Silylaryl triflates in the formation of arynes with application in the preparation of N,N-diarylamino acid derivatives

<p><strong><em></em></strong><em>Through this work we are developing our research involving the formation of arynes from 2-(trimethylsilyl)aryl triflates, under relatively mild reaction conditions. Thus, esters of amino acids are being subjected to the reaction with 2-(trimethylsilyl)aryl triflates, using cesium fluoride in acetonitrile at 80^oC for 24 h, resulting in the formation of N,N-diarylamino acid derivatives, important chiral intermediates in the construction of peptides and drugs.</em></p

ULTRASOUND-PROMOTED RAPID and EFFICIENT IODINATION of AROMATIC and HETEROAROMATIC COMPOUNDS in the PRESENCE of IODINE and HYDROGEN PEROXIDE in WATER

A rapid and efficient ultrasound-promoted protocol for iodination of aromatic and heteroaromatic compounds, using molecular iodine in the presence of aqueous hydrogen peroxide in water without any cosolvent, has produced versatile iodinated organic molecules with potential application in organic synthesis and medicine in short reaction times and good to excellent yields.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Fundacao Univ Fed Grande Dourados, Fac Ciencias Exatas & Tecnol, BR-79804970 Dourados, MS, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilWeb of Scienc

Immobilization of Amano lipase from Pseudomonas fluorescens on silk fibroin spheres: an alternative protocol for the enantioselective synthesis of halohydrins

The search for a new, efficient, cheaper and sustainable matrix for lipase immobilization is a growing area in biotechnology. Amano lipase from Pseudomonas fluorescens was immobilized on silk fibroin spheres and used in the enzymatic kinetic resolution of halohydrins, to obtain optically active epoxides (up to 99% ee), important precursors in the synthesis of derivative antifungal azoles. This paper reinforces the versatility of silk fibroin as a support for heterogeneous catalysts.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Sao Carlos, Inst Quim Sao Carlos, Ave Joao Dagnone, Ed Quim Ambiental, BR-13563120 Sao Carlos, BrazilUniv Fed Amapa, Grp Biocatalise & Biotransformacao Quim Organ, Rod Juscelino Kubitscheck,KM 02 S-N, BR-68903419 Macapa, AP, BrazilUniv Sao Paulo, Inst Quim Sao Carlos, Lab Bioquim & Biomat, Ave Trabalhador Sao Carlense 400, BR-13560970 Sao Carlos, SP, BrazilUniv Sao Paulo, Inst Quim, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Ave Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilInstituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Av. Prof. Artur Riedel, 275, 09972-270 Diadema, BrazilCNPq: 558062/2009-1CNPq: 558062/2009-1FAPESP: 2009/50688-3Web of Scienc

Efficient and eco-friendly synthesis of iodinated aromatic building blocks promoted by iodine and hydrogen peroxide in water: a mechanistic investigation by mass spectrometry

The reaction of aromatic and heteroaromatic compounds with molecular iodine in the presence of aqueous hydrogen peroxide using water without any co-solvent at 50 degrees C for 24 h produced versatile iodinated organic molecules with potential application in organic synthesis and medicine in very good yields. in addition, a mechanistic investigation for the iodination process was carried out by mass spectrometry. (C) 2012 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Universidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilFundacao Univ Fed Grande Dourados, Fac Ciencias Exatas & Tecnol, BR-79804970 Dourados, MS, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilWeb of Scienc

Ene-reductases: Contribution from Brazilian fungi in organic synthesis

Brazil’s territory encloses six terrestrial biomes (Amazon, Pantanal, Savannah, Atlantic Rainforest, and Caatinga-Savannah cactus) and a marine biome following the long coastline, yielding a wealth of native microbial species. Fungi found in different parts of Brazil are being studied for their enzymatic potential in biotransformation in organic synthesis processes. This review summarizes various studies on the bioreduction of activated C = C double bonds catalyzed by ene-reductases using fungi (filamentous and yeast) from the Brazilian environmental

Fridel-Crafts alkylation of iodine catalyed by ultrasound assisted

Triarymethanes (TRAMs) are used as antitubercular agents, antitumor or antiviral.1 Was weighed 2 mmol of (1a), 1 mmol of (2a), 10 mol% of I2 in 5 mL of CH2Cl2, the reaction was brought to ultrasound bath (SONIC MODEL LS-4, 7D) of 44 kH and 150 W (Scheme 1).The product was purified on silica gel-60, eluting mixture 8:2 of (Hexano:Ethyl acetate). Under these conditions 65% of the product (3a) was obtained. The compound was characterized by third m.p. 161ºC (161-162ºC).1 The Fridel-Crafts alkylation catalyzed by I2 bath ultrasound occurs at short reaction time requiring less energy expenditure compared to the method of agitation. It is intended to increase the study of various aromatic compounds (1), different aldehydes (2) and vary the use of solvents

Anti-Melanogenic Potential of Natural and Synthetic Substances: Application in Zebrafish Model

Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme in the process of pigmentation through melanin is tyrosinase, which catalyzes the first and only limiting step in melanogenesis. Since the discovery of its methanogenic properties, tyrosinase has been the focus of research related to the anti-melanogenesis. In addition to developing more effective and commercially safe inhibitors, more studies are required to better understand the mechanisms involved in the skin depigmentation process. However, in vivo assays are necessary to develop and validate new drugs or molecules for this purpose, and to accomplish this, zebrafish has been identified as a model organism for in vivo application. In addition, such model would allow tracking and studying the depigmenting activity of many bioactive compounds, important to genetics, medicinal chemistry and even the cosmetic industry. Studies have shown the similarity between human and zebrafish genomes, encouraging their use as a model to understand the mechanism of action of a tested compound. Interestingly, zebrafish skin shares many similarities with human skin, suggesting that this model organism is suitable for studying melanogenesis inhibitors. Accordingly, several bioactive compounds reported herein for this model are compared in terms of their molecular structure and possible mode of action in zebrafish embryos. In particular, this article described the main metabolites of Trichoderma fungi, in addition to substances from natural and synthetic sources

Green Extraction of Annatto Seed Oily Extract and Its Use as a Pharmaceutical Material for the Production of Lipid Nanoparticles

This work developd nanomaterials formulated from annatto seed oily extract (ASE), myristic acid (tetradecanoic acid), and their fatty acid esters. The annatto seed oily extract was obtained using only soybean oil (ASE + SO) and Brazil nut oil (ASE + BNO). The UV/VIS analysis of the oily extracts showed three characteristic peaks of the bixin molecule at 430, 456 and 486 nm. The lipid nanoparticles obtained using myristic acid and ASE + BNO or only BNO showed better results than the oil soybean extract, i.e., the particle size was &lt;200 nm, PDI value was in the range of 0.2&ndash;0.3, and had no visual physical instability as they kept stable for 28 days at 4 &deg;C. Lipid nanoemulsions were also produced with esters of myristic acid and ASE + BNO. These fatty acid esters significantly influenced the particle size of nanoemulsions. For instance, methyl tetradecanoate led to the smallest particle size nanoemulsions (124 nm), homogeneous size distribution, and high physical stability under 4 and 32 &deg;C for 28 days. This work demonstrates that the chemical composition of vegetable oils and myristic acid esters, the storage temperature, the chain length of fatty acid esters (FAE), and their use as co-lipids improve the physical stability of lipid nanoemulsions and nanoparticles from annatto seed oily extract