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A Pd(ii)-catalyzed direct functionalization reaction of the 4Csp2-H bond of antipyrine derivatives is reported. This metal-catalyzed reaction of antipyrines with maleimides provided an easy and efficient access to biologically important pyrazolonomaleimides. This catalytic system is also applicable for C-4 functionalization of the antipyrine ring with quinone derivatives.
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Correction for 'Ruthenium(II)-catalyzed decarbonylative and decarboxylative coupling of isatoic anhydrides with salicylaldehydes: access to aryl 2-aminobenzoates' by Bidisha R. Bora et al., Org. Biomol. Chem., 2021, 19, 2725-2730, DOI: 10.1039/d1ob00027f.
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A novel Ru(ii)-catalyzed decarbonylative annulation and direct C-H functionalization reaction of phthalic anhydrides with acrylates is reported. This reaction provides an efficient route for the synthesis of 3,7-disubstituted phthalides.
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A ruthenium(ii)-catalyzed coupling reaction of isatoic anhydrides and salicylaldehydes has been developed for the synthesis of 2-aminobenzoates. This reaction proceeds through metal-catalyzed decarbonylation and decarboxylation to afford good yields of aryl 2-aminobenzoates.
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In our interest in oxabicyclic compounds as potent antileishmanial agents, the present work deals with the chemical synthesis of a new oxabicyclic derivative, methyl 4-(7-hydroxy-4,4,8-trimethyl-3-oxabicyclo[3.3.1]nonan-2-yl)benzoate (PS-207). This oxabicyclic derivative showed a good antileishmanial effect on the parasite, on both the promastigote and the amastigote. The mode of parasitic death from PS-207 seemed to be apoptosis-like. Interestingly, the combination of PS-207 with a low dose of miltefosine showed a synergistic effect against the parasite.
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Antiprotozoarios/farmacología , Benzoatos/farmacología , Leishmania donovani/efectos de los fármacos , Leishmaniasis Visceral/tratamiento farmacológico , Fosforilcolina/análogos & derivados , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Humanos , Concentración 50 Inhibidora , Leishmaniasis Visceral/microbiología , Fosforilcolina/farmacología , Células U937RESUMEN
Bismuth trifluoromethanesulfonate can be efficiently used for the preparation of dihydropyrans from ß-allenols and aldehydes by oxonium-ene reaction in good yields. The reaction is highly regioselective. On the other hand, the same reaction with trimethylsilyl trifluoromethanesulfonate at -45 °C affords the hexahydropyrano[4,3- b]pyran skeleton in moderate yields.
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A novel and facile regioselective synthesis of furan-3-carboxamides by a silver(i)/base-promoted reaction of propargyl alcohol with 3-oxo amides has been demonstrated. This one-pot protocol provides a rapid synthetic approach to diverse trisubstituted furan-3-carboxamides via cascade nucleophilic addition, intramolecular cyclization, elimination, and isomerization reactions. Employing a substituted propargyl alcohol, (Z)-enaminones have been obtained with high stereoselectivities by a Ag2CO3-promoted reaction starting from 3-oxo amides via C-N bond cleavage.
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OBJECTIVE: Drug-resistant tuberculosis (TB) threatens global TB control because it is difficult to diagnose and treat. Community-based programmatic management of drug-resistant TB (cPMDT) has made therapy easier for patients, but data on these models are scarce. Bangladesh initiated cPMDT in 2012, and in 2013, we sought to evaluate programme performance. METHODS: In this retrospective review, we abstracted demographic, clinical, microbiologic and treatment outcome data for all patients enrolled in the cPMDT programme over 6 months in three districts of Bangladesh. We interviewed a convenience sample of patients about their experience in the programme. RESULTS: Chart review was performed on 77 patients. Sputum smears and cultures were performed, on average, once every 1.35 and 1.36 months, respectively. Among 74 initially culture-positive patients, 70 (95%) converted their cultures and 69 (93%) patients converted the cultures before the sixth month. Fifty-two (68%) patients had evidence of screening for adverse events. We found written documentation of musculoskeletal complaints for 16 (21%) patients, gastrointestinal adverse events for 16 (21%), hearing loss for eight (10%) and psychiatric events for four (5%) patients; conversely, on interview of 60 patients, 55 (92%) reported musculoskeletal complaints, 54 (90%) reported nausea, 36 (60%) reported hearing loss, and 36 (60%) reported psychiatric disorders. CONCLUSIONS: The cPMDT programme in Bangladesh appears to be programmatically feasible and clinically effective; however, inadequate monitoring of adverse events raises some concern. As the programme is brought to scale nationwide, renewed efforts at monitoring adverse events should be prioritised.
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Hexahydrobenzo[de]isochromanes and hexahydropyrano[3,4,5-ij]isoquinolines can be efficiently synthesized via Friedel Crafts and oxa Pictet-Spengler reaction of acrylyl enol ethers mediated by triflic acid in good yields. The reaction is highly stereoselective. Two of the hexahydrobenzo[de]isochromanes are found to have moderate antileishmanial activity.
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Acetatos/farmacología , Antiprotozoarios/síntesis química , Antiprotozoarios/farmacología , Benzopiranos/farmacología , Leishmania donovani/efectos de los fármacos , Acetatos/síntesis química , Acetatos/química , Antiprotozoarios/química , Benzopiranos/síntesis química , Benzopiranos/química , Relación Dosis-Respuesta a Droga , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Intramolecular hydroalkoxylation/hydrothioalkoxylation of nitrogen-tethered alkenes and alcohols/thiols mediated by boron trifluoride etherate leads to five-membered thiazolidine, six-membered 1,4-oxazines (morpholines) and tetrahydro-2H-1,4-thiazines (thiomorpholines), and seven-membered 1,4-oxazepanes in good yields.
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Alcoholes/química , Compuestos Heterocíclicos/síntesis química , Cristalografía por Rayos X , Compuestos Heterocíclicos/química , Modelos Moleculares , Conformación MolecularRESUMEN
Systems for disease vector control should be effective, efficient, and flexible to be able to tackle contemporary challenges and threats in the control and elimination of vector-borne diseases. As a priority activity towards the strengthening of vector control systems, it has been advocated that countries conduct a vector-control needs assessment. A review was carried out of the perceived needs for disease vector control programs among eleven countries and subnational states in South Asia and the Middle East. In each country or state, independent teams conducted vector control needs assessment with engagement of stakeholders. Important weaknesses were described for malaria, dengue and leishmaniases regarding vector surveillance, insecticide susceptibility testing, monitoring and evaluation of operations, entomological capacity and laboratory infrastructure. In addition, community mobilization and intersectoral collaboration showed important gaps. Countries and states expressed concern about insecticide resistance that could reduce the continued effectiveness of interventions, which demands improved monitoring. Moreover, attainment of disease elimination necessitates enhanced vector surveillance. Vector control needs assessment provided a useful planning tool for systematic strengthening of vector control systems. A limitation in conducting the vector control needs assessment was that it is time- and resource-intensive. To increase the feasibility and utility of national assessments, an abridged version of the guidance should focus on operationally relevant topics of the assessment. Similar reviews are needed in other regions with different contextual conditions.
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Enfermedades Transmitidas por Vectores , Animales , Humanos , Sur de Asia/epidemiología , Dengue/prevención & control , Dengue/epidemiología , Dengue/transmisión , Vectores de Enfermedades , Insecticidas , Malaria/prevención & control , Malaria/epidemiología , Medio Oriente/epidemiología , Evaluación de Necesidades , Enfermedades Transmitidas por Vectores/prevención & control , Enfermedades Transmitidas por Vectores/transmisiónRESUMEN
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) can be efficiently used for Prins cyclization of acrylyl enol ethers to 5,6-dihydro-2H-pyran-2-acetates stereo- and regioselectively in good yields. The methodology was used for the total synthesis of natural product (+)-civet.
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Productos Biológicos/síntesis química , Éteres/química , Piranos/síntesis química , Animales , Productos Biológicos/química , Ciclización , Estructura Molecular , Piranos/química , Estereoisomerismo , ViverridaeRESUMEN
Substituted dihydropyrans can be efficiently synthesized in good yields with excellent diastereoselectivity from the reaction of aldehydes or epoxides and ethyl 3-alkyl-3-hydroxy-5-methylhex-5-enoate via an oxonium-ene cyclization reaction catalyzed by trimethylsilyl trifluoromethanesulfonate (TMSOTf) under mild conditions.
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Piranos/química , Piranos/síntesis química , Aldehídos/química , Catálisis , Ciclización , Compuestos Epoxi/química , Ésteres/química , Mesilatos/química , Estructura Molecular , Estereoisomerismo , Compuestos de Trimetilsililo/químicaRESUMEN
The Sc(OTf)3/BF3·OEt2-catalyzed annulation of 3-formylchromones with functionalized alkenes for the direct construction of 2-hydroxybenzophenones is described. Sc(OTf)3/BF3·OEt2 acts as a synergistic catalyst, providing rapid synthetic access to diversely and highly functionalized 2-hydroxybenzophenones. This reaction has excellent regio- and chemoselectivities and is suitable for late-stage functionalization. The reaction proceeds via [3 + 3] and [4 + 2] cycloaddition processes, through carbonyl-ene, Diels-Alder, or aldol-type reactions. Furthermore, this protocol tolerates the various functional groups present in natural terpenes and steroids.
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Alquenos , Benzofenonas , Catálisis , Cromonas , EstereoisomerismoRESUMEN
The Pd(ii)-catalyzed activation of Csp2-H bond and double alkyne annulation which proceeds via allylic isomerization is reported for the first time. This reaction of antipyrines with alkynes provides an efficient synthetic route for the biologically important spiro-cyclopentadiene pyrazolones. In the presence of Lawesson's reagent, this Pd(ii)-catalyzed annulation reaction affords another spiro-cyclopentadiene pyrazolone which displays very good fluorescence properties.
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BACKGROUND: About 35% of the global burden of disease has roots in adolescence. Health in adolescence is an important determinant of health in adulthood. OBJECTIVES: This study aimed to generate risk scores for lifestyle behaviors among adolescents and to estimate the country-specific prevalence of these risk scores. The study also examined the relations of lifestyle risk scores with overweight or obesity among adolescents. METHODS: We used the most recent data available from 20 nationally representative Global School-based Student Health Surveys. Our analytical sample size was 51,597. The outcome of interest was overweight or obesity. We developed 4 lifestyle risk scores (dietary habits, physical activity, sedentary behavior, and tobacco use), which were used as the exposure variables in this study. Multilevel logistic regression models were used to estimate adjusted ORs with 95% CIs. RESULTS: In total, 18.2% of the participants were overweight or obese. Across countries, the percentage of adolescents with unhealthy dietary habits ranged from 76.7% (the Cook Islands) to 94.2% (Timor-Leste), physical inactivity ranged from 47.5% (Bangladesh) to 90.1% (the Philippines), and sedentary behavior ranged from 34.5% (Nepal) to 88.2% (Kuwait). Girls engaged in less physical activity than did boys. Increased odds of overweight or obesity were found among participants with high risk scores for physical inactivity (OR: 1.19; 95% CI: 1.11, 1.27) and for unhealthy sedentary behavior (OR: 1.25; 95% CI: 1.16, 1.35) compared with participants with low risk scores. Girls with high tobacco risk scores had higher odds (OR: 1.30; 95% CI: 1.02, 1.65) of overweight or obesity than did girls with low risk scores for tobacco use, whereas there were no significant differences in risk in boys. CONCLUSIONS: Unhealthy lifestyle behaviors were quite prevalent among adolescents, and higher lifestyle risk scores increased the risk of overweight or obesity.