Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Diabetes Metab ; 50(1): 101501, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38061425

RESUMO

OBJECTIVE: To assess real-world safety and effectiveness of dapagliflozin in people living with type 1 diabetes mellitus (T1DM). METHODS: We conducted a multicenter retrospective study in Spain including data from 250 people living with T1DM receiving dapagliflozin as add-on therapy to insulin (80.8 % on-label use). The number of diabetic ketoacidosis (DKA) events was calculated over a 12-month follow-up (primary outcome). Changes in body weight, HbA1c, total daily insulin dose, and continuous glucose monitoring (CGM) metrics from baseline (at dapagliflozin prescription) to 12 months were also evaluated. RESULTS: A total of five DKA events (2.4 % [95 % CI 0.3;4.5] were reported in patients with a 12-month follow-up, n = 207): two events related to insulin pump malfunction, two events related to concomitant illnesses, and one event related to insulin dose omission. DKA events were more frequent among insulin pump users than among participants on multiple daily injections (7.7 % versus 1.2 %). Four of the reported DKA events occurred within the first six months after initiation of dapagliflozin. No deaths or persistent sequelae due to DKA were reported. No severe hypoglycemia episodes were reported. Significant reductions in mean body weight (-3.3 kg), HbA1c (-0.6 %), and total daily insulin dose (-8.6 %), P < 0.001, were observed 12 months after dapagliflozin prescription. Significant improvements in TIR (+9.3 %), TAR (-7.2 %), TBR (-2.5 %), and coefficient of variation (-5.1 %), P < 0.001, were also observed in the subgroup of patients with available CGM data. Finally, an improvement in urinary albumin-to-creatinine ratio (UACR) was found among participants with UACR ≥ 30 mg/g at baseline (median decrease of 99 mg/g in UACR, P = 0.001). CONCLUSION: The use of dapagliflozin in people living with T1DM has an appropriate safety profile after careful selection of participants and implementation of strategies to reduce the risk of DKA (i.e., prescribed according to the recommendations of the European Medicines Agency), and also leads to clinical improvements in this population.


Assuntos
Diabetes Mellitus Tipo 1 , Cetoacidose Diabética , Glucosídeos , Humanos , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/epidemiologia , Hipoglicemiantes/efeitos adversos , Estudos Retrospectivos , Hemoglobinas Glicadas , Glicemia , Automonitorização da Glicemia , Espanha/epidemiologia , Compostos Benzidrílicos/efeitos adversos , Insulina/uso terapêutico , Peso Corporal , Cetoacidose Diabética/tratamento farmacológico
2.
Org Lett ; 26(14): 2800-2805, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37931032

RESUMO

The acid mediated ortho-iodination of Weinreb amides using a readily available catalyst is described. The selective ortho-iodination of Weinreb amides, challenging substrates in directed C-H activations, and also of benzamides is achieved. The process works under mild conditions and tolerates air and moisture, having a great potential for industrial applications. The methodology can be applied under mechanochemical conditions maintaining the reaction outcome and selectivity.

3.
Org Lett ; 25(30): 5608-5612, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37486803

RESUMO

A novel procedure for the synthesis of α,α-diaryl-α-amino acid derivatives has been developed. Silver oxide catalyzes the conjugate addition of α-aryl isocyanoacetates to o-quinone diimide, affording the corresponding α,α-diarylisocyano esters in excellent yields and regioselectivities in short reaction times. Acid hydrolysis of the isocyano group provides the corresponding amino acids bearing a diarylated tetrasubstituted carbon atom. The reaction is also amenable to the synthesis of α-alkyl-α-arylisocyano esters, while the reaction with 3-hydroxy o-quinone diimides provides 4H-benzo[e][1,3]oxazines via a conjugate addition/cyclization process.

4.
Org Biomol Chem ; 21(2): 345-350, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36484719

RESUMO

A Cu(II)/BOX complex catalyses the enantioselective addition of difluorinated silyl enol ethers to acylpyridine N-oxides. The reaction provides difluorinated chiral tertiary alcohols of great interest in medicinal chemistry. These compounds are obtained in moderate to excellent yields and with high enantioselectivities. The stereochemical outcome of the reaction has been explained by DFT calculations.


Assuntos
Éteres , Óxidos , Éteres/química , Estereoisomerismo , Estrutura Molecular , Álcoois , Catálise
5.
Org Biomol Chem ; 20(43): 8395-8399, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36239232

RESUMO

An efficient organocatalytic asymmetric Mannich reaction between isoxazol-5(4H)-ones and isatin-derived ketimines has been developed. A bifunctional squaramide/Brønsted base organocatalyst catalyzed the enantioselective Mannich addition to afford chiral 3-aminooxindoles bearing a tetrasubstituted stereocenter at C3 decorated with an isoxazole moiety in good yields and with excellent enantioselectivities. Additionally, several synthetic transformations were described showing the versatility of the prepared compounds.


Assuntos
Isatina , Estereoisomerismo , Estrutura Molecular , Catálise
6.
Chemistry ; 28(44): e202201000, 2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35638139

RESUMO

In this paper, we present an unprecedented and general umpolung protocol that allows the functionalization of silyl enol ethers and of 1,3-dicarbonyl compounds with a large range of heteroatom nucleophiles, including carboxylic acids, alcohols, primary and secondary amines, azide, thiols, and also anionic carbamates derived from CO2 . The scope of the reaction also extends to carbon-based nucleophiles. The reaction relies on the use of 1-bromo-3,3-dimethyl-1,3-dihydro-1λ3 [d][1,2]iodaoxole, which provides a key α-brominated carbonyl intermediate. The reaction mechanism has been studied experimentally and by DFT, and we propose formation of an unusual enolonium intermediate with a halogen-bonded bromide.

7.
Org Lett ; 24(11): 2149-2154, 2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-35293212

RESUMO

The diastereo- and enantioselective dearomative formal [3 + 2] cycloaddition of 2-nitrobenzofurans and α-aryl-α-isocyanoacetate esters provides tricyclic compounds bearing the 3a,8b-dihydro-1H-benzofuro[2,3-c]pyrrole framework with three consecutive stereogenic centers. The reaction was enabled by a cupreine-ether organocatalyst. The reaction products were obtained with almost full diastereoselectivity and with excellent enantiomeric excesses for a number of substituted 2-nitrobenzofurans and isocyanoacetates.


Assuntos
Ésteres , Benzofuranos , Catálise , Reação de Cicloadição , Estereoisomerismo
8.
Open Respir Arch ; 4(4): 100202, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-37496970

RESUMO

Background and aim: Since their effectiveness was initially demonstrated, oral corticosteroids (OCS) have been routinely used to treat asthma. We now know that their usage is linked to the development of side effects such osteoporosis and adrenal insufficiency. This is an observational study based on Delphi methodology. The questionnaire was divided into 4 sections: OCS generalities, maintenance treatment, short-term treatment, and adverse events. Materials and methods: Two rounds of a 68-item questionnaire were completed by a panel of 48 allergists and pneumologists. Results: Definitions were agreed upon, as was the proper use of OCS in the treatment of severe asthma. The experts agreed that the use of OCS should be minimized as much as possible and that in the event of maintenance treatments, a slow and progressive tapering strategy should be used. They also emphasized the importance of standardizing the technique for measuring the amount of SCG delivered in both cases. Conclusions: This consensus document attempts to bring together scientifically supported suggestions from specialists in the management of asthma to reduce the use of OCS in Spain.

9.
Chemistry ; 26(65): 14978-14986, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32757212

RESUMO

We have used experimental studies and DFT calculations to investigate the IrIII -catalyzed isomerization of allylic alcohols into carbonyl compounds, and the regiospecific isomerization-chlorination of allylic alcohols into α-chlorinated carbonyl compounds. The mechanism involves a hydride elimination followed by a migratory insertion step that may take place at Cß but also at Cα with a small energy-barrier difference of 1.8 kcal mol-1 . After a protonation step, calculations show that the final tautomerization can take place both at the Ir center and outside the catalytic cycle. For the isomerization-chlorination reaction, calculations show that the chlorination step takes place outside the cycle with an energy barrier much lower than that for the tautomerization to yield the saturated ketone. All the energies in the proposed mechanism are plausible, and the cycle accounts for the experimental observations.

10.
Chem Commun (Camb) ; 56(66): 9461-9464, 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32677641

RESUMO

The enantioselective 1,4-alkynylation of conjugated imines derived from saccharin with aryl- and alkyl-substituted terminal alkynes has been achieved. The reaction mediated by diethylzinc in the presence of a catalytic amount of a bis(hydroxy)malonamide chiral ligand provides the corresponding imines bearing a propargylic stereocenter with moderate yields and fair to excellent enantioselectivities.


Assuntos
Iminas/química , Sacarina/química , Zinco/química , Catálise , Cristalografia por Raios X , Iminas/síntese química , Ligantes , Conformação Molecular , Estereoisomerismo
11.
Org Lett ; 22(14): 5380-5384, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32585111

RESUMO

A straightforward strategy for the synthesis of unprecedented α-aminoperoxides bearing primary and secondary alkylperoxide substituents is described. Commercially available dialkylzinc reagents are oxidized with molecular oxygen and the consequent peroxide species react with stable (hetero)aromatic and aliphatic α-amido sulfones in excellent yields (>90%). The now available α-aminoperoxides are of potential interest in medicinal chemistry, specifically for the synthesis of antimalarial compounds. Moreover, modification of the reaction conditions selectively leads to N,O-acetals in good yields.

12.
Org Lett ; 22(11): 4123-4128, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32383608

RESUMO

A regioselective protocol for the synthesis of substituted allylic chlorides, bromides, and fluorides has been established. Remarkably, the method can be applied to the enantioselective synthesis of challenging chiral allylic chlorides. When the allylic halides are treated with the base triazabicyclodecene as the catalyst, a [1,3]-proton shift takes place, giving the corresponding vinyl halides in excellent yields with excellent Z:E ratios. Furthermore, the [1,3]-proton shift takes place with an outstanding level of chirality transfer from chiral allylic alcohols (≤98%) to give chiral trifluoromethylated vinyl chlorides.

13.
Nat Commun ; 10(1): 5244, 2019 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748504

RESUMO

The selective synthesis of α-functionalized ketones with two similar enolizable positions can be accomplished using allylic alcohols and iridium(III) catalysts. A formal 1,3-hydrogen shift on allylic alcohols generates catalytic iridium-enolates in a stereospecific manner, which are able to react with electrophiles to yield α-functionalized ketones as single constitutional isomers. However, the employment of nucleophiles to react with the nucleophilic catalytic enolates in this chemistry is still unknown. Herein, we report an umpolung strategy for the selective synthesis of α-alkoxy carbonyl compounds by the reaction of iridium enolates and alcohols promoted by an iodine(III) reagent. Moreover, the protocol also works in an intramolecular fashion to synthesize 3(2H)-furanones from γ-keto allylic alcohols. Experimental and computational investigations have been carried out, and mechanisms are proposed for both the inter- and intramolecular reactions, explaining the key role of the iodine(III) reagent in this umpolung approach.

14.
Org Lett ; 21(11): 4063-4066, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31090430

RESUMO

Chiral cyclic ureas (2-imidazolinones) were prepared by the reaction of nitrones and isocyanoacetate esters using a multicatalytic system that combines a bifunctional Brønsted base-squaramide organocatalyst and Ag+ as a Lewis acid. The reaction could be achieved with a range of nitrones derived from aryl- and cycloalkylaldehydes with moderate diastereo- and good enantioselectivity. A plausible mechanism involving an initial formal [3 + 3] cycloaddition of the nitrone and isocyanoacetate ester, followed by rearrangement to an aminoisocyanate and cyclization to the imidazolinone, is proposed.

15.
J Org Chem ; 84(1): 314-325, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30537821

RESUMO

The first enantioselective formal [3 + 2] cycloaddition between α-isocyanoesters and trifluoromethylketones to give 5-trifluoromethyl-2-oxazolines bearing two contiguous stereogenic centers, one of them being a quaternary stereocenter substituted with a CF3 group, has been developed. The reaction is based upon a multicatalytic approach that combines a bifunctional Brønsted base-squaramide organocatalyst and Ag+ as Lewis acid. The reaction could be achieved with a range of aryl and heteroaryl trifluoromethyl ketones, and the resulting oxazolines were obtained with good to excellent diastereo- and enantioselectivity.

16.
Chemistry ; 24(45): 11564-11567, 2018 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-29928782

RESUMO

The first method to access unsymmetrical aliphatic acyloins is presented. The method relies on a fast 1,3-hydride shift mediated by an IrIII complex in allylic alcohols followed by oxidation with TEMPO+ . The direct conversion of allylic alcohols into acyloins is achieved in a one-pot procedure. Further functionalization of the Cα' of the α-amino-oxylated ketone products gives access to highly functionalized unsymmetrical aliphatic ketones, which further highlights the utility of this transformation.

17.
Chem Commun (Camb) ; 54(23): 2862-2865, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29488994

RESUMO

A multicatalytic approach that combines a bifunctional Brønsted base-squaramide organocatalyst and Ag+ as Lewis acid has been applied in the reaction of unactivated ketones with tert-butyl isocyanoacetate to give chiral oxazolines bearing a quaternary stereocenter. The formal [3+2] cycloaddition provided high yields of the corresponding cis-oxazolines with good diastereoselectivity and excellent enantioselectivity, being applied to aryl-alkyl and alkyl-alkyl ketones.

18.
J Am Chem Soc ; 138(40): 13408-13414, 2016 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-27636591

RESUMO

A mild base-catalyzed strategy for the isomerization of allylic alcohols and allylic ethers has been developed. Experimental and computational investigations indicate that transition metal catalysts are not required when basic additives are present. As in the case of using transition metals under basic conditions, the isomerization catalyzed solely by base also follows a stereospecific pathway. The reaction is initiated by a rate-limiting deprotonation. Formation of an intimate ion pair between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylic ethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.

19.
Ecotoxicology ; 25(10): 1730-1738, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27640016

RESUMO

The toxicity of Bacillus thuringiensis var. israelensis on zooplanktonic microcrustaceans was evaluated using individuals collected in coastal wetlands where this larvicide has been used for mosquito control over the last decades. We tested five zooplankton species that coexist with mosquito larvae: two copepods (both nauplii and adults of Tropocyclops prasinus and Acantocyclops americanus), and three cladocerans (Ceriodaphnia reticulata, Chydorus sphaericus, and Daphnia cf. pulex). Our experiments included seven replicates of six concentrations (Bti Vectobac12AS 1200 Bti ITU/mg): 0, 5, 25, 50, 250, and 500 mg L-1. We analyzed acute and sub-chronic effects after a single inoculation. Despite the high variability of responses among our tested organisms, we found a general pattern of increasing mortality with concentration and time. We conclude that negative effects at the community level are not unlikely as some species were affected at doses close to those used in field applications.


Assuntos
Crustáceos/efeitos dos fármacos , Inseticidas/toxicidade , Controle Biológico de Vetores , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Bacillus thuringiensis , Controle de Mosquitos , Áreas Alagadas
20.
Acta otorrinolaringol. esp ; 67(4): 187-192, jul.-ago. 2016. graf
Artigo em Espanhol | IBECS | ID: ibc-154415

RESUMO

Introducción: Los acúfenos subjetivos, a pesar del tiempo transcurrido desde que fueron descritos por primera vez, continúan sin tener un tratamiento con eficacia demostrada. El objetivo de este artículo es valorar la eficacia de la terapia cognitiva-conductual en el tratamiento de estos enfermos. Pacientes y métodos: Durante un periodo de tiempo de los años 2012-2013 se estudia a 310 enfermos que presentaban acúfenos subjetivos. De ellos, 267 fueron incluidos en un tratamiento basado en terapia cognitiva-conductual. El periodo de seguimiento fue de 18 meses y en 11 enfermos de 21 meses. Resultados: Considerando los enfermos que interrumpieron el tratamiento como fracasos, el porcentaje de curación fue de 95,7%. Conclusión: La terapia cognitiva-conductual debe estar siempre incluida en el tratamiento de los enfermos de acúfenos (AU)


Introduction: It has been a long time since subjective tinnitus cases were described for the first time but they still lack a treatment with proven effectiveness. The main goal of this study was to evaluate the effectiveness of cognitive behavioural therapy in these patients. Patients and method: Between 2012 and 2013, 310 patients that suffered from subjective tinnitus were studied. Of these, 267 were included in treatment based on cognitive behavioural therapy. The monitoring period lasted 18 months for most cases, while it lasted 21 months for 11 patients. Results: Considering patients that interrupted their treatment as failures, the percentage of recovery was 95.7%. Conclusion: Cognitive behavioural therapy should always be included in the treatment of people suffering from tinnitus (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Zumbido/diagnóstico , Zumbido/psicologia , Terapia Cognitivo-Comportamental/métodos , Terapia Cognitivo-Comportamental/tendências , Entrevista Psicológica/métodos , Audiometria/métodos , Audiometria , Resultado do Tratamento , Avaliação de Eficácia-Efetividade de Intervenções , Medicina Psicossomática/métodos , Medicina Psicossomática/tendências
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...