Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Más filtros

Banco de datos
Tipo del documento
Publication year range
1.
Molecules ; 29(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38731410

RESUMEN

Cirsium japonicum Fisch. ex DC. (CF) and Cirsium setosum (Willd.) MB (CS) are commonly used clinically to stop bleeding and eliminate carbuncles. Still, CF is mainly used for treating inflammation, while CS favors hemostasis. Therefore, the present study used UHPLC-MS to analyze the main chemical constituents in CF-CS extract. We optimized the extraction process using single-factor experiments and response surface methodology. Afterward, the hemostatic and anti-inflammatory effects of CF-CS extract were investigated by determining the clotting time in vitro, the bleeding time of rabbit trauma, and the induction of rabbit inflammation using xylene and lipopolysaccharide. The study of hemostatic and anti-inflammatory effects showed that the CF-CS, CF, and CS extract groups could significantly shorten the coagulation time and bleeding time of rabbits compared with the blank group (p < 0.01); compared with the model group, it could dramatically inhibit xylene-induced ear swelling in rabbits and the content of TNF-α, IL-6, and IL-1ß in the serum of rabbits (p < 0.01). The results showed that combined CF and CS synergistically increased efficacy. CF-CS solved the problem of the single hemostatic and anti-inflammatory efficacy of a single drug, which provided a new idea for the research and development of natural hemostatic and anti-inflammatory medicines.


Asunto(s)
Antiinflamatorios , Cirsium , Hemostáticos , Extractos Vegetales , Animales , Conejos , Antiinflamatorios/farmacología , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Cirsium/química , Hemostáticos/farmacología , Hemostáticos/química , Hemostáticos/aislamiento & purificación , Extractos Vegetales/farmacología , Extractos Vegetales/química , Cromatografía Líquida de Alta Presión , Inflamación/tratamiento farmacológico , Inflamación/patología , Masculino
2.
J Org Chem ; 88(14): 9677-9685, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37389925

RESUMEN

This study describes the development of Rh-catalyzed [2,3]-sigmatropic rearrangement of alkynyl carbenes with allyl sulfides. The protocol exhibits equitable functional group tolerance and allows the formation of a variety of synthetically valuable sulfide-substituted 1,5-enyne products. To the best of our knowledge, this is the first example of [2,3]-sigmatropic rearrangement of alkynyl carbenes. DFT analysis supports the involvement of rhodium carbene generation, sulfonium ylides formation, and [2,3]-sigmatropic rearrangement pathway.

3.
J Org Chem ; 87(5): 2966-2974, 2022 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-35133818

RESUMEN

A transition-metal-free [2 + 1 + 3] cycloaddition of trifluoroacetaldehyde N-sulfonylhydrazone and hexahydro-1,3,5-triazine was described. This operationally simple protocol provides a general synthesis of diverse trifluoromethylated 2,3,4,5-tetrahydro-1,2,4-triazines in 81-97% yield with a broad substrate scope, including aryl, benzyl, and alkyl hexahydro-1,3,5-triazine.


Asunto(s)
Acetaldehído , Triazinas , Acetaldehído/análogos & derivados , Reacción de Cicloadición , Metales
4.
Org Biomol Chem ; 16(42): 7782-7786, 2018 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-30320861

RESUMEN

A Fe-catalyzed highly regioselective α,ß-difunctionalization of vinylarenes with diphenylphosphine oxides and anilines is disclosed, in which α,ß-aminophosphinoylation is efficiently and conveniently constructed under mild conditions with good functional compatibility and a broad substrate scope. The control experiments have revealed a radical reaction pathway.

5.
Org Biomol Chem ; 16(34): 6191-6194, 2018 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-30132495

RESUMEN

A novel highly selective Ag-catalyzed intermolecular amination of fluoroarenes has been developed. This transformation starts from readily available 4-carbonyl fluorobenzene and NaN3 or other nitrogen-source, via amination followed by C-F bond cleavage, thus affording the desired 4-carbonyl arylamine products under mild conditions. The reaction is accelerated using a small amount of water. This pathway is distinct from a previously reported radical amination reaction.

6.
Org Biomol Chem ; 15(47): 9974-9978, 2017 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-29167848

RESUMEN

A silver catalyzed decarboxylative C(sp2)-C(sp3) coupling of vinylic carboxylic acids with alcohols, alkylbenzenes, cycloalkanes and cyclic ethers was developed by using DTBP as an oxidant. This reaction tolerates a wide range of substrates, and products are obtained in good to excellent yields. The reaction also shows good stereoselectivity, and only trans-isomers are obtained. In addition, a radical pathway would be involved to facilitate this decarboxylative C(sp2)-C(sp3) coupling reaction.

7.
Angew Chem Int Ed Engl ; 53(28): 7209-13, 2014 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-24888888

RESUMEN

Cyclopentadienes are valuable intermediates in organic synthesis and also ubiquitous as the Cp ligands in organometallic chemistry. As part of ongoing efforts to develop novel organic reactions that employ functionalized alkynes, a [3+2] cycloaddition of propargylic alcohols and ketene dithioacetals has been developed, which leads to fully substituted 2,5-dialkylthio cyclopentadienes in good to excellent yields. In an unusual dethiolating Diels-Alder reaction, the cyclopentadienes were further reacted with maleimides to afford a family of novel fluorescent polycyclic compounds.

8.
Org Lett ; 24(35): 6374-6379, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36018352

RESUMEN

We herein report the first example of an iminyl-radical-mediated formal 1,3-HAT/radical coupling cascade of vinyl azides leading to the synthesis of tetrasubstituted gem-disulfonyl enamines. It is possible to employ a variety of vinyl azides and sulfinate salt coupling elements without sacrificing effectiveness and scalability. The combination of experimental studies and DFT calculations showed that this reaction proceeds via a radical addition/formal 1,3-HAT/radical coupling mechanism.

9.
Org Lett ; 24(48): 8920-8924, 2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36445043

RESUMEN

Herein we describe the pioneering Rh-catalyzed coupling reactions of a fluoroalkyl carbene with azides to access α-trifluoroethylated imines, where fluoroalkyl N-sulfonylhydrazones are used as fluoroalkyl diazo surrogates. Remarkably, using TMSN3 as the N source, two C-N bond formation products were obtained. Furthermore, the α-trifluoroethylated imine products could be easily reduced to the corresponding N-trifluoroethylated anilines. Experimental results and theoretical calculations justify a stepwise reaction pathway involving the formation of rhodium carbene, the addition of HN3, and C═N bond formation.

11.
Nanomaterials (Basel) ; 7(12)2017 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-29257075

RESUMEN

Development of highly active heterogeneous catalysts is an effective strategy for modern organic synthesis chemistry. In this work, acidic mesoporous zeolite ZSM-5 (HZSM-5-M), acidic-free mesoporous zeolite TS-1 (TS-1-M), and basic ETS-10 zeolite supported metal Cu catalysts were prepared to investigate their catalytic performances in the hydroxysulfurization of styrenes with diaryl disulfides. The effect of pore size and acidities of the supports, as well as the Cu species electronic properties of the catalysts on reaction activity were investigated. The results show that Cu⁺ and Cu2+ binded on HZSM-5-M show the highest activity and product selectivity for the desired ß-hydroxysulfides compounds.

12.
Chem Commun (Camb) ; 52(74): 11120-3, 2016 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-27550149

RESUMEN

An efficient copper-catalyzed radical decarboxylative imidation reaction is presented. This strategy is carried out through the copper(i)-catalyzed decarboxylative C(sp(3))-N and C(sp(2))-N coupling of carboxylic acids with N-fluoroarylsulfonimides. The reaction shows good functional group tolerance and it provides a new approach for decarboxylative imidation. Preliminary mechanistic studies of this transformation suggest an involvement of N-centered radical species.

13.
Chem Commun (Camb) ; 52(15): 3115-8, 2016 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-26794615

RESUMEN

Zeolite Y nanosheets with a micro-meso-macroporous structure were synthesized, and applied in the assembly of a Pd catalyst (Pd/NS-Y) for direct vinylation of thiophenes with high activity and selectivity, as compared to Pd(OAc)2, Pd(NO3)2, and Pd(PPh3)4 catalysts. This feature should be assigned to the highly dispersed Pd(δ+) (δ < 2) species in Pd/NS-Y, which are more active than Pd(2+).

14.
Org Lett ; 17(4): 782-5, 2015 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-25654311

RESUMEN

An atom-economic route to benzo[f]-1-indanone frameworks has been developed starting from the readily available gem-dialkylthio trienynes by intramolecular annulations. The chemoselectivity of the intramolecular cyclizations can be regulated by both the base and the type of gas atmosphere used in the reaction, thus allowing the divergent synthesis of the corresponding functionalized benzo[f]-1-indanones in good to excellent yields.


Asunto(s)
Alquinos/química , Indanos/síntesis química , Compuestos de Sulfhidrilo/química , Catálisis , Ciclización , Indanos/química , Estructura Molecular , Estereoisomerismo
15.
Chem Commun (Camb) ; 51(27): 5890-3, 2015 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-25729783

RESUMEN

A Cu-doped zeolite ZSM-5 (Cu-ZSM-5-M) with a micro-meso-macroporous structure was directly synthesized, and it exhibits excellent catalytic activity and good recyclability in the cross-coupling of aryl halides with diphenyl disulfides. This feature should be attributed to the structural characteristics of meso-macropores and homogeneous dispersion of active Cu(δ+) (δ < 2) species in Cu-ZSM-5-M.

16.
Org Lett ; 16(5): 1522-5, 2014 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-24555707

RESUMEN

A copper(I)-catalyzed, regioselective C-H α-trifluoromethylation of α,ß-unsaturated carbonyl compounds using Togni's reagent was developed. Diverse substrates, including enones as well as α,ß-unsaturated esters, thioesters, and amides, stereospecifically afforded the corresponding (E)-α-trifluoromethylated products in moderate to high yields. Further, this method was applied to the C-H trifluoromethylation of drugs.


Asunto(s)
Cobre/química , Hidrocarburos Fluorados/síntesis química , Yoduros/química , Cetonas/química , Cetonas/síntesis química , Amidas/química , Catálisis , Hidrocarburos Fluorados/química , Indicadores y Reactivos , Estructura Molecular , Estereoisomerismo
17.
Chem Commun (Camb) ; 48(70): 8802-4, 2012 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-22836930

RESUMEN

gem-Dialkylthio vinylallenes were obtained for the first time and applied to the divergent synthesis of fully-substituted pyrroles and thiophenes by domino cyclizations. These two cyclization pathways were regulated by alkylthio groups. Plausible reaction mechanisms were presented and supported by DFT calculations. An unprecedented metal-free carbothiolation was discovered in the formation of thiophenes.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda