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1.
Int J Mol Sci ; 25(16)2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39201437

RESUMEN

A new variant of Fisher indole synthesis involving Bronsted acid-catalyzed hydrohydrazination of unactivated terminal and internal acetylenes with arylhydrazines is reported. The use of polyphosphoric acid alone either as the reaction medium or in the presence of a co-solvent appears to provide the required balance for activating the C-C triple bond towards the nucleophilic attack of the hydrazine moiety without unrepairable reactivity loss of the latter due to competing amino group protonation. Additionally, the formal hydration of acetylenes to the corresponding ketones occurs under the same conditions, making it an alternative approach for generating carbonyl groups from alkynes.


Asunto(s)
Alquinos , Hidrazinas , Indoles , Alquinos/química , Indoles/química , Indoles/síntesis química , Hidrazinas/química , Ciclización , Catálisis , Aminación , Ácidos Fosfóricos/química , Estructura Molecular
2.
Int J Mol Sci ; 24(12)2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37373361

RESUMEN

The synthesis of novel, highly functionalized 5-hydroxy 3-pyrrolin-2-ones via a two-step procedure involving an addition reaction between KCN and corresponding chalcones, followed by ring condensation of the obtained ß-cyano ketones with het(aryl)aldehydes under basic conditions is described. This protocol enables the preparation of various 3,5-di-aryl/heteroaryl-4-benzyl substituted α,ß-unsaturated γ-hydroxy butyrolactams, which are subjects of significant interest to synthetic organic and medicinal chemistry.


Asunto(s)
Aldehídos , Cetonas , Humanos
3.
Molecules ; 28(9)2023 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-37175067

RESUMEN

A novel, low-cost method for the preparation of not easily accessible free 3-aminoindoles has been developed. This approach is based on a well-established reaction between indoles and nitrostyrene in the presence of phosphorous acid, which results in the formation of 4'-phenyl-4'H-spiro[indole-3,5'-isoxazoles]. The latter could be transformed to corresponding aminated indoles by reaction with hydrazine hydrate in good or excellent yields upon microwave-assisted heating.

4.
Molecules ; 28(7)2023 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-37049924

RESUMEN

The Friedel-Crafts reaction of novel 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones was used for low cost, one-pot preparation of polycyclic indole derivatives structurally similar to Ergot alkaloids.

5.
Molecules ; 28(5)2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36903571

RESUMEN

A straightforward three-step procedure affording a wide range of novel 7-aryl substituted paullone derivatives was developed. This scaffold is structurally similar to 2-(1H-indol-3-yl)acetamides-promising antitumor agents-hence, could be useful for the development of a new class of anticancer drugs.

6.
Org Biomol Chem ; 21(15): 3156-3166, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36945887

RESUMEN

A practical, one-pot approach to 3-anilino-4-(het)arylmaleimides by simple heating of aqueous DMSO solution of 2'-nitrochalcones with potassium cyanide in the presence of formic acid has been developed. This new reaction provides effective access to a variety of ß-substituted α-aminomaleimides which have recently become a subject of growing interest as small, easily modified and environmentally responsive fluorescent probes.

7.
Org Lett ; 9(9): 1753-5, 2007 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-17394350

RESUMEN

[reaction: see text] Encapsulation data for hydrophobic hydrocarbon gases within a water-soluble hemicarcerand in aqueous solution are reported. It is concluded that hydrophobic interactions serve as the primary driving force for the encapsulation, which can be used for the design of gas-separating polymers with intrinsic inner cavities.


Asunto(s)
Hidrocarburos/química , Interacciones Hidrofóbicas e Hidrofílicas , Gases , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estructura Molecular
8.
Chem Commun (Camb) ; (27): 2887-9, 2006 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-17007406

RESUMEN

SO2 gas is effectively used for the preparation of N,N'-diarylsulfamides and shape-persistent sulfamide polymers, which utilize a network of intermolecular N-H...O=S hydrogen bonds to self-assemble into soft porous materials.

9.
J Am Chem Soc ; 127(41): 14126-7, 2005 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-16218574

RESUMEN

A supramolecular approach for potential detection of SO2 is presented, which is based on the "old" donor-acceptor chemistry between SO2 and amines and includes an indicator-displacement assay. When amines were added to Zn-tetraphenylporphyrin 1 in CHCl3, the solution changed from red to dark green. A bathochromic shift of Deltalambda approximately 10 nm was observed for the Soret band, indicating the formation of 1*amine complexes. After this, SO2 gas was introduced, and the original red color of the solution was restored. The Soret band returned to its position for free porphyrin 1. The 1*amine complexes dissociated, and new SO2*amine adducts formed. Porphyrin 1 thus served as an indirect colorimetric indicator for SO2. The system discriminates between SO2 and such typical exhaust gases as COX, NOX, and H2O. From the indicator-displacement assay, the Kassoc values between 1000 and 30 000 M-1 for SO2*amine complexes were determined, which are comparable to those obtained by direct titration experiments between SO2 and the amines. Spectroscopic features of SO2*amine complexes are also presented.


Asunto(s)
Aminas/química , Dióxido de Azufre/química , Colorimetría/métodos , Indicadores y Reactivos , Estructura Molecular , Compuestos Organometálicos/química , Sensibilidad y Especificidad , Dióxido de Azufre/análisis , Zinc/química
11.
Chem Commun (Camb) ; (13): 1468-9, 2004 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-15216334

RESUMEN

A hemicarcerand encapsulates, stores and releases gases in the solid state.

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