- Selenoimidoylation of alcohols with selenium and isocyanides and its application to the synthesis of selenium-containing heterocycles
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The reaction of alcohols with selenium and isocyanides in the presence of DBU gave oxyimidoylselenoates 6. Trapping of 6 with BuI resulted in high-yield formation of selenocarbonimidates 4. When alk-2-yn-1-ols 9 were allowed to react with selenium and iso
- Asanuma, Yoshiaki,Fujiwara, Shin-Ichi,Shin-Ike, Tsutomu,Kambe, Nobuaki
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- Synthesis and leishmanicidal activity of novel urea, thiourea, and selenourea derivatives of diselenides
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A novel series of thirty-one N-substituted urea, thiourea, and selenourea derivatives containing diphenyldiselenide entities were synthesized, fully characterized by spectroscopic and analytical methods, and screened for their in vitro leishmanicidal activities. The cytotoxic activity of these derivatives was tested against Leishmania infantum axenic amastigotes, and selectivity was assessed in human THP-1 cells. Thirteen of the synthesized compounds showed a significant antileishmanial activity, with 50% effective concentration (EC50) values lower than that for the reference drug miltefosine (EC50, 2.84 M). In addition, the derivatives 9, 11, 42, and 47, with EC50 between 1.1 and 1.95 M, also displayed excellent selectivity (selectivity index ranged from 12.4 to 22.7) and were tested against infected macrophages. Compound 11, a derivative with a cyclohexyl chain, exhibited the highest activity against intracellular amastigotes, with EC50 values similar to those observed for the standard drug edelfosine. Structure-activity relationship analyses revealed that N-aliphatic substitution in urea and selenourea is recommended for the leishmanicidal activity of these analogs. Preliminary studies of the mechanism of action for the hit compounds was carried out by measuring their ability to inhibit trypanothione reductase. Even though the obtained results suggest that this enzyme is not the target for most of these derivatives, their activity comparable to that of the standards and lack of toxicity in THP-1 cells highlight the potential of these compounds to be optimized for leishmaniasis treatment.
- Díaz, Marta,de Lucio, Héctor,Moreno, Esther,Espuelas, Socorro,Aydillo, Carlos,Jiménez-Ruiz, Antonio,Toro, Miguel ángel,Gutiérrez, Killian Jesús,Martínez-Merino, Victor,Cornejo, Alfonso,Palop, Juan Antonio,Sanmartín, Carmen,Planoa, Daniel
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- Thermal stability and decomposition of urea, thiourea and selenourea analogous diselenide derivatives
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The fusion and thermal decomposition of thirty-three diselenide compounds with a urea, thiourea or selenourea group linked with different aliphatic or aromatic substituents have been studied by thermogravimetry, differential scanning calorimetry and mass spectrometry in order to perform comparative thermal stability studies among analogs. A relationship has been found between stability and a series of effects which occur in the compound structures. Analysis of the thermal data indicated that: (a) in general, compounds with a urea or selenourea group are more stable than those with a thiourea group; (b) no difference in stability exists when an aromatic or aliphatic group is linked to the thiourea group but when linked to the urea or selenourea groups, stability does differ; (c) selenourea compounds with aliphatic chain are the most unstable; and (d) the nature of the substituent located on the benzyl ring has no effects on thermal stability. Therefore, criteria for the selection of substituents can be established in order to improve the stability of these drugs. In addition, the mass spectral fragmentation in comparison with thermal analytical data helps in confirming the thermal behavior of the compounds.
- Díaz, Marta,Palop, Juan Antonio,Sanmartín, Carmen,Lizarraga, Elena
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p. 1663 - 1674
(2017/02/10)
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- One-pot synthesis of 1-substituted-5-alkylselanyl-1H-tetrazoles from isoselenocyanates: Unexpected formation of N-alkyl-N-arylcyanamides and (Z)-Se-alkyl-N-cyano-N,N′-diarylisoselenoureas
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1-Substituted-5-alkylsulfanyl-1H-tetrazoles are well known class of organic substances with various applications in medicinal chemistry or photographic industry. Their selenium analogues, 1-substituted-5-alkylselanyl-1H-tetrazoles are, however, much less explored because of the lack of suitable methods for their preparation. In this work we investigated the synthesis of 1-alkyl/aryl-5-alkylselanyl-1H-tetrazoles from synthetically available alkyl/arylisoselenocyanates. One-pot reactions of arylisoselenocyanates with sodium azide and alkylating agent led to the target 5-alkylselanyl-1-aryl-1H- tetrazoles but also to interesting side products, namely N-alkyl-N- arylcyanamides and (Z)-Se-alkyl-N-cyano-N,N′-diarylisoselenoureas. Nevertheless, when alkylisoselenocyanates were utilized as the substrates, the reactions led exclusively to the formation of 1-alkyl-5-alkylselanyl-1H- tetrazoles in good yields. This simple one-pot procedure brings new possibilities for the preparation of variously substituted selenium compounds. It also opens the way to further investigations of selenium isosteres of the widely utilized 5-thiotetrazole moiety in biomedical applications.
- Karabanovich, Galina,Roh, Jaroslav,Padělková, Zdeňka,Novák, Zdeněk,Vávrová, Kate?ina,Hrabálek, Alexandr
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p. 8798 - 8808
(2013/09/23)
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- "On water": Efficient iron-catalyzed cycloaddition of aziridines with heterocumulenes
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In suspension: The reaction of aziridines with heterocumulenes in the presence of Fe(NO3)3×9 H2O in aqueous suspension provides access to functionalized five-membered heterocycles in good to high yields. This protocol has a wide substrate scope, is simple, and uses a nontoxic and cheap catalyst. Copyright
- Sengoden, Mani,Punniyamurthy, Tharmalingam
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supporting information
p. 572 - 575
(2013/02/23)
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- One-pot synthesis of selenoureas and selenocarbamates via selenation of isocyanates with bis(dimethylaluminum) selenide
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Isocyanates were efficiently selenated by the reaction with bis(dimethylaluminum) selenide to give the corresponding isoselenocyanates. One-pot synthesis of unsymmetrical selenoureas and selenocarbamates was achieved in high yields by the subsequent addit
- Maeda, Hajime,Takashima, Masaru,Sakata, Koichi,Watanabe, Tatsuya,Honda, Mitsunori,Segi, Masahito
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experimental part
p. 415 - 417
(2011/02/28)
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- Synthesis of sugar-derived isoselenocyanates, selenoureas, and selenazoles
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Aryl, alkyl, and sugar-derived isoselenocyanates were prepared by a one-pot procedure starting from the corresponding formamides, using triphosgene as a dehydrating agent, triethylamine, and black selenium powder. The preparation of sugar selenoureas by coupling of O-protected sugar-derived isoselenocyanates with different amines, and by coupling of unprotected glycopyranosyl amines with phenyl isoselenocyanate was also accomplished. The synthesis of a glucopyranos-2-yl-selenazole starting from O-protected 2-amino-2-deoxy-d-glucose by coupling with benzoyl isoselenocyanate, Se-alkylation with phenacyl bromide, and acid-catalyzed dehydration is also reported. Unprotected N-(β-d-glucopyranosyl)-N′-phenylselenourea was transformed into a 1,2-trans-fused bicyclic isourea upon treatment with aqueous hydrogen peroxide; the same isourea was prepared by a one-pot three-step procedure from β-d-glycopyranosylamine by thiophosgenation, coupling with aniline, and HgO-mediated desulfurization.
- López, óscar,Maza, Susana,Ulgar, Víctor,Maya, Inés,Fernández-Bola?os, José G.
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experimental part
p. 2556 - 2566
(2009/08/08)
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- A Convenient and High Yielding Procedure for the Preparation of Isoselenocyanates. Synthesis and Reactivity of O-Alkylselenocarbamates.
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A high yielding one pot procedure for the preparation of isoselenocyanate from the corresponding formamide is reported.Various aromatic and aliphatic primary amines were employed in order to prepare the isoselenocyanates to establish the generality of the procedure.O-Alkylselenocarbamates of various primary, secondary and tertiary alcohols were synthesized and their stability and comparative reactivity were studied.Radical deoxygenation of the selenocarbamate of a secondary and a tertiary alcohol was accomplished under various conditions.
- Barton, Derek H. R.,Parekh, Shyamal I.,Tajbakhsh, Mahmoud,Theodorakis, Emmanouil A.,Tse, Chi-Lam
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p. 639 - 654
(2007/10/02)
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- Synthesis of the Heteroaromatic Selenatriazole Ring System. 5-Amino-1,2,3,4-selenatriazoles
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The synthesis of 5-amino-1,2,3,4-selenatriazoles, derivatives of the hitherto unknown selenatriazole ring system, is described.Reaction between bis(N,N-disubstituted selenocarbamoyl)selenides and azide ion gives the title compounds in good yield.The reactions of 4,4-dialkylselenosemicarbazides with nitrous acid or an aza-transfer reagent also lead to aminoselenatriazoles.Disubstituted aminoselenatriazoles are thermally unstable decomposing with formation of disubstituted cyanamides, nitrogen and selenium. 5-(Diethylamino)selenatriazole (half-life ca. 180 h in CHCL3 at 20 deg C) is thermally more stable than 5-(methylphenylamino)selenatriazole. 5-(Alkylamino)selenatriazoles decompose to hydrazoic acid and an isoselenocyanate, and evidence for their formation was only obtained indirectly.
- Jacobsen, Mogens,Henriksen, Lars,Holm, Arne
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p. 585 - 588
(2007/10/02)
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