Irlon M. Ferreira

Biocatalysis and biotransformation in Brazil: An overview.

This review presents the recent research in biocatalysis and biotransformation in Brazil. Several substrates were biotransformed by fungi, bacteria and plants. Biocatalytic deracemization of secondary alcohols, oxidation of sulfides, sp(3) CH hydroxylation and epoxidation of alkenes were described. Chemo-enzymatic resolution of racemic alcohols and amines were carried out with lipases using several substrates containing heteroatoms such as silicon, boron, selenium and tellurium. Biotransformation of nitriles by marine fungi, hydrolysis of epoxides by microorganisms of Brazilian origin and biooxidation of natural products were described. Enzymatic reactions under microwave irradiation, continuous flow, and enzymatic assays using fluorescent probes were reported.

Fast Microwave-Assisted Resolution of (±)-Cyanohydrins Promoted by Lipase from Candida antarctica

Enzymatic kinetic resolution (EKR) of (±)-cyanohydrins was performed by using immobilized lipase from Candida antarctica (CALB) under conventional ordinary conditions (orbital shaking) and under microwave radiation (MW). The use of microwave radiation contributed very expressively on the reduction of the reaction time from 24 to 2 h. Most importantly, high selectivity (up to 92% eep) as well as conversion was achieved under MW radiation (50-56%).

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.

UM PROTOCOLO SIMPLES E EFICIENTE PARA A REAÇÃO DE KNOEVENAGEL DE BENZILIDENEMALONONITRILES E AVALIAÇÃO DA ATIVIDADE LARVICIDA EM AEDES AEGYPTI

Mosquitoes of the genus Aedes are responsible for dengue, yellow fever, chikungunya and Zika. Although important advances have emerged in the development of alternative methods for mosquito control, chemical insecticides remain a vital part of integrated control programs. In this paper were synthetized benzylidenemalononitrile derivatives in good yields (71-99%) using only water and glycerol at room temperature. A study of the larvicidal activity between benzylidenemalononitriles showed that the compound 2e (R= 4-Cl) possesses excellent larvicidal activity (LC50 and LC90 of 9.42 and 15.02, respectively at 24 h). A study of molecular docking was applied to identify the type of interaction of compound 2e with binding sites at the enzyme acetylcholinesterase. The profile of the interaction showed a score 48.9795 with five bonds at three different amino acids.Mosquitoes in the genus Aedes are responsible for the four important human disease viruses, such as, dengue, yellow fever, chikungunya and Zika. Although important advances have emerged in the development of alternative measures for mosquito control, chemical insecticides still remain a vital part of integrated control programs. In this sense, a set of benzylidenemalononitriles were synthetized in very good yields (99-71%), using only water and glycerol at temperature room. A comparative study of the larvicidal activity between benzylidenemalononitriles showed that the 2g (R= 4-Cl) compounds possess much better larvicidal activity (LC50 and LC90 of 9.42 and 15.02, respectively at 24h). Study of molecular docking was applied to identify the mode iteration of compound 2g with binding site at the enzyme acetylcholinesterase, the profile of interaction showed a score 48.9795, with five bonds in three different amino acids.

Ultrasound-promoted iodination of aromatic compounds in the presence of iodine and hydrogen peroxide in water.

th Brazilian Meeting on Organic Synthesis – 14 th BMOS – September 01-05, 2011-Brasilia, Brazil Ultrasound-promoted iodination of aromatic compounds in the presence of iodine and hydrogen peroxide in water. Irlon M. Ferreira, Rafael D. C. Gallo, Gleison A. Casagrande, Lucas Pizzuti* and Cristiano Raminelli* Faculdade de Ciencias Exatas e Tecnologia, Universidade Federal da Grande Dourados, Dourados, MS, Brazil *e-mail addresses: lucaspizzuti@ufgd.edu.br or raminelli@ufgd.edu.br

Iodination of aromatic and heteroaromatic compounds in the presence of iodine and hydrogen peroxide in water: A balance between atom economy and high yields.

INTRODUCTION Recently we published a work involving the efficient and selective diiodination of phenols using I2 and H2O2 30% in water. 1 Afterwards, we decided to subject aromatic and heteroaromatic compounds to the same reaction conditions, performing a balance between the amounts of the reagents and the yields obtained, aiming to the formation of interesting iodinated molecules in high yields. RESULTS AND DISCUSSION We treated phenol (1a) with 1.5 equiv. of I2 and 3 equiv. of H2O2 30% in water at 50 o C for 24 h and obtained 2,4,6-triiodophenol (2a) in a moderate yield of 65% (Table 1, entry 1). In the attempt of increasing this yield, we used 2 equiv. of I2 and 4 equiv. of H2O2 30% producing the triiodinated phenol 2a in a yield of 83% (entry 2). The aromatic compound 1b and the heteroaromatic compound 1c were subjected to the reaction with 2 equiv. of I2 and 4 equiv. of H2O2 30% resulting in the triiodinated products 2b and 2c, respectively, in good yields (entries 3 and 4). The balance between amounts of the reagents and yields obtained was extended for reactions of diiodination (entries 6 to 9) and for reactions of monoiodination (entries 10 to 15). In general, diiodinated and monoiodinated aromatic and heteroaromatic compounds were produced in considerable yields. CONCLUSION A balance between amounts of the reagents and the yields obtained was carried out for the reaction of iodination of aromatic organic compounds using I2 and H2O2 30% in water at 50 o C and interesting iodinated molecules were produced in good yields. ACKNOWLEDGEMENTS We thank CNPq and FUNDECT for support. REFERENCES

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

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 o C for 24 h, resulting in the formation of N,N-diarylamino acid derivatives, important chiral intermediates in the construction of peptides and drugs.