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1.
N Engl J Med ; 388(23): 2145-2158, 2023 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-36972026

RESUMEN

BACKGROUND: Dostarlimab is an immune-checkpoint inhibitor that targets the programmed cell death 1 receptor. The combination of chemotherapy and immunotherapy may have synergistic effects in the treatment of endometrial cancer. METHODS: We conducted a phase 3, global, double-blind, randomized, placebo-controlled trial. Eligible patients with primary advanced stage III or IV or first recurrent endometrial cancer were randomly assigned in a 1:1 ratio to receive either dostarlimab (500 mg) or placebo, plus carboplatin (area under the concentration-time curve, 5 mg per milliliter per minute) and paclitaxel (175 mg per square meter of body-surface area), every 3 weeks (six cycles), followed by dostarlimab (1000 mg) or placebo every 6 weeks for up to 3 years. The primary end points were progression-free survival as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, and overall survival. Safety was also assessed. RESULTS: Of the 494 patients who underwent randomization, 118 (23.9%) had mismatch repair-deficient (dMMR), microsatellite instability-high (MSI-H) tumors. In the dMMR-MSI-H population, estimated progression-free survival at 24 months was 61.4% (95% confidence interval [CI], 46.3 to 73.4) in the dostarlimab group and 15.7% (95% CI, 7.2 to 27.0) in the placebo group (hazard ratio for progression or death, 0.28; 95% CI, 0.16 to 0.50; P<0.001). In the overall population, progression-free survival at 24 months was 36.1% (95% CI, 29.3 to 42.9) in the dostarlimab group and 18.1% (95% CI, 13.0 to 23.9) in the placebo group (hazard ratio, 0.64; 95% CI, 0.51 to 0.80; P<0.001). Overall survival at 24 months was 71.3% (95% CI, 64.5 to 77.1) with dostarlimab and 56.0% (95% CI, 48.9 to 62.5) with placebo (hazard ratio for death, 0.64; 95% CI, 0.46 to 0.87). The most common adverse events that occurred or worsened during treatment were nausea (53.9% of the patients in the dostarlimab group and 45.9% of those in the placebo group), alopecia (53.5% and 50.0%), and fatigue (51.9% and 54.5%). Severe and serious adverse events were more frequent in the dostarlimab group than in the placebo group. CONCLUSIONS: Dostarlimab plus carboplatin-paclitaxel significantly increased progression-free survival among patients with primary advanced or recurrent endometrial cancer, with a substantial benefit in the dMMR-MSI-H population. (Funded by GSK; RUBY ClinicalTrials.gov number, NCT03981796.).


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Endometriales , Recurrencia Local de Neoplasia , Femenino , Humanos , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carboplatino/administración & dosificación , Carboplatino/efectos adversos , Reparación de la Incompatibilidad de ADN , Método Doble Ciego , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/genética , Neoplasias Endometriales/mortalidad , Neoplasias Endometriales/patología , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Inestabilidad de Microsatélites , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/etiología , Paclitaxel/administración & dosificación , Paclitaxel/efectos adversos
2.
Plant Cell Physiol ; 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38907526

RESUMEN

Cyanobacteria play a key role in primary production in both oceans and fresh waters and hold great potential for sustainable production of a large number of commodities. During their life, cyanobacteria cells need to acclimate to a multitude of challenges, including shifts in intensity and quality of incident light. Despite our increasing understanding of metabolic regulation under various light regimes, detailed insight into fitness advantages and limitations under shifting light quality remains underexplored. Here, we study photo-physiological acclimation in the cyanobacterium Synechocystis sp. PCC 6803 throughout the photosynthetically active radiation (PAR) range. Using light emitting diodes (LEDs) with qualitatively different narrow spectra, we describe wavelength dependence of light capture, electron transport and energy transduction to main cellular pools. In addition, we describe processes that fine-tune light capture, such as state transitions, or the efficiency of energy transfer from phycobilisomes to photosystems (PS). We show that growth was the most limited under blue light due to inefficient light harvesting, and that many cellular processes are tightly linked to the redox state of the plastoquinone (PQ) pool, which was the most reduced under red light. The PSI-to-PSII ratio was low under blue photons, however, it was not the main growth-limiting factor, since it was even more reduced under violet and near far-red lights, where Synechocystis grew faster compared to blue light. Our results provide insight into the spectral dependence of phototrophic growth and can provide the foundation for future studies of molecular mechanisms underlying light acclimation in cyanobacteria, leading to light optimization in controlled cultivations.

3.
Gynecol Oncol ; 186: 35-41, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38569327

RESUMEN

OBJECTIVE: Fertility-sparing surgery (FSS) aims to achieve oncological outcomes that are non-inferior to radical treatment while preserving fertility and optimizing reproductive results. This study assesses in vitro fertilization (IVF) outcomes in early-stage cervical cancer survivors following FSS, comparing radical and non-radical approaches. METHODS: This retrospective analysis used data from Hungary's National Health Insurance Fund (2004-2022) on patients who underwent IVF treatment following FSS for early-stage cervical cancer at ten Hungarian fertility clinics. Patients were classified into radical and non-radical surgical groups, with the uterine arteries being spared in the non-radical procedures. RStudio (R software version: 4.2.2) was used for statistical analysis. Student's t-test was used to compare group means, and Fisher's exact test was applied to assess independence and distributions between categorical variables, and to estimate odds. RESULTS: The study analyzed data from 122 IVF treatment cycles involving 36 patients. The non-radical group had a significantly higher live birth rate (83%, 5/6 compared to the radical group (17%, 5/30). Additionally, the non-radical group had a significantly higher implantation rate and cumulative live birth rate per oocyte retrieval (37%, 7/19 and 55%, 6/11 respectively) compared to the radical group (8%, 12/148 and 6%, 5/80 respectively). CONCLUSION: This is the largest study to evaluate IVF outcomes in young cervical cancer survivors who have undergone FSS. The findings suggest that less radical procedures are associated with significantly better IVF outcomes. These results emphasize the importance of considering oncological safety and reproductive outcomes together when choosing FSS for early-stage cervical cancer patients. It also highlights the reproductive benefits of performing less radical surgery.


Asunto(s)
Preservación de la Fertilidad , Fertilización In Vitro , Neoplasias del Cuello Uterino , Humanos , Femenino , Neoplasias del Cuello Uterino/cirugía , Neoplasias del Cuello Uterino/patología , Estudios Retrospectivos , Adulto , Preservación de la Fertilidad/métodos , Preservación de la Fertilidad/estadística & datos numéricos , Embarazo , Fertilización In Vitro/métodos , Estadificación de Neoplasias , Hungría , Tratamientos Conservadores del Órgano/métodos , Tratamientos Conservadores del Órgano/estadística & datos numéricos
4.
Chem Rec ; 23(9): e202300083, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37129578

RESUMEN

Synthesis and applications of fluoroalkyl and fluoroalkenyliodonium salts are summarized in this account article, focusing preferably to the reagents designed in our laboratory in the last decade. Among these reagents trifluoroethyl(aryl)iodonium salts have been used most frequently to build carbon-carbon and carbon-heteroatom bonds in simple nucleophilic substitutions and through transition metal catalyzed coupling reactions. Iodonium salts equipped with unsaturated fluorinated function showed diverse reactivity due to their electron deficient character, and these molecular motifs enable cycloadditions and nucleophilic additions to prepare fluorinated carbo- and heterocyclic molecules. Beyond the overview of existing transformations, with the presented collection, we aim to inspire future developments of iodonium reagents and their application in organic synthesis.

5.
Am J Obstet Gynecol ; 228(4): 443.e1-443.e10, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36427596

RESUMEN

BACKGROUND: Fertility-sparing treatment in patients with cervical cancer should, in principle, follow identical algorithms to that in patients without future reproductive plans. In recent years, a trend toward nonradical procedures, such as conization or simple trachelectomy, has become apparent in medical literature, because of their associations with better pregnancy outcomes. However, the published reports included small numbers of patients and heterogenous treatment strategies to ascertain the safety of such approaches. OBJECTIVE: This study aimed to collect multi-institutional data regarding the oncological outcomes after fertility-sparing treatment in patients with cervical cancer and to identify prognostic risk factors, including the influence of the radicality of individual cervical procedures. STUDY DESIGN: Patients aged 18 to 40 years with International Federation of Gynecology and Obstetrics 2018 stage IA1 with positive lymphovascular space invasion or ≥IA2 cervical cancer who underwent any type of fertility-sparing procedure were eligible for this retrospective observational study, regardless of their histotype, tumor grade, and history of neoadjuvant chemotherapy. Associations between disease- and treatment-related characteristics with the risk of recurrence were analyzed. RESULTS: A total of 733 patients from 44 institutions across 13 countries were included in this study. Almost half of the patients had stage IB1 cervical cancer (49%), and two-thirds of patients were nulliparous (66%). After a median follow-up of 72 months, 51 patients (7%) experienced recurrence, of whom 19 (2.6%) died because of the disease. The most common sites of recurrence were the cervix (53%) and pelvic nodes (22%). The risk of recurrence was 3 times higher in patients with tumors >2 cm in size than in patients with smaller tumors, irrespective of the treatment radicality (19.4% vs 5.7%; hazard ratio, 2.982; 95% confidence interval, 1.383-6.431; P=.005). The recurrence risk in patients with tumors ≤2 cm in size did not differ between patients who underwent radical trachelectomy and patients who underwent nonradical (conization and simple trachelectomy) cervical procedures (P=.957), regardless of tumor size subcategory (<1 or 1-2 cm) or lymphovascular space invasion. CONCLUSION: Nonradical fertility-sparing cervical procedures were not associated with an increased risk of recurrence compared with radical procedures in patients with tumors ≤2 cm in size in this large, multicenter retrospective study. The risk of recurrence after any type of fertility-sparing procedure was significantly greater in patients with tumors >2 cm in size.


Asunto(s)
Preservación de la Fertilidad , Neoplasias del Cuello Uterino , Embarazo , Femenino , Humanos , Neoplasias del Cuello Uterino/cirugía , Neoplasias del Cuello Uterino/patología , Estudios Retrospectivos , Cuello del Útero/cirugía , Cuello del Útero/patología , Preservación de la Fertilidad/métodos , Resultado del Embarazo , Factores de Riesgo , Estadificación de Neoplasias
6.
Environ Res ; 238(Pt 2): 117283, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37783333

RESUMEN

Climate change threatens surface waters worldwide, especially shallow lakes where one of the expected consequences is a sharp increase in their water temperatures. Phytobenthos is an essential, but still less studied component of aquatic ecosystems, and it would be important to learn more about how global warming will affect this community in shallow lakes. In this research, the effects of different climate change scenarios (SSP2-4.5 and SSP5-8.5, as intermediate and high emission scenarios) on the structure and function of the entire phytobenthos community using species- and trait-based approaches were experimentally investigated in an outdoor mesocosm system. Our results show that the forecasted 3 °C increase in temperature will already exert significant impacts on the benthic algal community by (1) altering its species and (2) trait composition (smaller cell size, lower abundance of colonial and higher of filamentous forms); (3) decreasing Shannon diversity; and (4) enhancing the variability of the community. Higher increase in the temperature (+5 °C) will imply more drastic alterations in freshwater phytobenthos by (1) inducing very high variability in species composition and compositional changes even in phylum level (towards higher abundance of Cyanobacteria and Chlorophyta at the expense of Bacillariophyta); (2) continuing shift in trait composition (benefits for smaller cell volume, filamentous life-forms, non-motile and weakly attached taxa); (3) further reducing the functional diversity; (4) increasing biofilm thickness (1.4 µm/°C) and (5) decreasing maximum quantum yield of photosystem II. In conclusion, already the intermediate emission scenario will predictably induce high risk in biodiversity issues, the high emission scenario will imply drastic impacts on the benthic algae endangering even the function of the ecosystem.


Asunto(s)
Cambio Climático , Lagos , Ecosistema , Calentamiento Global , Biodiversidad
7.
Chemistry ; 28(20): e202103967, 2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35019168

RESUMEN

DNA-encoded library (DEL) technology has become widely used in drug discovery research. The construction of DELs requires robust organic transformations that proceed in aqueous media under mild conditions. Unfortunately, the application of water as reaction medium for organic synthesis is not evident due to the generally limited solubility of organic reagents. However, the use of surfactants can offer a solution to this issue. Oil-in-water microemulsions formed by surfactant micelles are able to localize hydrophobic reagents inside them, resulting in high local concentrations of the organic substances in an otherwise poorly solvated environment. This review provides a conceptual and critical summary of micellar synthesis possibilities that are well suited to DEL synthesis. Existing examples of micellar DEL approaches, together with a selection of micellar organic transformations fundamentally suitable for DEL are discussed.


Asunto(s)
Micelas , Tensoactivos , ADN/química , Indicadores y Reactivos , Solubilidad , Tensoactivos/química , Agua
8.
Angew Chem Int Ed Engl ; 61(37): e202208420, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-35876269

RESUMEN

[1,2]-shift of atoms in alkyl fragments belongs to the class of dyotropic rearrangements. Various atoms, including halogens can be involved in the migration, however participation of iodine is unprecedented. Herein, we report our experimental and DFT studies on the oxidation triggered dyotropic rearrangement of iodo and chloro functions via butterfly-type transition state to demonstrate the migrating ability of λ3 -iodane centre. With the exploitation of dyotropic rearrangement we designed and synthesized a novel fluoroalkyl iodonium reagent from industrial feedstock gas HFO-1234yf. We demonstrated that the hypervalent reagent serves as an excellent fluoroalkylation agent for various amines and nitrogen heterocycles.

9.
Chemistry ; 27(63): 15638-15643, 2021 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-34549840

RESUMEN

The availability and synthesis of fluorinated enamine derivatives such as N-(3,3,3-trifluoropropenyl)heterocycles are challenging, especially through direct functionalization of the heterocyclic scaffold. Herein, a stereoselective N-trifluoropropenylation method based on the use of a bench-stable trifluoropropenyl iodonium salt is described. This reagent enables the straightforward trifluoropropenylation of various N-heterocycles under mild reaction conditions, providing trifluoromethyl enamine type moieties with high stereoselectivity and efficiency.


Asunto(s)
Compuestos Heterocíclicos , Indicadores y Reactivos
10.
Eur J Pediatr ; 179(5): 801-805, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31919579

RESUMEN

Bilastine, a second-generation antihistamine, is approved in Europe for the treatment of allergic rhinoconjunctivitis and urticaria in adults and children aged ≥ 6 years. Pharmacokinetic data for children aged 6-11 years were extracted post hoc from a study in which children (2-11 years) with allergic rhinoconjunctivitis or urticaria received oral bilastine (10 mg/day). Maximum plasma concentration (Cmax) and area under the plasma concentration curve (AUC) data were compared with adult pharmacokinetic data from seven clinical studies (bilastine 20 mg/day). Safety data for children aged 6-11 years were extracted post hoc from a phase III randomized controlled trial of children (2-11 years) with allergic rhinoconjunctivitis or chronic urticaria receiving once-daily bilastine 10 mg or placebo for 12 weeks. Exposure and Cmax values were similar for children (6-11 years) and adults: median pediatric/adult ratios for AUC0-24 and Cmax were 0.93 and 0.91, respectively. There was no significant difference in the incidence of treatment-emergent adverse in children (6-11 years) receiving bilastine 10 mg or placebo.Conclusion: Pharmacokinetic and safety analyses in children aged 6-11 years support the suitability of the pediatric dose of bilastine 10 mg and confirm that the safety profiles of bilastine and placebo are similar.What is Known:• Bilastine, a second-generation antihistamine, is approved in Europe for the treatment of allergic rhinoconjunctivitis and urticaria in adults (20 mg/day) and children aged ≥ 6 years (10 mg/day).• An ontogenic model based on adult data and pharmacokinetic/pharmacodynamic simulations supported the selection of a bilastine dose of 10 mg/day in children aged 2-11 years. Bilastine 10 mg/day was shown to have a safety profile similar to that of placebo in a large phase III randomized clinical trial in children aged 2-11 years.What is New:• As bilastine is approved in Europe for children aged ≥6 years, the current study reports the results of two post hoc analyses of pharmacokinetic and safety data in children aged 6-11 years.• Analysis of pharmacokinetic and safety data in children aged 6-11 years supports the suitability of the pediatric dose of bilastine 10 mg and confirms that its safety profile is similar to that of placebo.


Asunto(s)
Bencimidazoles/farmacocinética , Conjuntivitis Alérgica/tratamiento farmacológico , Antagonistas de los Receptores Histamínicos H1 no Sedantes/farmacocinética , Piperidinas/farmacocinética , Urticaria/tratamiento farmacológico , Administración Oral , Adulto , Bencimidazoles/administración & dosificación , Bencimidazoles/efectos adversos , Niño , Femenino , Antagonistas de los Receptores Histamínicos H1 no Sedantes/administración & dosificación , Antagonistas de los Receptores Histamínicos H1 no Sedantes/efectos adversos , Humanos , Masculino , Piperidinas/administración & dosificación , Piperidinas/efectos adversos
11.
Molecules ; 25(20)2020 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-33081411

RESUMEN

The trifluoromethylation of aromatic and heteroaromatic cores has attracted considerable interest in recent years due to its pharmacological relevance. We studied the extension of a simple copper-catalyzed trifluoromethylation protocol to alkoxy-substituted iodopyridines and their benzologs. The trifluoromethylation proceeded smoothly in all cases, and the desired compounds were isolated and characterized. In the trifluoromethylation of 3-iodo-4-methoxyquinoline, we observed a concomitant O-N methyl migration, resulting in the trifluoromethylated quinolone as a product. Overall, the described procedure should facilitate the broader use of copper-catalyzed trifluoromethylation in medicinal chemistry.


Asunto(s)
Alquenos/química , Cobre/química , Hidrocarburos Fluorados/química , Catálisis , Metilación , Estructura Molecular
12.
Org Biomol Chem ; 17(36): 8343-8347, 2019 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-31268086

RESUMEN

Structurally different bis(imino)copper(i) complexes were prepared in a highly modular manner and utilized as copper-based photocatalysts in the ATRA reactions of styrenes and alkyl halides. The new photocatalysts showed good catalytic activity and ensured efficient chemical transformations.

13.
BMC Pediatr ; 19(1): 368, 2019 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-31640618

RESUMEN

BACKGROUND: Aspiration of grass inflorescences is an extremely rare phenomenon with potential diagnostic difficulties. Due to its special shape, each coughing and respiratory action helps its migration towards the periphery of lung, resulting late-onset, life-threatening complications. The diagnosis has some difficulties for the reason that soon after the aspiration initial symptoms, such as coughing, wheezing or vomiting disappear and bronchoscopy is mostly negative. At least serious complications such as tension pneumothorax, bronchopleurocutaneous fistula or even spontaneous percutan elimination may develope. CASE PRESENTATION: We present two cases of pleuropneumonia resulting from aspiration of the head of barley grass. Soon after the accidents initial symptoms diminished, inflammatory markers improved and bronchoscopy was unable to confirm the presence of awn. Despite of conservative treatment (antibiotics, physiotherapy, bronchodilators, expectorants, and inhalation) localized pulmonary inflammation developed after 1 and 9 months showed up on chest computed tomography. After ineffective conservative treatment, surgical resections became inevitable in order to remove chronically inflamed parts (lobectomy, segmentectomy) and foreign bodies. Both patients recovered and were discharged home after successful interventions. CONCLUSIONS: Due to its peculiar shape and behaviour, awn inhalation is a special and atypical form of aspiration, thus great care and awareness is needed in its treatment. Negative bronchoscopic result does not exclude the presence of bronchial grass head. Symptomless child with negative bronchoscopy and improved inflammatory markers should be followed up thoroughly to recognize late complications in time. Regular diagnostic steps (chest ultrasound/X-ray) should be performed to localize potential chronic lung inflammation. Chest computed tomography is a valuable diagnostic tool for identifying and localising the foreign body. In cases with localized inflammation and peripheric localisation, segmentectomy can be a successful and safe alternative of lobectomy.


Asunto(s)
Bronquios , Fístula Bronquial/etiología , Fístula Bronquial/cirugía , Bronquiectasia/etiología , Bronquiectasia/cirugía , Cuerpos Extraños/etiología , Cuerpos Extraños/cirugía , Hordeum/efectos adversos , Enfermedades Pleurales/etiología , Enfermedades Pleurales/cirugía , Fístula del Sistema Respiratorio/etiología , Fístula del Sistema Respiratorio/cirugía , Niño , Preescolar , Cuerpos Extraños/complicaciones , Humanos , Masculino , Aspiración Respiratoria
14.
J Org Chem ; 83(15): 8281-8291, 2018 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-29842774

RESUMEN

For the synthesis of unsymmetrical acetylenes, a Sonogashira coupling-deprotection-Sonogashira coupling reaction sequence is often used. Removal of protecting groups requires harsh conditions or an excess of difficult to handle and expensive reagents. Herein, we disclose a novel catalytic method for the selective deprotection of trimethylsilylacetylenes in Sonogashira reaction. The reagent hexafluorosilicic acid, an inexpensive nontoxic compound, was used to promote the selective desilylation. This method enables the efficient synthesis of unsymmetric acetylenes with other silylated functional groups present. Further possibilities of the method were explored by synthesis of heterocycles.

15.
Org Biomol Chem ; 16(26): 4895-4899, 2018 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-29938279

RESUMEN

A novel disconnection based on cross-coupling chemistry was designed to access pharmaceutically relevant aryl-aminoethyl ethers. The developed palladium-catalyzed functionalization of aryl- and heteroaryl chlorides with a sodium tetrakis-(2-chloroethoxy) borate salt is orthogonal to the simple nucleophilic replacement of the chloro function of the ethylene linker. The transformation enables efficient 2-chloroethoxylation in the absence of an additional external base. Subsequent amine substitution of the alkyl halide affords 2-aminoethoxy arenes. The applicability of this method was demonstrated through the synthesis of various aryl- and heteroaryl-alkyl ethers, including the intermediates of marketed drug molecules.

16.
Angew Chem Int Ed Engl ; 57(22): 6643-6647, 2018 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-29660841

RESUMEN

The synthesis of fluorinated compounds and their use as pharmaceutical ingredients or synthetic building blocks have been in the focus of chemical and medicinal research. However, the efficient synthesis of trifluoromethylated nitrogen heterocycles is sometimes challenging. Herein, we disclose a simple aziridination process that relies on the use of amines and novel alkenyl iodonium reagents for the synthesis of strained, trifluoromethylated heterocycles. With the utilization of a newly designed and bench-stable but highly reactive hypervalent alkenyl iodonium species, these three-membered-ring heterocyclic compounds can be efficiently constructed from simple amines under mild conditions in the absence of transition-metal catalysts. The special reactivity of the new trifluoropropenyl synthon towards nucleophilic centers could be exploited in more general cyclization and alkenylation reactions in the future.

17.
Beilstein J Org Chem ; 14: 1743-1749, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30112079

RESUMEN

We present a computational mechanistic study on the copper(III)-catalysed carboarylation-ring closure reactions leading to the formation of functionalised heterocycles. We have performed DFT calculations along selected routes and compared their free energy profiles. The calculations considered two viable options for the underlying mechanism which differ in the order of the oxazoline ring formation and the aryl transfer steps. In our model transformation, it was found that the reaction generally features the aryl transfer-ring closing sequence and this sequence shows very limited sensitivity to the variation of the substituent of the reactants. On the basis of the mechanism the origin of the stereoselectivity is ascribed to the interaction of the Cu ion with the oxazoline oxygen driving the ring-closure step selectively.

18.
Chemistry ; 23(62): 15628-15632, 2017 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-28885747

RESUMEN

A simple and convenient method was developed for the introduction of a 2,2,2-trifluoroethoxy group to various aromatic and heteroaromatic systems. The novel process utilizes aromatic chlorides as substrates, and tetrakis(2,2,2-trifluoroethoxy) borate salt as an inexpensive and readily available fluoroalkoxy source in a palladium-catalyzed cross-coupling reaction. The power of the developed methodology was demonstrated in the synthesis of a fluorous derivative of Sildenafil.


Asunto(s)
Boratos/química , Flúor/química , Paladio/química , Citrato de Sildenafil/análogos & derivados , Animales , Barrera Hematoencefálica/metabolismo , Catálisis , Cloruros/química , Semivida , Humanos , Masculino , Ratas , Citrato de Sildenafil/síntesis química , Citrato de Sildenafil/farmacocinética
19.
Chem Rec ; 17(2): 184-199, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27501854

RESUMEN

This account collects the developments and transformations which avoid the utilization of harsh reaction conditions in the field of palladium catalyzed, ortho-directed C-H activation of aniline derivatives from the first attempts to up-to-date results, including the results of our research laboratory. The discussed functionalizations performed under mild conditions include acylation, olefination, arylation, alkylation, alkoxylation reactions. Beside the optimization studies and the synthetic applications mechanistic investigations are also presented.

20.
J Org Chem ; 82(22): 11752-11764, 2017 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-28853569

RESUMEN

A novel synthetic methodology was developed for the N-arylation of nitroenamine derivatives utilizing diaryliodonium triflates and copper(I) chloride as a catalyst. The procedure enables the easy aryl transfer from the hypervalent species under mild catalytic conditions with unusual heteroatom preference and high efficiency.

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