Palladium-Catalyzed Carbonylative Cyclization of 1-Alkynyl-2-iodo-d-glucal.

Cascade reactions are important synthetic tools for the synthesis of heterocyclic molecules, particularly those catalyzed by palladium. Herein, we report a palladium-catalyzed aminocarbonylative cyclization of new 1-alkynyl-2-iodo-d-glucals, which undergo a tandem carbonylative cyclization in the presence of various amine nucleophiles. A broad range of aromatic and aliphatic amines were applied as coupling partners, resulting in the selective and high-yield synthesis of glycosides fused to pyridinones.

1-Iodoglycal: A Versatile Intermediate for the Synthesis of d-Glyco Amides and Esters Employing Carbonylative Cross-Coupling Reaction.

In this study, we present the development of two catalytic processes: a Pd-PEPPSI-catalyzed aminocarbonylation and a Pd(OAc)-Xantphos-catalyzed alkoxycarbonylation of d-glycals, utilizing carbonylative cross-coupling reactions. We explored successfully various types of aromatic amines, as well as alkyl amines and amino acids, to synthesize new d-glycal amides. However, we observed limitations in the reactivity of alkyl and heteroaromatic amines.

Organoselenium Has a Potent Fungicidal Effect on Cryptococcus neoformans and Inhibits the Virulence Factors.

Cryptococcosis therapy is often limited by toxicity problems, antifungal tolerance, and high costs. Studies approaching chalcogen compounds, especially those containing selenium, have shown promising antifungal activity against pathogenic species. This work aimed to evaluate the and antifungal potential of organoselenium compounds against Cryptococcus neoformans.

Synthesis of unprotected glyco-alkynones molybdenum-catalyzed carbonylative Sonogashira cross-coupling reaction.

Herein we report a novel Mo-catalyzed carbonylative Sonogashira cross-coupling between 2-iodoglycals and terminal alkynes. The reaction displays major improvements compared to a related Pd-catalyzed procedure previously published by our group, such as utilizing unprotected sugar derivatives as starting materials and tolerance to substrates bearing chelating groups. In this work we also demonstrate the utility of the glyco-alkynone products as platform for further functionalization by synthesizing glyco-flavones Au-catalyzed 6--dig cyclization.

Novel 2-Aryloxazoline Compounds Exhibit an Inhibitory Effect on spp., Including Antifungal-Resistant Isolates.

Because of the increased resistance to currently available antifungals, fungal infections represent a significant challenge to human health. Herein, we report the synthesis of 2-aryloxazoline derivatives from the reaction between l-threonine and derivatives of salicylic or naphthoic acid. In total, 26 compounds were obtained and tested against species of , , and .

Synthesis, Structure Study, First-Principles Investigations and Luminescence Properties of Europium and Terbium Complexes.

The synthesis of 1-benzyl-2-((2-Aminoethyl) amino)-5-oxopyrrolidine-3,4-diyl diacetate (boad), an oxopyrrolidine type ligand; designed to coordinate lanthanides (Eu and Tb) to get luminescent material. The target complexes showed good photoluminescence properties, which indicate that this type of compound can be used as sensitizers having luminescence for the green (Tb) and red (Eu) emission. The obtained results revealed that sensitizer efficiency can be improved by adding ligands like acac (Eu(acac), which has also enhanced the luminescence quantum output and period for Eu ions.

Cytotoxicity of 4-substituted quinoline derivatives: Anticancer and antileishmanial potential.

Chemical modifications of quinoline moiety have been recognized as a useful strategy to development of new drugs. Here, the cytotoxicity of a set of twenty-four 4-substituted quinolines (named HTI) was screened for their antitumor and antileishmanial potential in vitro, and the underlying mechanisms investigated. HTI 21 and HTI 22 exhibited the highest cytotoxicity, being selected to the subsequent studies.

A comparative study between Cu(INA)-MOF and [Cu(INA)(HO)] complex for a click reaction and the Biginelli reaction under solvent-free conditions.

The catalytic activity of metal-organic framework Cu(INA) (INA = isonicotinate ion) and the complex [Cu(INA)(HO)] were studied in the Copper-catalyzed Azide-Alkyne Cycloaddition (CuAAC) and Biginelli reaction under solvent-free reaction conditions. The robust, efficient and eco-friendly new method allowed the preparation of a variety of 1,2,3-triazole compounds in good to excellent yields and high selectivity for the 1,4-disubstituted triazole. Moreover, for the Biginelli reaction between aldehydes, ethyl acetoacetate and urea, the corresponding dihydropyrimidinones (DHPMs) were also obtained in satisfactory yields under mild reaction conditions for both catalysts.

Indole-3-glyoxyl tyrosine: synthesis and antimalarial activity against Plasmodium falciparum.

Aim: More than 40% of the world's population, across 105 countries, live in malaria endemic areas. It is estimated that about 500 million cases of malaria and half a million deaths occur per year.

Results: Herein, we demonstrate the biological activity of indole-3-glyoxyl tyrosine against Plasmodium falciparum, which is the causal agent of the most virulent form of malaria in humans.

Synthesis of d-glyco-alkynone derivatives carbonylative Sonogashira reaction.

A carbonylative Sonogashira coupling approach to the synthesis of glyco-alkynones is described. Eighteen examples were obtained in moderate do nearly quantitative yields under mild conditions employing Mo(CO) as a safe carbon monoxide source. Functionalization of the alkynyl moiety cycloaddition with organic azides provided six examples of glyco-triazoles.

Lipid core nanoparticles as vehicle for docetaxel reduces atherosclerotic lesion, inflammation, cell death and proliferation in an atherosclerosis rabbit model.

Chemotherapeutic agents used in cancer treatment associated to nanoparticles (LDE) that mimic the composition of low-density lipoprotein and buffer their toxicity can have strong anti-atherosclerosis action, as we showed in cholesterol-fed rabbits. Here, a novel preparation of docetaxel (DTX) carried in LDE was evaluated. Eighteen rabbits were fed 1% cholesterol during 8 weeks.

Synthesis of a Tyr-Tyr Dipeptide Library and Evaluation Against Tumor Cells.

Background: Structural component of proteins and peptides, amino acids have been used as building blocks in the synthesis of more complex molecules with antitumor activity against several types of cancer.

Objective: The search for new anticancer compounds is ongoing, especially for cancers that are very aggressive and have poor prognoses, such as leukemia.

Method: Here, we report a method to synthesize Tyr-Tyr dipeptides via sonochemistry reactions followed by functionalization of these Tyr-Tyr dipeptides with Suzuki-Miyaura and Sonogashira crosscoupling reactions in good yields.

Synthesis of α-amino-1,3-dicarbonyl compounds via Ugi flow chemistry reaction: access to functionalized 1,2,3-triazoles.

The Ugi multicomponent reaction has been used as an important synthetic route to obtain compounds with potential biological activity. We present the rapid and efficient synthesis of [Formula: see text]-amino-1,3-dicarbonyl compounds in moderate to good yields via Ugi flow chemistry reactions performed with a continuous flow reactor. Such [Formula: see text]-amino-1,3-dicarbonyl compounds can act as precursors for the production of [Formula: see text]-amino acids via hydrolysis of the ethyl ester group as well as building blocks for the synthesis of novel compounds with the 1,2,3-triazole ring.

Cytotoxic effects of a novel maleimide derivative on epithelial and tumor cells.

Novel N-triazolyl maleimide derivatives were synthesized by azide-alkyne Huisgen cycloaddition (1,3-dipolar cycloaddition) and tested for cytotoxicity against a cell line derived from human melanomas SK-Mel-28 and SK-Mel-103, and human umbilical vein endothelial cell lines (HUVEC). The 4l was chose to be biologically tested due to incorporation of benzyl triazolic to the nitrogen of maleimide has not been tested before, and due the satisfactory yield. The analysis of cell metabolism, using the MTT method, showed that the compound 4l impaired cell metabolism in HUVEC only in high concentration (100µM).

Synthesis and trypanocidal activity of a library of 4-substituted 2-(1H-pyrrolo[3,2-c]pyridin-2-yl)propan-2-ols.

A library of 16 4-substituted 2-(1H-pyrrolo[3,2-c]pyridin-2-yl)propan-2-ols 17-32 has been synthesized for use in biological testing against Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. The 4-substituted 2-(1H-pyrrolo[3,2-c]pyridin-2-yl)propan-2-ols 17-32 were subjected to biological testing to evaluate their efficacy against intracellular Trypanosoma cruzi (Y strain) amastigotes infecting U2OS human cells, with benznidazole as a reference compound. The assay was performed in duplicate (two independent experiments) and submitted to High Content Analysis (HCA) for determination of trypanocidal activity.

Evaluation of toxicity on epithelial and tumor cells of biaryl dipeptide tyrosines.

We report a method to obtain biaryl dipeptide tyrosine via Suzuki-Miyaura and alkynyl dipeptide tyrosine by Sonogashira cross-coupling reactions. Analysis of the biological action of biaryl dipeptide tyrosine 4d compound showed its ability to impair the metabolism and proliferation of SK-Mel-28 human melanoma lineage cells, independently of mitochondrial membrane depolarization, apoptosis and necrosis. Moreover, 4d compound did not cause toxicity to human umbilical vein endothelial cells (HUVEC), suggesting its toxic specificity to cancer cells.

Functionalization of protected tyrosine via Sonogashira reaction: synthesis of 3-(1,2,3-triazolyl)-tyrosine.

1,2,3-Triazol tyrosines were synthesized from tyrosine alkynes that were in turn prepared via Sonogashira cross-coupling reaction. The tyrosine alkynes were subjected to click-chemistry reaction conditions leading to the corresponding 3-(1,2,3-triazolyl)-tyrosines in yields ranging from moderate to good.

Crystal structure of 1-benzyl-2-hy-droxy-5-oxopyrrolidin-3-yl acetate.

In the title compound, C13H15NO4, the oxopyrrolidin-3-yl ring has an envelope conformation, with the C atom bearing the acetate group being the flap. The acetate and phenyl groups are inclined with respect to the central ring, forming dihedral angles of 50.20 (12) and 87.

Crystal structure of 3-[2-(4-methyl-phen-yl)ethyn-yl]-2H-chromen-2-one.

The coumarin ring system in the title asymmetric alkyne, C18H12O2, is approximately planar (r.m.s.

Crystal structure of 2-(3-nitro-phen-yl)-1,3-di-thiane.

In the title compound, C10H11NO2S2, the 1,3-di-thiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the remaining four atoms. The nitro-benzene substituent occupies an equatorial position and forms a dihedral angle of 88.28 (5)° with the least-squares plane through the 1,3-di-thiane ring.

Crystal structure of 2-(3-bromo-phen-yl)-1,3-di-thiane.

In the title compound, C10H11BrS2, the 1,3-di-thiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the remaining four atoms. The bromo-benzene ring occupies an equatorial position and forms a dihedral angle of 86.38 (12)° with the least-squares plane through the 1,3-di-thiane ring.

Crystal structure of 5-(1,3-di-thian-2-yl)-2H-1,3-benzodioxole.

In the title compound, C11H12O2S2, two independent but virtually superimposable mol-ecules, A and B, comprise the asymmetric unit. In each mol-ecule, the 1,3-di-thiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the plane through the remaining four atoms. The substituted benzene ring occupies an equatorial position in each case and forms dihedral angles of 85.

Crystal structure of 3-[2-(thio-phen-3-yl)ethyn-yl]-2H-chromen-2-one.

In the title compound, C15H8O2S, the coumarin moiety is approximately planar (r.m.s.