A5018277960- Organoselenium and organotellurium chemistry
- Sulfur-Based Synthesis Techniques
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Click Chemistry and Applications
- Chemical Synthesis and Reactions
- Chemical Synthesis and Analysis
- Organic Chemistry Cycloaddition Reactions
- Catalytic Alkyne Reactions
- Enzyme Catalysis and Immobilization
- Catalytic C–H Functionalization Methods
- Synthesis and Biological Evaluation
- Essential Oils and Antimicrobial Activity
- Catalytic Cross-Coupling Reactions
- Organometallic Compounds Synthesis and Characterization
- Insect and Pesticide Research
- Chemical synthesis and alkaloids
- Thermochemical Biomass Conversion Processes
- Phytochemicals and Antioxidant Activities
- Catalysis and Hydrodesulfurization Studies
- Asymmetric Hydrogenation and Catalysis
- Bee Products Chemical Analysis
- Synthesis and Reactivity of Sulfur-Containing Compounds
- Organic and Inorganic Chemical Reactions
- Nanomaterials for catalytic reactions
Universidade de Caxias do Sul
2014-2024
Natura (Brazil)
2018-2024
Biotechnology Institute
2023
Universidade Federal de Pelotas
2016
Philadelphia University
2013
University of Pennsylvania
2013
Universidade de São Paulo
2009-2011
BIO5 Institute
2008
Universidade Federal de Santa Maria
2008
Salvia officinalis (Lamiaceae) has been used in south of Brazil as a diary homemade, food condiment and tea-beverage for the treatment several disorders. The objective this study was to characterize chemical compounds hydroalcoholic (ExtHS) aqueous (ExtAS) extract from (L.) by gas chromatography-mass spectrometry (GC-MS) high-resolution electrospray ionization mass (ESI-QTOF MS/MS), evaluate vitro ability scavenge free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH•)...
The increased demand for pesticide-free foods has also the search healthier and environmentally friendly alternatives in agriculture. Essential oils are known to possess natural antifungal properties, becoming a reliable alternative commercial fungicides, especially postharvest decay control. However, essential volatile photodegradable, which reduces their long-term activities. This work presents development of lemongrass oil-containing poly(lactic acid) nanocapsules. They have shown vitro...
Most studies of Brazilian red propolis have explored the composition and biological properties its ethanolic extracts. In this work, we chemically extracted characterized essential oil (EOP) assessed adjuvant, antiparasitic cytotoxic activities. The chemical EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated different concentrations (ranging from 25 to 500 μg/mL)...
A simple and efficient method for the synthesis of 4‑organoselanyl-1H-pyrazoles has been developed, taking place under metal- halogen-free conditions. Electrophilic species selenium were easily generated in situ by reaction diorganyl diselenides with Oxone® ethanol as solvent an open-flask at 70 °C. These electrophilic employed selenylation/cyclization α,β-alkynyl hydrazones, giving title compounds moderate to excellent yields. The final obtained from diphenyl diselenide characterized 77Se...
We report here an alternative and tunable metal-free synthesis of benzo[<italic>b</italic>]chalcogenophenes <italic>via</italic> the electrophilic cyclization 2-functionalized chalcogenoalkynes promoted by Oxone®.
A method has been developed for the Pd-catalyzed synthesis of α-(hetero)aryl esters and amides through a Suzuki–Miyaura cross-coupling reaction. This avoids use strong base, does not necessitate inert or low temperature formation reagents, require large excess organometallic reagent. Utilization organotrifluoroborate salts as nucleophilic partners allows variety functional groups heterocyclic compounds to be tolerated.
Abstract We describe here for the first time synthesis of isochromenones fused to selenophenes. 5 H ‐Selenopheno[3,2‐ c ]isochromen‐5‐ones were obtained through a double intramolecular cyclization methyl 2‐(organyl‐1,3‐diynyl)benzoate promoted by electrophilic species selenium generated in situ reaction dialkyl diselenides with Oxone®, using ethanol as solvent. The reactions conducted satisfactorily under mild conditions, range 1,3‐diynes and substrates. A total sixteen unprecedent...
A new method was developed for the synthesis of 4-chalcogenyl-1H-isochromen-1-ones through 6-endo-dig electrophilic cyclization 2-alkynylaryl esters and diorganyl dichalcogenides under ultrasound irradiation. The reactions were performed mild conditions, using Oxone as a green oxidant to promote cleavage chalcogen–chalcogen bond in diselenides ditellurides generate species situ. total 25 compounds selectively obtained after 30–70 min, good excellent yields (74–95%). This procedure extended...
This paper describes an alternative method for the synthesis of 3‐organoselanylbenzo[ b ]furans through intramolecular cyclization 2‐alkynylphenols promoted by copper iodide and diorganyl diselenides. The reactions were carried out at room temperature in absence base under air (open flask). synthetic approach proved to be efficient with both diselenides bearing electron‐neutral, electron‐donating, electron‐withdrawing substituents. 2‐Phenyl‐3‐phenylselanylbenzo[ ]furan was used as a...
Easy access to mono- and bis-sulfenylindoles using the SeO<sub>2</sub>/I<sub>2</sub> system.
Red propolis is a natural resin mixture produced by honeybees and presents source of active compounds with variety biological activities. In this study, we describe the chemical characterization potential antitumor activity total extract Brazilian red its fractions. Fractions were obtained through column chromatography revealing 14 different in all samples, which determined distinguished other isobar molecules fragmentation pathways ESI-MS/MS positive mode. Some as cis-asarone or...
Herein, we describe a new strategy to prepare chalcogen-functionalized isoxazolines. The involves the reaction of β,γ-unsaturated oximes with electrophilic selenium and tellurium species, affording 19 selenium- tellurium-containing isoxazolines in good yields after 1 h at room temperature. method was efficiently extended synthesis 5 (bis)isoxazoline ditellurides. One prepared compounds, 3-phenyl-5-((phenylselanyl)methyl)-isoxazoline, demonstrated better anti-inflammatory antiedematogenic...
A simple method for the direct mono- and bis-organylselenylation of N-substituted pyrroles through a multicomponent reaction promoted by ultrasonic radiation was described. These sonochemical reactions were performed between different primary amines, 2,5-hexanedione dialkyl, diheteroaryl, or diaryl diselenides, using catalytic amounts copper iodide. Depending on amount iodide diorganyl diselenide used in reactions, products efficiently synthesized high yields.
A mild, stereoselective, and effective strategy has been developed for the synthesis of (E)-vinyl selenides tellurides by reaction potassium vinyltrifluoroborates with respective dichalcogenides using a copper salt as catalyst.
Abstract We describe herein an alternative method for the synthesis of 2‐aryl‐(3‐organochalcogenyl)thieno[2,3‐ b ]pyridines through electrophilic cyclization 3‐(arylethynyl)‐2‐(alkylthio)pyridines promoted by species organochalcogen compounds. These were generated in situ oxidative cleavage chalcogen‐chalcogen (Se, Te) bond diorganyl dichalcogenides using Oxone® ethanol as solvent open‐flask at 78 °C. The protocol allowed highly substituted thieno[2,3‐ starting from several and...
We describe here for the first time synthesis of 2-(chalcogenyl)-3H-benzo[f]chromenes and new 3-(phenylselanyl)-2H-chromenes by radical or electrophilic cyclization propargylic aryl ethers in presence diorganyl diselenides ditellurides using Oxone as a green oxidant acetonitrile solvent sealed tube at 100 °C. In this study, thirty-one chalcogenylchromenes with broad substrate scope were prepared moderate to excellent yields (50-98%), including compounds derived from natural products.
The first application of enzymes as catalysts to obtain optically pure boron compounds is described. kinetic resolution boron-containing chiral alcohols via enantioselective transesterification catalyzed by lipases was studied. Aromatic, allylic, and aliphatic secondary containing a boronate ester or boronic acid group were resolved lipase from Candida antartica (CALB), excellent E values (E > 200) high enantiomeric excesses (up >99%) both remaining substrates acetylated product obtained.