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1.
Chemistry ; 26(52): 12036-12042, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32297686

RESUMO

Cyclic RGD peptides are well-known ligands of integrins. The integrins αV ß3 and α5 ß1 are involved in angiogenesis, and integrin αV ß3 is abundantly present on cancer cells, thus representing a therapeutic target. Hence, synthetic and biophysical studies continuously are being directed towards the understanding of ligand-integrin interaction. In this context, the development of versatile synthetic strategies to obtain fluorescent building blocks that can add molecular diversity and modular spectral characteristics while not compromising binding affinity or selectivity is a relevant task. An on-resin intramolecular Suzuki-Miyaura cross-coupling (SMC) between l- or d-7-bromotryptophan (7BrTrp) and a phenothiazine (Ptz) boronic acid affords fluorescent cyclic RGD pseudopeptides, c(RGD(W/w)Ptz). Ring closure by SMC establishes a phenothiazine-indole moiety with axial chirality. An array of eight novel compounds has been synthesized, among them one fluorescent compound with good affinity to integrin αV ß3 . The fluorescence properties of the analogues can be efficiently tuned depending on the substituents in Ptz moiety even for fluorescence emission in the visible (red) spectral range.


Assuntos
Oligopeptídeos/química , Fluorescência , Integrina alfaVbeta3 , Ligantes , Fenotiazinas
2.
J Org Chem ; 82(23): 12141-12152, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29048893

RESUMO

A diversity-oriented access to diastereoselective arylidene 2,5-diketopiperazines is elaborated via a sequential Ugi post-transformation involving catalytic cyclization and oxidative Heck reaction sequence. This sequence offers an interesting multicomponent entry to a library of 2,5-diketopiperazines and arylidene 2,5-diketopiperazines under mild reaction conditions in good to excellent yields.

3.
J Org Chem ; 79(17): 7926-34, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25105212

RESUMO

An efficient approach for the synthesis of functionalized ß-lactams and pyrrolidine-2,5-diones was achieved through a sequential Ugi-4CR/cyclization reaction. Diversity-oriented synthesis, good to high yields, easy workup, and short reaction times are advantages of this procedure.


Assuntos
Metais/química , Pirrolidinonas/síntese química , beta-Lactamas/síntese química , Técnicas de Química Combinatória/métodos , Ciclização , Estereoisomerismo
4.
Org Biomol Chem ; 12(30): 5757-65, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-24968923

RESUMO

An efficient sequential four-component reaction of chromone carbaldehydes, Meldrum's acid, 4-hydroxyl coumarin or 6-methyl-4-hydroxyl-pyrone and primary alcohols is reported which leads to 5a-i in aqueous media. Replacing the primary alcohol with isopropyl alcohol and tert-butyl alcohol results in different products 10 and 11. The environmentally friendly features, good to high yields and easy work-up are advantages of this approach.


Assuntos
Cromonas/química , Cromonas/síntese química , Água/química , Butanóis/química , Conformação Molecular
5.
Mol Divers ; 18(3): 535-43, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24792225

RESUMO

Novel analogs of 2-pyridone-3-carboxylic acids 4a-l have been prepared by the three-component reaction of 3-formyl chromone, Meldrum's acid, and primary amines in the presence of a catalytic amount of diammonium hydrogen phosphate in water. Good-to-high yields, easy work-up, and an environmentally friendly profile are the advantages of this method for the synthesis of 2-pyridone-3-carboxylic acid derivatives.


Assuntos
Ácidos Carboxílicos/química , Ácidos Carboxílicos/síntese química , Água/química , Aminas/química , Técnicas de Química Sintética , Fosfatos/química
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