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1.
Nat Commun ; 12(1): 4065, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210971

RESUMO

Strategies that enable intermolecular site-selective C-H bond functionalisation of organic molecules provide one of the cornerstones of modern chemical synthesis. In chloroalkane synthesis, such methods for intermolecular site-selective aliphatic C-H bond chlorination have, however, remained conspicuously rare. Here, we present a copper(I)-catalysed synthetic method for the efficient site-selective C(sp3)-H bond chlorination of ketones, (E)-enones and alkylbenzenes by dichloramine-T at room temperature. A key feature of the broad substrate scope is tolerance to unsaturation, which would normally pose an immense challenge in chemoselective aliphatic C-H bond functionalisation. By unlocking dichloramine-T's potential as a chlorine radical atom source, the product site-selectivities achieved are among the most selective in alkane functionalisation and should find widespread utility in chemical synthesis. This is exemplified by the late-stage site-selective modification of a number of natural products and bioactive compounds, and gram-scale preparation and formal synthesis of two drug molecules.


Assuntos
Domínio Catalítico , Cobre/química , Cetonas/química , Sulfonamidas/química , Produtos Biológicos/química , Carbono/química , Catálise , Halogenação , Hidrogênio/química , Temperatura
2.
Acta Pharm Sin B ; 9(3): 537-544, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31193773

RESUMO

We report in this study the identification of a natural product-like antagonist (1a) of Vps34 as a potent autophagy modulator via structure-based virtual screening. Aurone derivative 1a strongly inhibited Vps34 activity in cell-free and cell-based assays. Significantly, 1a prevents autophagy in human cells induced either by starvation or by an mTOR inhibitor. In silico modeling and kinetic data revealed that 1a could function as an ATP-competitive inhibitor of Vps34. Moreover, it suppressed autophagy in vivo and without inducing heart or liver damage in mice. 1a could be utilized as a new motif for more selective and efficacious antagonists of Vps34 for the potential treatment of autophagy-related human diseases.

3.
Angew Chem Int Ed Engl ; 57(43): 14235-14239, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30179295

RESUMO

A synthetic method to prepare bicyclo[6.3.0]undeca-2,4,9,trienyl esters efficiently from gold(I)-catalyzed Rautenstrauch rearrangement/1,5-hydride shift/8-endo-dig cyclization of 1-ene-4,10-diynyl esters is described. The suggested double cycloisomerization mechanism delineates the first example of an unactivated all-carbon tethered 1,7-enyne, either preformed or formed in situ, which undergoes an 8-endo-dig cyclization pathway to give a cyclooctane motif. It also offers an extremely rare synthetic method in organic chemistry that can sequentially assemble both ring components of the bicyclic motif from an acyclic precursor in one step.

4.
Chem Asian J ; 12(13): 1475-1479, 2017 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-28608646

RESUMO

A synthetic method for the efficient assembly of benzo[c]carbazole derivatives that relies on silica gel-activated benzoic acid-mediated cycloaromatization of 1H-indol-2-yl propargyl benzoates under atmospheric conditions is described. Robust with a variety of substitution patterns tolerated, the reaction provides a one-step strategy to construct a member of the N-heterocycles family in good to excellent yields. A tentative mechanism is proposed in which the cycloaromatization process is thought to involve a Brønsted acid-mediated formal 1,3-acyloxy migration/6π-electrocyclization pathway.

5.
J Org Chem ; 82(6): 2826-2834, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28225621

RESUMO

A synthetic method to prepare partially hydrogenated isoquinolines efficiently from silver-mediated [3,3]-sigmatropic rearrangement/Diels-Alder reaction of 1,9-dien-4-yne esters is described. The reactions were shown to be robust with a wide variety of substitution patterns tolerated to provide the corresponding nitrogen-containing heterocyclic products in good to excellent yields. This includes examples containing a bridgehead sp3 quaternary carbon center as well as the cycloisomerization of one substrate to give the corresponding bicyclic adduct in excellent yield at the gram scale.

6.
Chempluschem ; 82(1): 8-17, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31961508

RESUMO

Aptamers are nucleic acid sequences that can recognize and bind to analytes with high affinity and selectivity. Intriguingly, a number of aptamers undergo a conformational change within the G-quadruplex motif upon ligand binding. This Minireview aims to highlight interesting examples of luminescent G-quadruplex aptamer-based probes that have been developed in recent years. Various mechanisms and sensing modes are described, and the outlook and future directions of this field are also discussed.

7.
Org Lett ; 18(22): 5936-5939, 2016 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-27791382

RESUMO

A synthetic method for the efficient assembly of bicyclo[2.2.1]hept-2-en-7-ones that relies on gold(I)-catalyzed Rautenstrauch rearrangement followed by Brønsted acid-mediated formal [3 + 2]-cycloaddition/deacetylation of 1,8-diynyl vinyl acetates at room temperature under atmospheric conditions is described.

8.
Org Lett ; 18(18): 4730-3, 2016 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27589481

RESUMO

A synthetic method that relies on Au(I)-catalyzed tandem 1,3-acyloxy migration/double cyclopropanation of 1-ene-4,9-diyne and 1-ene-4,10-diyne esters to construct the respective architecturally challenging tetracyclodecene and tetracycloundecene derivatives is described. Achieved under mild reaction conditions, the transformation was shown to be robust with a wide variety of substitution patterns tolerated to give the two members of the carbocyclic family in good to excellent yields and as a single regio- and diastereomer.

9.
Chemistry ; 22(19): 6532-6, 2016 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-26945940

RESUMO

A synthetic method that relies on a gold(I)-catalyzed cycloisomerization of 1-en-3,9-diyne esters to spiro[4.4]non-2-ene-substituted 1,2-dihydronaphthalenes is described. Robust with a wide variety of substitution patterns tolerated, the reaction provides the first example of a one-step strategy to construct such novel and architecturally challenging members of the carbocycle family in good to excellent yields. A mechanism is proposed in which the sequential cycloisomerization pathway was thought to involve a gold-catalyzed 1,3-acyloxy migration/Nazarov cyclization followed by a formal [4+2] cycloaddition to give the tetracarbocyclic product.

10.
Org Biomol Chem ; 14(3): 844-8, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26626538

RESUMO

The synthesis of 1,4-amino alcohols from THF treated with N-tosyliminobenzyliodinane (PhINTs) followed by a Grignard reagent under mild reaction conditions at room temperature is described herein. Various Grignard reagents were shown to be compatible, furnishing the corresponding 4-substituted-N-1,4-tosylamino alcohols in good to excellent yields. A partial or full detosylation of the N-tosyl-1,4-amino alcohol was observed in instances involving a sterically bulky Grignard reagent, leading to the deprotected 1,4-amino alcohol product in moderate to good yields. The synthetic utility of this protocol was demonstrated by the synthesis of a 5-substituted-N-tosyl-1,5-amino alcohol from THP and the conversion of two examples to their corresponding γ-lactam and pyrrolidine adducts.

11.
Chem Asian J ; 11(3): 385-9, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26586026

RESUMO

A synthetic method to prepare (E)-(pyridin-2-yl)enones and (E)-(quinolin-8-yl)enones that relies on the respective copper(I)-catalyzed formal cross-dehydrogenative coupling (CDC) reaction of 2-methylpyridine and 8-methylquinoline with methyl ketones has been discovered. The mechanism was delineated to follow a pathway involving oxidation of the N-heterocycle to its corresponding aldehyde adduct prior to reaction with the methyl ketone. The versatility and substrate dependent divergence in the reactivity of the copper-mediated CDC strategy was exemplified by its application to the synthesis of N-(quinolin-8-ylmethyl)amide and N-(quinolin-8-ylmethyl)aniline adducts on switching the cross-coupling partner to benzamides or an aniline derivative.

12.
Org Lett ; 17(17): 4176-9, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26291118

RESUMO

A method for the efficient preparation of hydronaphthalene and -cinnoline derivatives by Au(I)-catalyzed cycloisomerzation of 1,6-diyne esters followed by a Diels-Alder reaction with alkenes or diazenes under mild conditions at room temperature with catalyst loadings as low as 1 mol % is described.


Assuntos
Ouro/química , Compostos Heterocíclicos com 2 Anéis/química , Imidas/química , Naftalenos/química , Catálise , Técnicas de Química Combinatória , Ésteres , Estrutura Molecular
13.
Molecules ; 20(7): 13336-53, 2015 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-26205058

RESUMO

A one-pot, two-step approach to prepare 2-tetrahydrofuran and -pyran substituted 1,3-dicarbonyl compounds by PhI=NTs-mediated amination/Brønsted base-catalyzed cross dehydrogenative coupling (CDC) reaction of the cyclic ether and 1,3-dicarbonyl derivative under mild conditions is reported. The reaction is compatible with a variety of cyclic ethers and 1,3-dicarbonyl compounds, affording the corresponding coupled products in moderate to good yields of up to 80% over two steps.


Assuntos
Éteres Cíclicos/química , Éteres Cíclicos/síntese química
14.
Chemistry ; 21(25): 9111-8, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25982956

RESUMO

A synthetic method to prepare 3a,6-methanoisoindole esters efficiently by gold(I)-catalyzed tandem 1,2-acyloxy migration/Nazarov cyclization followed by Diels-Alder reaction of 1,4,9-dienyne esters is described. We also report the ability of one example to inhibit binding of tumor necrosis factor-α (TNF-α) to the tumor necrosis factor receptor 1 (TNFR1) site and TNF-α-induced nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activation in cell at a half-maximal inhibitory concentration (IC50 ) value of 6.6 µM. Along with this is a study showing the isoindolyl derivative to exhibit low toxicity toward human hepatocellular liver carcinoma (HepG2) cells and its possible mode of activity based on molecular modeling analysis.


Assuntos
Alcinos/química , Citocinas/química , Ouro/química , Isoindóis/síntese química , Isoindóis/farmacologia , Neoplasias Hepáticas/química , Fator de Necrose Tumoral alfa/química , Catálise , Reação de Cicloadição , Ésteres , Células Hep G2 , Humanos , Concentração Inibidora 50 , Isoindóis/química , Estrutura Molecular , Fator de Necrose Tumoral alfa/agonistas , Fator de Necrose Tumoral alfa/metabolismo
15.
J Am Chem Soc ; 137(19): 6350-5, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25905645

RESUMO

A synthetic method to prepare tricyclic bridged heptenones and hexenones from gold(I)-catalyzed double cycloisomerization of 1,11-dien-3,9-diyne benzoates is described. A divergence in product selectivity was achieved by fine-tuning the steric nature of the ligand of the Au(I) catalyst. In the presence of [MeCNAu(JohnPhos)](+)SbF6(-) (JohnPhos = (1,1'-biphenyl-2-yl)-di-tert-butylphosphine) as the catalyst, tandem 1,3-acyloxy migration/metallo-Nazarov cyclization/1,6-enyne addition/Cope rearrangement of the substrate was found to selectively occur to afford the bridged heptenone adduct. In contrast, changing the Au(I) catalyst to [MeCNAu(Me4tBuXPhos)](+)SbF6(-) (Me4tBuXPhos = di-tert-butyl(2',4',6'-triisopropyl-3,4,5,6-tetramethyl-[1,1'-biphenyl]-2-yl)phosphine) was observed to result in the 1,11-dien-3,9-diyne benzoate undergoing a more rapid tandem 1,3-acyloxy migration/metallo-Nazarov cyclization/[4 + 2]-cyclization pathway to give the bridged hexenone derivative.

16.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 1): o64, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25705512

RESUMO

The mol-ecule of the title compound, C25H24O, obtained by acid-catalysed 1,3-migration of an alcohol group, is T-shaped. The planes of the two phenyl rings are inclined to one another by 81.9 (2)°. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains along [001].

17.
Sci Technol Adv Mater ; 16(6): 065004, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27877846

RESUMO

We report herein the use of an exonuclease III and G-quadruplex probe to construct a G-quadruplex-based luminescence detection platform for Hg2+. Unlike common DNA-based Hg2+ detection methods, when using the dsDNA probe to monitor the hairpin formation, the intercalation of the dsDNA probe may be influenced by the distortion of dsDNA. This 'mix-and-detect' methodology utilized the G-quadruplex probe as the signal transducer and is simple, rapid, convenient to use and can detect down to 20 nM of Hg2+.

18.
Methods ; 71: 38-43, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25160651

RESUMO

STAT3 modulates the transcription of a wide variety of regulatory genes involved in cell proliferation, differentiation, migration, apoptosis, and other critical cellular functions. Constitutive activation of STAT3 has been detected in a wide spectrum of human malignancies. A pharmacophore model constructed from a training set of STAT3 inhibitors binding to the SH2 domain was used to screen an in-house database of compounds, from which azepine 1 emerged as a top candidate. Compound 1 inhibited STAT3 DNA-binding activity in vitro and attenuated STAT3-directed transcription in cellulo with comparable potency to the well-known STAT3 inhibitor S3I-201. A fluorescence polarization assay revealed that compound 1 targeted the SH2 domain of STAT3. Furthermore, compound 1 inhibited STAT3 phosphorylation in cells without affecting the total expression of STAT3. This study also validates the use of pharmacophore modeling to identify inhibitors of protein-protein interactions.


Assuntos
Descoberta de Drogas/métodos , Fator de Transcrição STAT3/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos/métodos , Células HeLa , Humanos , Modelos Químicos , Modelos Moleculares , Fator de Transcrição STAT3/química
19.
Methods ; 71: 92-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25260600

RESUMO

Tumor necrosis factor α-converting enzyme (TACE) plays a critical role in diverse physiological processes such as inflammation, hematopoiesis, and development. In this study, a pharmacophore model constructed from a training set of TACE inhibitors was used to screen an in-house database of organic compounds, from which compound 1 emerged as a top candidate. In a cell-free assay, compound 1 inhibited TACE enzymatic activity in a dose-dependent manner. Moreover, compound 1 inhibited the production of soluble TNF-α in human acute monocytic leukemia THP-1 cells without impacting nitric oxide production, and exhibited anti-proliferative activity against THP-1 cells. We envisage that compound 1 may be employed as a useful scaffold for the development of more potent TACE inhibitors. This study also validates the use of pharmacophore modeling to identify enzyme inhibitors.


Assuntos
Proteínas ADAM/antagonistas & inibidores , Descoberta de Drogas/métodos , Modelos Moleculares , Proteínas ADAM/química , Proteína ADAM17 , Linhagem Celular Tumoral , Simulação por Computador , Bases de Dados de Compostos Químicos , Humanos
20.
J Org Chem ; 79(23): 11301-15, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25263810

RESUMO

A synthetic method to chemoselectively prepare 1H-cyclopenta[b]naphthalenes, cis-cyclopenten-2-yl δ-diketones, and bicyclo[3.2.0]hepta-1,5-dienes efficiently by gold-catalyzed cycloisomerization of 1,6-diyne esters is described. These three product classes were accessed divergently by taking advantage of the electronic and steric differences between a phosphine and NHC (NHC = N-heterocyclic carbene) ligand in the respective gold(I) complexes and that of gold(III) complex combined with substrate substitution patterns and optimized reaction conditions. In the presence of [PhCNAuIPr](+)SbF6(-) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidine) as the catalyst, substrates with a pendant aryl group at the acetate alkynyl position were found to undergo preferential 1,3-acyloxy migration/5-exo-dig cyclization/Friedel-Crafts reaction to give 1H-cyclopenta[b]naphthalenes. In contrast, the analogous reactions with PicAuCl2 (Pic =2-picolinate) were found to proceed by selective 1,3-acyloxy migration/5-exo-dig cyclization/1,5-acyl migration to afford cis-cyclopenten-2-yl δ-diketones. Changing the catalyst to [MeCNAu(JohnPhos)](+)SbF6(-) (JohnPhos = (1,1'-biphenyl-2-yl)-di-tert-butylphosphine) and the acetate alkynyl position from an aryl to vinyl substituent in the starting ester led to 1,3-acyloxy migration/5-exo-dig cyclization/Prins-type [2 + 2]-cycloaddition to provide bicyclo[3.2.0]hepta-1,5-dienes.

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