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1.
Top Curr Chem (Cham) ; 378(1): 11, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31903506

RESUMO

The dramatic increase in atmospheric carbon dioxide (CO2) concentrations has attracted human attention and many strategies about converting CO2 into high-value chemicals have been put forward. Metal-organic frameworks (MOFs), as a class of versatile materials, have been widely used in CO2 capture and chemical conversion, due to their unique porosity, multiple active centers and good stability and recyclability. Herein, we focused on the processes of chemical conversion of CO2 by MOFs-based catalysts, including the coupling reactions of epoxides, aziridines or alkyne molecules, CO2 hydrogenation, and other CO2 conversion reactions. The synthesized methods and high catalytic activity of MOFs-based materials were also analyzed systematically. Finally, a brief perspective on feasible strategies is presented to improve the catalytic activity of novel MOFs-based materials and explore the new CO2 conversion reactions.


Assuntos
Dióxido de Carbono/química , Estruturas Metalorgânicas/química , Alcenos/química , Aminas/química , Aziridinas/química , Catálise , Compostos de Epóxi/química , Hidrogenação , Líquidos Iônicos/química
2.
Chem Commun (Camb) ; 56(14): 2194-2197, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31971170

RESUMO

An Ugi, novel pseudo-Knoevenagel, ring expansion cascade reaction was discovered and utilized for the synthesis of aziridinyl succinimides in one-pot. Subsequently, densely functionalized aziridines and maleimides have been designed and synthesized through similar cascade reactions. The target compounds were prepared by means of a mild reaction and a simple operation procedure, which could be applicable to a broad scope of starting materials. This series of novel cascade reactions generates opportunities for the tailored synthesis of a wide range of biologically active scaffolds through tuneable Ugi inputs. Discovery of compound 8i with comparable potency to sorafenib in liver cancer cell lines could provide a new avenue for liver cancer drug discovery.


Assuntos
Antineoplásicos/farmacologia , Aziridinas/farmacologia , Maleimidas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Aziridinas/síntese química , Aziridinas/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Maleimidas/síntese química , Maleimidas/química , Estrutura Molecular
3.
Molecules ; 24(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615035

RESUMO

Poly(ethyleneimine) (PEI) is a weakly basic, synthetic, polycationic polymer, due to the presence of primary, secondary, and tertiary amino groups. The amino groups are responsible for the variety of applications of PEI (e.g., transfection, bioimaging, solar cell, etc.). Our study presents some new and reproducible methods for the quantification of molecular or mass concentration of highly branched PEI of different molecular weights (800-2000-25,000-750,000 MW PEI). In the course of the direct method, spectrophotometry and fluorometry were applied to determine the absorption and fluorescence of PEI dilution series. An increase in the MW at the same concentration produces a higher count number because of the higher number of amino groups in PEI molecules. The character of increment in fluorescence intensity is essentially different in the case of mass concentrations and molar concentrations. The increment of the fluorescence intensity related to the molar concentration is non-linear. In the case of mass concentration, the slope is linear. Moreover, their fluorescence is enhanced with the decrease in pH values. The spectrophotometry is a reliable method for measuring the quantity of PEI molecules in solution. Our data help in recognizing the detailed properties of PEI in dendrimer research.


Assuntos
Dendrímeros/química , Fluorescência , Polietilenoimina/química , Aziridinas/química , Cátions/química , Concentração de Íons de Hidrogênio , Peso Molecular , Polímeros/química
4.
Chem Biodivers ; 16(11): e1900375, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31512351

RESUMO

New aziridine 2-phosphonic acids were prepared by monohydrolysis of the aziridine 2-phosphonates that were obtained by the modified Gabriel-Cromwell reaction of vinyl phosphonate or α-tosylvinyl phosphonate with a primary amine or a chiral amine. The cellular cytotoxicity of these compounds was tested against the HCT-116 colorectal cancer cell lines and the CCD-18Co normal colon fibroblast lines using the MTT assay. Three of the synthesized phosphonic acid derivatives 2e (ethyl hydrogen {(2S)-1-[(1S)-1-(naphthalen-2-yl)ethyl]aziridin-2-yl}phosphonate), 2h (ethyl hydrogen (1-benzylaziridin-2-yl)phosphonate), and 2i (ethyl hydrogen (1-cyclohexylaziridin-2-yl)phosphonate) showed higher cytotoxicity than the reference cancer treatment agent etoposide. Cell death was through a robust induction of apoptosis even more effectively than etoposide, a well-known apoptosis inducing agent.


Assuntos
Antineoplásicos/farmacologia , Aziridinas/farmacologia , Ácidos Fosforosos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Aziridinas/síntese química , Aziridinas/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Ácidos Fosforosos/síntese química , Ácidos Fosforosos/química
5.
Chem Commun (Camb) ; 55(71): 10567-10570, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31417998

RESUMO

Macrocyclization of linear peptide precursors using the Petasis borono-Mannich reaction affords a diverse range of macrocycles with an endocyclic amine. Analysis of the corresponding macrocyclic structures underscores that the hydrogen bond between an endocyclic amine and the adjacent amide NH is a powerful control element for conformationally homogenous peptide macrocycles.


Assuntos
Ácidos Borônicos/química , Compostos Macrocíclicos/síntese química , Peptídeos Cíclicos/síntese química , Aldeídos/química , Amidas/química , Aminas/química , Aziridinas/química , Ciclização
6.
Molecules ; 24(14)2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31295845

RESUMO

A recent computational analysis of the stabilizing intramolecular OH⋯O contact in 1,2-dialkyl-2,3-epoxycyclopentanol diastereomers has been extended to thiiriane, aziridine and phosphirane analogues. Density functional theory (DFT), second-order Møller-Plesset perturbation theory (MP2) and CCSD(T) coupled-cluster computations with simple methyl and ethyl substituents indicate that electronic energies of the c i s isomers are lowered by roughly 3 to 4 kcal mol-1 when the OH group of these cyclopentanol systems forms an intramolecular contact with the O, S, N or P atom on the adjacent carbon. The results also suggest that S and P can participate in these stabilizing intramolecular interactions as effectively as O and N in constrained molecular environments. The stabilizing intramolecular OH⋯O, OH⋯S, OH⋯N and OH⋯P contacts also increase the covalent OH bond length and significantly decrease the OH stretching vibrational frequency in every system with shifts typically on the order of -41 cm-1.


Assuntos
Aziridinas/química , Ciclopentanos/química , Compostos de Epóxi/química , Modelos Teóricos , Sulfetos/química , Teoria da Densidade Funcional , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Estrutura Molecular
7.
Org Biomol Chem ; 17(29): 6998-7001, 2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31304944

RESUMO

A novel and efficient Cu(i)-catalyzed homo-coupling of indanone derivatives using diaziridinone as an oxidant is described. A variety of 1,4-dicarbonyl compounds bearing two adjacent quaternary stereocenters were obtained in high yields with high diastereoselectivities via a base-free and operationally simple process under mild reaction conditions.


Assuntos
Aziridinas/química , Complexos de Coordenação/química , Cobre/química , Indanos/síntese química , Catálise , Indanos/química , Estrutura Molecular , Estereoisomerismo
8.
Chemistry ; 25(43): 10226-10231, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31161639

RESUMO

A Pd-catalyzed enantiospecific and regioselective ring-opening Suzuki-Miyaura arylation of aziridine-2-carboxylates was developed. The cross-coupling allows for the asymmetric preparation of enantioenriched ß2 -aryl amino acids, starting from commercially available enantiopure d- and l-serine esters. The mechanism and selectivity of the reaction was rationalized based on computational models.


Assuntos
Aminoácidos/química , Aziridinas/química , Paládio/química , Aminoácidos/síntese química , Catálise , Serina/química , Estereoisomerismo , Termodinâmica
9.
Org Lett ; 21(10): 3554-3557, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31058517

RESUMO

The first total synthesis of pactalactam was accomplished using substrate-controlled stereoselective aziridination and regioselective aziridine ring-opening to construct three continuous amino groups on an octasubstituted cyclopentane core. The cyclopentane framework was obtained by ring-closing metathesis and aldol coupling using a l-threonine-derived oxazoline compound. Cyclic urea formation, m-acetylphenyl group introduction by Chan-Lam coupling, and primary alcohol-selective acylation yielded the reported pactalactam structure. The presence of pactalactam in the fermentation broth of pactamycin-producing bacteria was also confirmed.


Assuntos
Álcoois/química , Aziridinas/química , Ciclopentanos/química , Imidazolidinas/síntese química , Pactamicina/síntese química , Acilação , Imidazolidinas/química , Estrutura Molecular , Pactamicina/química
10.
Org Lett ; 21(7): 2200-2203, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30855974

RESUMO

Lantibiotics are a class of peptide antibiotics with activity against most Gram-positive bacteria. Lanthionine (Lan) and ß-MeLan are unusual thioether-bridged, non-proteinogenic amino acids, which are characteristic features of lantibiotics. In this paper, we report the facile stereoselective synthesis of ß-methyllanthionines with orthogonal protection by nucleophilic ring opening of aziridines. This method leads to an expedient access to ß-methyllanthionines and allows production of over 30 g of ß-methyllanthionine in a single batch.


Assuntos
Alanina/análogos & derivados , Aminoácidos/química , Aziridinas/química , Bactérias Gram-Positivas/efeitos dos fármacos , Índio/química , Sulfetos/síntese química , Alanina/síntese química , Alanina/química , Bactérias Gram-Positivas/química , Estrutura Molecular , Sulfetos/química
11.
Org Biomol Chem ; 17(15): 3797-3804, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30916695

RESUMO

Herein, we have presented a facile and efficient method of ring-opening nucleophilic fluorination of aziridines, affording highly regio-selective ß-fluorinated amines. Firstly, the example of ring-opening hydrofluorination of azetidines was reported. Then, the Olah's reagent also provided a promising method for the construction of enantioenriched ß-fluoro-α-amino acid derivatives, which could be used for the preparation of peptide-based bioactive molecules.


Assuntos
Aminas/síntese química , Aminoácidos/química , Azetidinas/química , Aziridinas/química , Aminas/química , Halogenação , Estrutura Molecular , Estereoisomerismo
12.
Org Lett ; 21(6): 1926-1929, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30821980

RESUMO

Cu(II)-mediated direct NH2 and NH alkyl aryl aminations and olefin aziridinations are described. These room-temperature, one-pot, environmentally friendly procedures replace costly Rh2 catalysts and, in some instances, display important differences with comparable Rh2- and Fe-supported reactions.


Assuntos
Alcenos/química , Aziridinas/química , Cobre/química , Alcenos/síntese química , Aminação , Aziridinas/síntese química , Catálise , Estrutura Molecular
13.
Molecules ; 24(3)2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30754666

RESUMO

Small ring heterocycles, such as epoxides and aziridines, are present in several natural products and are also highly versatile building blocks, frequently involved in the synthesis of numerous bioactive products and pharmaceuticals. Because of the potential for increased efficiency and selectivity, along with the advantages of environmentally benign synthetic procedures, multicomponent reactions (MCRs) have been explored in the synthesis and ring opening of these heterocyclic units. In this review, the recent advances in MCRs involving the synthesis and applications of epoxides and aziridines to the preparation of other heterocycles are discussed emphasizing the stereoselectivity of the reactions.


Assuntos
Aziridinas/síntese química , Compostos de Epóxi/síntese química , Aziridinas/química , Produtos Biológicos/química , Compostos de Epóxi/química , Química Verde , Estrutura Molecular , Estereoisomerismo
14.
Eur J Pharm Sci ; 127: 217-224, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30414836

RESUMO

Directed enzyme prodrug therapy is a chemotherapy strategy that utilises prodrug-activating enzymes to activate prodrugs at the tumour location, thus reducing off-target effects. The most commonly investigated enzyme for use with the CB1954 prodrug is the NfnB nitroreductase from E. coli. Literature states that CB1954 is reduced by NfnB at the 2- or 4-position at a 1:1 ratio; deviation from this ratio has been observed in the literature, but not further investigated. The kinetic parameters for the genetically-modified enzymes; NfnB-his, NfnB-cys and AuNP-NfnB-cys were assessed and HPLC analysis was used to determine the hydroxylamine product ratios formed when reacted with CB1954. Time-dependent HPLC studies were carried out to assess how this ratio changes over time. It was shown that the hydroxylamine ratio formed by the reduction of CB1954 by a nitroreductase changes over time and that this change in ratio relates directly to the kinetics of the reaction. Thus, the hydroxylamine ratio measured using HPLC at a given time point was not a true indication of the preference of the nitroreductase enzymes during catalysis. These results question how nitroreductases are evaluated in terms of the hydroxylamine ratio and it is suspected that this phenomenon may also apply to other enzyme/prodrug combinations.


Assuntos
Antineoplásicos/química , Aziridinas/química , Hidroxilamina/química , Nitrorredutases/química , Pró-Fármacos/química , Cromatografia Líquida de Alta Pressão , Oxirredução
15.
Curr Med Chem ; 26(4): 648-663, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29473492

RESUMO

Heterocyclic compounds containing nitrogen ions, like pyrazoles, aziridines, diaziridines and their metal ion complexes with Cu(II), Zn(II) and Ru(III) and others exhibit a wide range of biological activity, including mainly anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. Biological significance of these molecules and thus their potential use in medicine has driven growing interest into their coordination chemistry. A knowledge of the relationship between the structure of chemical compounds and their activity is needed for the synthesis of the preparations possessing the most beneficial features. The choice of interposed substituents may improve biocidal and antitumor action, reduce the toxicity of the initial substance, or even completely eliminate its adverse effects for healthy tissues. The main aim of this review paper is to present the current state of knowledge concerning the synthesis and biological activity of complexes with small heterocyclic ligands containing transition metal ions.


Assuntos
Aziridinas/química , Complexos de Coordenação/síntese química , Pirazóis/química , Elementos de Transição/química , Anti-Infecciosos/síntese química , Anti-Inflamatórios/síntese química , Antineoplásicos/síntese química , Antioxidantes/síntese química , Descoberta de Drogas/métodos , Humanos , Íons/química , Ligantes , Estrutura Molecular , Relação Estrutura-Atividade
16.
Org Lett ; 20(24): 8082-8085, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30532977

RESUMO

Reactions of thermally generated benzynes with diaziridines are reported. These trapping reactions follow the same pathway as reported earlier by Heine and co-workers with electron-deficient alkynes. The resulting N-arylhydrazones were obtained efficiently in a single step. The preference for the mode of addition of the nucleophilic diaziridine nitrogen atom to the more electrophilic benzyne carbon was consistent with what is predicted on the basis of distortion analysis. The feasibility of converting the hydrazone into a Fisher-indole adduct was demonstrated.


Assuntos
Aziridinas/química , Derivados de Benzeno/química , Hidrazonas/síntese química , Hidrazonas/química , Estrutura Molecular
17.
Org Lett ; 20(24): 8064-8068, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30525689

RESUMO

A method for the primary electrophilic amination of primary, secondary, and tertiary organometallic substrates from a bench-stable NH-oxaziridine reagent is described. This facile and highly chemoselective transformation occurs at ambient temperature and without transition metal catalysts or purification by column chromatography to provide alkylamine products in a single step. Density functional theory (DFT) calculations revealed that, despite the basicity of alkylmetals, the direct NH-transfer pathway is favored over proton and O-transfer.


Assuntos
Aminas/síntese química , Aziridinas/química , Compostos Organometálicos/química , Aminação , Aminas/química , Teoria da Densidade Funcional , Conformação Molecular
18.
Org Lett ; 20(23): 7571-7575, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30387610

RESUMO

Catalytic ring-opening phosphonation and phosphatation of vinyl aziridines have been developed in a regiodivergent fashion, giving linear and branched products. Generation of P-centered radicals enables SN2'-type ring-opening reactions of vinyl aziridines to afford δ-amino alkylphosphorus products at room temperature. On the other hand, in situ generated phosphate anions via the Ag-catalyzed aerobic oxidation of phosphonyl reactants underwent SN2 reaction to provide branched phosphorus-containing amine products. Furthermore, this divergent methodology serves as a powerful tool for the stereospecific synthesis of phosphorus-containing amino acid derivatives.


Assuntos
Aminoácidos/síntese química , Aziridinas/química , Fósforo/química , Aminoácidos/química , Estrutura Molecular , Estereoisomerismo
19.
Chemistry ; 24(71): 19081-19088, 2018 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-30307091

RESUMO

Cyclophellitol aziridines are potent irreversible inhibitors of retaining glycosidases and versatile intermediates in the synthesis of activity-based glycosidase probes (ABPs). Direct 3-amino-2-(trifluoromethyl)quinazolin-4(3H)-one-mediated aziridination of l-ido-configured cyclohexene has enabled the synthesis of new covalent inhibitors and ABPs of α-l-iduronidase, deficiency of which underlies the lysosomal storage disorder mucopolysaccharidosis type I (MPS I). The iduronidase ABPs react covalently and irreversibly in an activity-based manner with human recombinant α-l-iduronidase (rIDUA, Aldurazyme® ). The structures of IDUA when complexed with the inhibitors in a non-covalent transition state mimicking form and a covalent enzyme-bound form provide insights into its conformational itinerary. Inhibitors 1-3 adopt a half-chair conformation in solution (4 H3 and 3 H4 ), as predicted by DFT calculations, which is different from the conformation of the Michaelis complex observed by crystallographic studies. Consequently, 1-3 may need to overcome an energy barrier in order to switch from the 4 H3 conformation to the transition state (2, 5 B) binding conformation before reacting and adopting a covalent 5 S1 conformation. rIDUA can be labeled with fluorescent Cy5 ABP 2, which allows monitoring of the delivery of therapeutic recombinant enzyme to lysosomes, as is intended in enzyme replacement therapy for the treatment of MPS I patients.


Assuntos
Aziridinas/química , Cicloexanóis/química , Inibidores Enzimáticos/química , Iduronidase/antagonistas & inibidores , Iduronidase/análise , Cromatografia Líquida , Ensaios Enzimáticos , Corantes Fluorescentes/química , Humanos , Microscopia de Fluorescência , Modelos Moleculares , Proteínas Recombinantes/análise , Coloração e Rotulagem , Espectrometria de Massas em Tandem
20.
Molecules ; 23(10)2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30332802

RESUMO

Oxaziridines have emerged as powerful and elegant oxygen- and nitrogen-transfer agents for a broad array of nucleophiles, due to the remarkably high and tunable reactivities. However, the asymmetric catalysis involving oxaziridines is still in its infancy. Herein, this review aims to examine recent advances in the catalytic asymmetric transformations of oxaziridines, including oxidation, amination, cycloaddition and deracemization.


Assuntos
Aziridinas/química , Aminação , Catálise , Reação de Cicloadição , Estrutura Molecular
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