Síntese de tetra-hidropiridinas por meio de reações multicomponentes

Multicomponent Reactions are defined as reactions between three or more reagents in a single reaction step in the same reaction vial, forming a product that includes the majority of atoms and structural characteristics of the reagents. Thus these reactions save time and energy. One of the ways to improve the yield and reaction time of a multicomponent reaction is to use different catalysts, an example of catalyst that shows great potential and has been studied in recent years is the molecular iodine is known to be a Lewis acid with high catalytic power. The functionalized piperidines, also known as tetrahydropyridines, are alkaloids that have pharmacological potential, this is due to the piperidine ring present in many natural product structures with muscarinic activity, nicotine, analgesic, antipsychotic, anti-proliferative, among others. In this paper we describe studies about on the application of molecular iodine (I2) in the multicomponent reaction between aniline derivatives, benzaldehyde and β-ketoester (methyl acetoacetate) for the synthesis of functionalized piperidines and the synthesis of a corresponding piperidone by acid hydrolysis. Data analysis allowed us to demonstrate the efficacy of molecular iodine in the synthesis of functionalized piperidines, obtaining results with yields 44-87% and short reaction time of 8 to 24 hours, and the efficacy of acid hydrolysis of enamine in the structure of the tetrahydropyridine derivative in a yield of 81%

Obtenção e caracterização de nanoestruturas puras e dopadas a base de 'TI''O'IND.2' para a aplicação em fotocatálise

Pós-graduação em Química - IQ

Tratamento anaeróbio-aeróbio de águas residuárias do processamento de cafeeiro em reatores biológicos

Pós-graduação em Microbiologia Agropecuária - FCAV

The "chemical oxygen demand/total volatile acids" ratio as an anaerobic treatability indicator for landfill leachates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho perceptivo-auditivo de crianças na identificação de contrastes fonológicos entre as oclusivas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise de parâmetros neuromusculares e cinemáticos dos chutes Bandal Chagui e Dolhô Chagui do Taekwondo

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Dimetilsulfóxidos como ligantes ancilares em complexos de rutênio: catalisadores duais para a combinação da ROMP de norborneno e ATRP de metacrilato de metila

Pós-graduação em Química - IBILCE

Estudos sobre o uso de NbCl5 como ácido de Lewis em reações de Povarov

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The chemical oxygen demand / total volatile acids ratio as an anaerobic treatability indicator for landfill leachates

In some operational circumstances a fast evaluation of landfill leachate anaerobic treatability is necessary, and neither Biochemical Methane Potential nor BOD/COD ratio are fast enough. Looking for a fast indicator, this work evaluated the anaerobic treatability of landfill leachate from São Carlos-SP (Brazil) in a pilot scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR). The experiment was conducted at ambient temperature in the landfill area. After the acclimation, at a second stage of operation, the AnSBBR presented efficiency above 70%, in terms of COD removal, utilizing landfill leachate without water dilution, with an inlet COD of about 11,000 mg.L-1, a TVA/COD ratio of approximately 0.6 and reaction time equal to 7 days. To evaluate the landfill leachate biodegradability variation over time, temporal profiles of concentration were performed in the AnSBBR. The landfill leachate anaerobic biodegradability was verified to have a direct and strong relationship to the TVA/COD ratio. For a TVA/CODTotal ratio lower than 0.20, the biodegradability was considered low, for ratios between 0.20 and 0.40 it was considered medium, and above 0.40 it was considered high.

Task complexity reveals expertise of table tennis players

AIM: The purpose of this study was to examine the effect of intensive practice in table-­tennis on perceptual, decision-­making and motor-­systems. Groups of elite (HL=11), intermediate (LL=6) and control (CC=11) performed tasks of different levels. METHODS: All subjects underwent to reaction-­time-­test and response-­time-­test consisting of a pointing task to targets placed at distinct distances (15 and 25-­cm) on the right and left sides. The ball speed test in forehand and backhand condition just for HL and LL group. RESULTS: In CC group reaction time was higher compared to HL (P< 0.05) group. In the response-­time-­test, there was a significant main effect of distance (P< 0.0001) and the tennis-­table expertise (P= 0.011). In the ball speed test the HL were constantly faster compared to the LL in both forehand stroke (P< 0.0001) and backhand stroke (P< 0.0001). Overall, the forehand stroke was significantly faster than the backhand stroke. CONCLUSION: We can conclude that table-­tennis-­players have shorter response-­times than non-­athletes and the tasks of reaction-­time and response-­time are incapable to distinguish the performance of well-­trained table tennis players of the intermediate player, but the ball speed test seems be able to do it.

Identificação de contrastes vocálicos do Português Brasileiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Enhanced Polymer Grafting from Multiwalled Carbon Nanotubes through Living Anionic Surface-Initiated Polymerization

Anionic surface-initiated polymerization of ethylene oxide and styrene has been performed using multiwalled carbon nanotubes (MWNTs) functionalized with anionic initiators. The surface of MWNTs was modified via covalent attachment of precursor anions such as 4-hydroxyethyl benzocyclobutene (BCBEO) and 1-benzocyclobutene-1′-phenylethylene (BCB-PE) through Diels-Alder cycloaddition at 235 °C. Surface-functionalized MWNTs-g-(BCB-EO) n and MWNTs-g-(BCB-PE) n with 23 and 54 wt % precursor initiators, respectively, were used for the polymerizations. Alkoxide anion on the surface of MWNTs-g-(BCB-EO) n was generated through reaction with potassium triphenylmethane for the polymerization of ethylene oxide in tetrahydrofuran and phenyl substituted alkyllithium was generated from the surface of MWNTs-g-(BCB-PE) n using sec-butyllithium for the polymerization of styrene in benzene. In both cases, the initiation was found to be very slow because of the heterogeneous reaction medium. However, the MWNTs gradually dispersed in the reaction medium during the polymerization. A pale green color was noticed in the case of ethylene oxide polymerization and the color of initiator as well as the propagating anions was not discernible visually in styrene polymerization. Polymer grafted nanocomposites, MWNTs-g-(BCB-PEO) n and MWNTs-g-(BCB-PS) n containing a very high percentage of hairy polymer with a small fraction of MWNTs (<1 wt %) were obtained. The conversion of ethylene oxide and the weight percent of PEO on the surface of the MWNTs increased with increasing reaction time indicating a controlled polymerization. The polymer-grafted MWNTs were characterized using FTIR, 1H NMR, Raman spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and transmission electron microscopy (TEM). Size exclusion chromatography of the polymer grafted MWNTs revealed broad molecular weight distributions (1.3 < Mw/Mn < 1.8) indicating the presence of different sizes of polymer nanocomposites. The TEM images showed the presence of thick layers of polymer up to 30 nm around the MWNTs. The living nature of the growing polystyryllithium was used to produce diblock copolymer grafts using sequential polymerization of isoprene on the surface of MWNTs.

I. Development of the In Situ Reductive Ozonolysis of Alkenes with Tertiary Amine N-Oxides. II. Progress toward the Asymmetric Synthesis of Peroxyplakoric Acid A3.

Ozone, first discovered in the mid 1800’s, is a triatomic allotrope of oxygen that is a powerful oxidant. For over a century, research has been conducted into the synthetic application and mechanism of reactions of ozone with organic compounds. One of the major areas of interest has been the ozonolysis of alkenes. The production of carbonyl compounds is the most common synthetic application of ozonolysis. The generally accepted mechanism developed by Rudolf Criegee for this reaction involves the 1,3-electrocyclic addition of ozone to the π bond of the alkene to form a 1,2,3-trioxolane or primary ozonide. The primary ozonide is unstable at temperatures above -100 °C and undergoes cycloreversion to produce the carbonyl oxide and carbonyl intermediates. These intermediates then recombine in another 1,3-electrocyclic addition step to form the 1,2,4-trioxolane or final ozonide. While the final ozonide is often isolable, most synthetic applications of ozonolysis require a subsequent reductive or oxidative step to form the desired carbonyl compound. During investigations into the nucleophilic trapping of the reactive carbonyl oxide, it was discovered that when amines were used as additives, an increased amount of reaction time was required in order to consume all of the starting material. Surprisingly, significant amounts of aldehydes and a suppression of ozonide formation also occurred which led to the discovery that amine N-oxides formed by the ozonation of the amine additives in the reaction were intercepting the carbonyl oxide. From the observed production of aldehydes, our proposed mechanism for the in situ reductive ozonolysis reaction with amine N-oxides involves the nucleophilic trapping of the carbonyl oxide intermediate to produce a zwitterionic adduct that fragments into 1O2, amine and the carbonyl thereby avoiding the formation of peroxidic intermediates. With the successful total syntheses of peroxyacarnoates A and D by Dr. Chunping Xu, the asymmetric total synthesis of peroxyplakorate A3 was investigated. The peroxyplakoric acids are cyclic peroxide natural products isolated from the Plakortis species of marine sponge that have been found to exhibit activity against malaria, cancer and fungi. Even though the peroxyplakorates differ from the peroxyacarnoates in the polyunsaturated tail and the head group, the lessons learned from the syntheses of the peroxyacarnoates have proven to be valuable in the asymmetric synthesis of peroxyplakorate A3. The challenges for the asymmetric synthesis of peroxyplakorate A3 include the stereospecific formation of the 3-methoxy-1,2-dioxane core with a propionate head group and the introduction of oxidation sensitive dienyl tail in the presence of a reduction sensitive 1,2-dioxane core. It was found that the stereochemistry of two of the chiral centers could be controlled by an anti-aldol reaction of a chiral propionate followed by the stereospecific intramolecular cyclization of a hydroperoxyacetal. The regioselective ozonolysis of a 1,2-disubstituted alkene in the presence of a terminal alkyne forms the required hydroperoxyacetal as a mixture of diastereomers. Finally, the dienyl tail is introduced by a hydrometallation/iodination of the alkyne to produce a vinyl iodide followed by a palladium catalyzed coupling reaction. While the coupling reaction was unsuccessful in these attempts, it is still believed that the intramolecular cyclization to introduce the 1,2-dioxane core could prove to be a general solution to many other cyclic peroxides natural products.

Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration

A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2.4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe2+ ([Fe2+](0)) from 1.0 up to 2.5 mM, the rate in mmol of H2O2 fed into the system (F-H2O2,F-in) from 3.67 up to 7.33 mmol of H2O2/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes. (C) 2012 Elsevier Ltd. All rights reserved.

Cognitive function in patients with chronic pain treated with opioids: characteristics and associated factors

Background The paucity of studies regarding cognitive function in patients with chronic pain, and growing evidence regarding the cognitive effects of pain and opioids on cognitive function prompted us to assess cognition via neuropsychological measurement in patients with chronic non-cancer pain treated with opioids. Methods In this cross-sectional study, 49 patients were assessed by Continuous Reaction Time, Finger Tapping, Digit Span, Trail Making Test-B and Mini-mental State Examination tests. Linear regressions were applied. Results Patients scored poorly in the Trail Making Test-B (mean?=?107.6?s, SD?=?61.0, cut-off?=?91?s); and adequately on all other tests. Several associations among independent variables and cognitive tests were observed. In the multiple regression analyses, the variables associated with statistically significant poor cognitive performance were female sex, higher age, lower annual income, lower schooling, anxiety, depression, tiredness, lower opioid dose, and more than 5?h of sleep the night before assessment (P?<?0.05). Conclusions Patients with chronic pain may have cognitive dysfunction related to some reversible factors, which can be optimized by therapeutic interventions.