Browsing by Author "Saavedra-Olavarria, Jorge"
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- ItemAssessment of the Activity of Nitroisoxazole Derivatives against Trypanosoma cruzi(2024) Moncada-Basualto, Mauricio; Saavedra-Olavarria, Jorge; Rivero-Jerez, Paula S.; Rojas, Cristian; Maya, Juan D.; Liempi, Ana; Zuniga-Bustos, Matias; Olea-Azar, Claudio; Lapier, Michel; Perez, Edwin G.; Pozo-Martinez, JosueThe development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This study aims to investigate nitroisoxazole derivatives that produce oxidative stress while modifying the compounds' lipophilicity, affecting their ability to fight trypanosomes. The results indicate that these compounds are more effective against the epimastigote form of T. cruzi, with a 52 +/- 4% trypanocidal effect for compound 9. However, they are less effective against the trypomastigote form, with a 15 +/- 3% trypanocidal effect. Additionally, compound 11 interacts with a higher number of amino acid residues within the active site of the enzyme cruzipain. Furthermore, it was also found that the presence of a nitro group allows for the generation of free radicals; likewise, the large size of the compound enables increased interaction with aminoacidic residues in the active site of cruzipain, contributing to trypanocidal activity. This activity depends on the size and lipophilicity of the compounds. The study recommends exploring new compounds based on the nitroisoxazole skeleton, with larger substituents and lipophilicity to enhance their trypanocidal activity.
- ItemCopper-catalyzed intermolecular aminochlorination of alkenes(2018) Arteaga Arroyo, Gean Carlos; Saavedra-Olavarria, Jorge; Almendras Riesco, Sebastián Ignacio; Hermosilla-Ibanez, Patricio; Almodovar, Iriux; Pérez Hernández, Edwin Gregorio
- ItemEffect of the introduction of ethylenedioxythiophene and styrilnitroisooxazol groups on the properties and photovoltaic performances of tryphenylamine based π -conjugated push-pull molecules(2024) Arteaga, Gean C.; Louarn, Guy; Ramos-Hernandez, Andrea; Romero, Mario; Arzel, Ludovic; Bernede, Jean Christian; Saavedra-Olavarria, Jorge; Perez, Edwin G.; Maza, Julio R.; Romero, Jonathan; Cattin, LindaProperties of pi-conjugated push-pull molecules based on triphenylamine have been modified through the introduction of ethylenedioxythiophene and a styrilnitroisooxazol group. It is shown that the obtained new molecule called GC8 exhibits light absorption in the visible, between 400 nm and 700 nm and a high hole mobility of 210-5 cm2V- 1s- 1, which places this organic donor among those with good mobility in this family of compounds. It behaves as electron donor in organic photovoltaic cells, with a HOMO of 5.35 eV, a LUMO of 2.94 eV which gives a band gap of 2.41 eV, these values being obtained from theoretical estimation using TD-DFT theory. The measured experimental optical band gap is 1.9 eV, this difference in value between theory and experiment is reasonable for small molecules. GC8 has been introduced as electron donor in planar heterojunctions organic photovoltaic cells (PHJ-OPVs), fullerenes (C60 or C70) being used as electron acceptor. It is shown that the optimum GC8 layer thickness is 20 nm, while a 5 min annealing at 100 degrees C improves the power conversion efficiency (PCE) by 10%. The high light absorption of C70 allows improving cells performances compared to that using C60, the champion cell having a 6.15% efficiency. The PCE improvement after the annealing is due to an increase of the hole mobility and optical absorption.
- ItemFast and efficient synthesis of 2-(benzyloxy)-N,N-disubtituted-2-phenylethan-1-amines(2023) Rivero-Jerez, Paula S.; Saavedra-Olavarria, Jorge; Perez, Edwin G.A concise, metal catalyst free synthesis of 6-benzyloxyphenethylamines using the regioisomeric mixture obtained in the dialkylamine styrene oxide-ring opening products which reacted with MsCl to produce an aziridinium intermediate. This intermediate reacts, separately, with different benzyl alcohols to produce the desired products but using modern techniques such as fast heating in both steps.& COPY; 2023 Elsevier Ltd. All rights reserved.
- ItemFast Heating-Assisted One-Pot Copper-Catalyzed Sulfonylation and Sulfochlorination of Styrenes(2022) Saavedra-Olavarria, Jorge; Hermosilla-Ibanez, Patricio; Almodovar, Iriux; Perez, Edwin G.Here, a strategy for the synthesis under fast-heating conditions of vinyl sulfones and beta-chlorosulfones from styrene derivatives, tosyl chloride (TsCl) as sulfonyl and chlorine source, and CuBr-neocuproine as the catalytic system is reported. The reaction occurs through an atom transfer radical addition (ATRA) mechanism to generate the sulfochlorinated adducts followed by E2 elimination to generate the vinyl sulfones. This methodology allows a wide range of vinyl sulfones and beta-chlorosulfones to be obtained using inexpensive reagents in one and five minutes respectively. These reactions appear as an interesting fast and easy-to-handle alternative to obtain these compounds.
- ItemN-Arylation of 3-Formylquinolin-2(1H)-ones Using Copper(II)-Catalyzed Chan-Lam Coupling(2022) Valencia, Jhesua; Sanchez-Velasco, Oriel A.; Saavedra-Olavarria, Jorge; Hermosilla-Ibanez, Patricio; Perez, Edwin G.; Insuasty, Daniel3-formyl-2-quinolones have attracted the scientific community's attention because they are used as versatile building blocks in the synthesis of more complex compounds showing different and attractive biological activities. Using copper-catalyzed Chan-Lam coupling, we synthesized 32 new N-aryl-3-formyl-2-quinolone derivatives at 80 degrees C, in air and using inexpensive phenylboronic acids as arylating agents. 3-formyl-2-quinolones and substituted 3-formyl-2-quinolones can act as substrates, and among the products, the p-methyl derivative 9a was used as a substrate to obtain different derivatives such as alcohol, amine, nitrile, and chalcone.
- ItemSynthesis of N-Arylcytisine Derivatives Using the Copper-Catalyzed Chan-Lam Coupling(2021) Sanchez-Velasco, Oriel A.; Saavedra-Olavarria, Jorge; Araya-Santelices, Daniel A. A.; Hermosilla-Ibanez, Patricio; Cassels, Bruce K.; Perez, Edwin G.N-Arylcytisine derivatives are quite rare. We report here a practical methodology to obtain these compounds. Using the copper-catalyzed Chan-Lam coupling, we synthesized new N-arylcytisine derivatives at room temperature, in air and using inexpensive phenylboronic acids. Cytisine and 3,5-dihalocytisines can act as substrates, and among the products, the p-Br-derivative 2r was used as a substrate to obtain biaryl derivatives under Pd-coupling conditions; ester 2j was converted into its acid and amide derivatives using classical carbodiimide conditions. This shows that the Chan-Lam cross-coupling reaction can be included as a versatile synthetic tool in the derivatization of natural products.