl-3-butenoates and the isomeric hemiester (E) 3-methoxycarbonyl-4-aryl-3-butenoic acid
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The acid-catalyzed hydrolysis of hemiester methyl (E) 3-carboxy-4-(1- naphthyl)-3-butenoate (1) at different pH values (1.2-5.8), temperatures (35-50 °C) in 50% (v/v) aqueous dioxane shows that, the specific rate of reaction first decreases by increasing the pH value where it reaches a minimum at pH 2.1, followed by a rapid increase up to pH 4.8 then slightly increases until pH 5.8. The enhancement of the specific rate of hydrolysis of hemiester (1) by increasing the dielectric constant (D) of the medium (30-70% v/v dioxane) indicates the high polarity and greater solvation of the transition state more than the reactants. Structural effect of hemiesters are studied by comparison between reactivity of hemiester (1) which contains 1-naphthyl moiety with hemiesters methyl (E) 3-carboxy-4- phenyl-3-butenoate (2), methyl(E) 3-carboxy-4-(2-naphthyl)-3-butenoate (3), and its isomeric hemiester (E) 3-methoxycarbonyl-4-(2-naphthyl)-3-butenoic acid (4), shows the order of reactivity as (2)> (1)> (3)> (4). The activation parameters (E #), (δH#), (δS#), (δG #), and Arrhenius frequency factor (A), supports the structural reactivity assigned.
- Abdallah, Shadia Mahmoud
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experimental part
p. 455 - 459
(2012/07/17)
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- A new efficient synthesis of GR24 and dimethyl A-ring analogues, germinating agents for seeds of the parasitic weeds Striga and Orobanche spp.
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An efficient and high yielding preparation for the synthetic germination stimulant GR24 (5) and its A-ring dimethyl-substituted analogues 30-32 has been described. The first step involves a Stobbe condensation of benzaldehydes 9-11 with dimethyl succinate. Subsequent transposition of the ester and reduction of the double bond provides the building blocks 15-17 for an intramolecular Friedel-Crafts acylation. ABC-lactones 22-25 are prepared from γ-keto esters 18-21 by saponification, subsequent reduction with sodium borohydride followed by acid-catalyzed lactonization. Coupling of the lactones with the D-ring is accomplished by formylation and subsequent treatment with bromobutenolide 8 to give GR24 and its dimethyl analogues. Bioassays with Striga hermonthica seeds reveal that the dimethyl analogues are slightly less active than GR24 itself.
- Malik, Heetika,Rutjes, Floris P.J.T.,Zwanenburg, Binne
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experimental part
p. 7198 - 7203
(2010/10/02)
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- Catalytic asymmetric alkynylation and arylation of aldehydes by an H 8-binaphthyl-based amino alcohol ligand
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A novel chiral H8-1,1'-binaphthyl-based amino alcohol ligand (1Ra,2S,3R)-2 has been synthesized and applied in the direct nucleophilic addition of organozincs (alkynylzinc and arylzinc prepared in situ) to aldehydes, yielding the corresponding optically active propargylic alcohols and diarylmethanols in high yields and good to excellent enantioselectivities. For the asymmetric arylation reaction, one catalyst (1Ra,2S,3R)-2 can afford both enantiomers of many pharmaceutically interesting diarylmethanols by a proper combination of various arylzinc reagents and aldehydes.
- Ruan, Jiwu,Lu, Gui,Xu, Lijing,Li, Yue-Ming,Chan, Albert S. C.
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experimental part
p. 76 - 84
(2009/04/11)
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- Preparation of (R)-(-)- and (S)-(+)-3-hydroxymethyl-1-tetralone tosylates, key intermediates in the synthesis of new CNS drugs, via resolution of precursors
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The preparation of (R)-(-)- and (S)-(+)-3-hydroxymethyl-1-tetralone tosylates, key intermediates in the synthesis of new CNS drugs in the aminobutyrophenone family, has been developed via classical resolutions or lipase-catalyzed kinetic resolution of one of their precursors.
- Caro, Yolanda,Masaguer, Christian F.,Ravina, Enrique
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p. 381 - 387
(2007/10/03)
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- Method for preparing a substituted perhydroisoindole
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PCT No. PCT/FR98/01405 Sec. 371 Date Mar. 20, 2000 Sec. 102(e) Date Mar. 20, 2000 PCT Filed Jul. 1, 1998 PCT Pub. No. WO99/01430 PCT Pub. Date Jan. 14, 1999The present invention relates to a process for the industrial synthesis of a substituted perhydroisoindole of formula (I): and of pharmaceutically acceptable salts thereof. The compound of formula (I) and its addition salts have especially valuable pharmacological properties. It is a very powerful secretor of insulin, which makes it useful in the treatment of non-insulin-dependent diabetes.
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- HYDROXYAZIDO DERIVATIVES AND RELATED COMPOUNDS AS RENIN INHIBITORS
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Novel compounds useful as renin inhibitors are provided. The compounds are hydroxyazido derivatives having the structural formula STR1 wherein the substituents R 1 through R 7 are as defined herein. Analogs of these compounds which are ketozaido derivatives are also provided. Additionally disclosed re methods for using the novel compounds to treat hypertension, and pharmaceutical compositions containing the compounds. Of particular interest are formulations for oral administration.
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- Synthesis and Analgesic Effects of N--1-oxo-2(R)-benzylpropyl>-L-isoleucyl-L-leucine, a New Potent Inhibitor of Multiple Neurotensin/Neuromedin N Degrading Enzymes
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The synthesis of N--1-oxo-2(R)-benzylpropyl>-L-isoleucyl-L-leucine (JMV-390-1, 6a), a multipeptidase inhibitor based on the C-terminal sequence common to neurotensin (NT) and neuromedin N (NN), is described.This compound behaves as a full inhibitor of the major NT/NN degrading enzymes in vitro, e.g. endopeptidase 24.16, endopeptidase 24.15, endopeptidase 24.11, and leucine aminopeptidase (type IV-S), in the nanomolar range (IC50's from 30 to 60 nM).Compound 6a was found to increase endogenous recovery of NT and NN from slices of micehypothalamus depolarized with potassium.In various assays commonly used to select analgesics, e.g. hot-plate test, tail-flick test, acetic acid-induced writhing test, in mice, compound 6a proved to be potent when intracerebroventricularly (icv) injected.The analgesic effects observed were totally (hot-plate test) or largely (tail-flick test) reversed by the opioid antagonist naltrexone.Furthermore, icv injection of compound 6a (10 μg/mouse) was found to significantly potentiate the hypothermic effects of NT or NN.
- Doulut, Sylvie,Dubuc, Isabelle,Rodriguez, M.,Vecchini, F.,Fulcrand, H.,et al.
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p. 1369 - 1379
(2007/10/02)
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- Synthesis of Some Itaconates via Wittig Reaction
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The Wittig reaction of aromatic aldehydes with 1,2-bis-(ethoxycarbonyl) ethylidene triphenyl phosphorane (1) furnished oily mixtures of the two diastereomeric products (E) and (Z) (2).Alkaline hydrolysis of the diesters followed by fractional crystallizat
- Awad, William I.,Kandile, Nadia G.,Wassef, Wasfy N.,Mohamed, Mansoura I.
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p. 405 - 410
(2007/10/02)
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