Special Collection: XIX Brazilian Meeting on Organic Synthesis (BMOS).

In this guest editorial, Paulo H. Schneider, Diogo S. Lüdtke, and Eufrânio N.

Special Collection: The XXI Brazilian Meeting on Inorganic Chemistry.

This article is an editorial about The XXI Brazilian Meeting on Inorganic Chemistry (BMIC). The XXI Brazilian Meeting on Inorganic Chemistry is one of the most important inorganic chemistry events in Latin America. This editorial introduces the event and the papers featured in the special issue celebrating BMIC in Chemistry An Asian Journal.

Generation and capture of naphthoquinonynes: a new frontier in the development of trypanocidal quinones aryne chemistry.

The regioselective synthesis of functionalized naphthoquinones the formation and capture of naphthoquinonynes has been used to prepare trypanocidal compounds. The target compounds are functionalized on the aromatic ring, leaving the quinoidal ring intact. Using this technique, eighteen functionalized naphthoquinones were succesfull obtained, divided in two main groups: the first scope using -nucleophiles, and the second scope using pyridine -oxides, with yields up to 74%.

Electrochemical Halogenation of Naphthoquinones: A Modular and Sustainable Strategy Towards Trypanocidal Compounds.

An eco-friendly electrochemical halogenation of 2-amino-1,4-naphthoquinones has been developed. The new mild and energy efficient methodology comprises sustainable features like oxidant free and double role of the halogen source as electrolyte, originating twenty-six amino-halogenated naphthoquinoidal derivatives in good yields under mild conditions. This novel methodology permitted access to new potent trypanocidal prototypes, where six compounds were more active than benznidazole, the current market drug used in the treatment of Chagas Disease.

Isostructural Oxamate Complexes with Visible Luminescence (Eu) and Field-Induced Single-Molecule Magnet (Nd).

The search for new metal-organic compounds as candidates for quantum information processing technologies is in the spotlight. Several metal ions and organic linkers have been used to obtain such compounds. Herein, we describe the synthesis, crystal structures, and cryomagnetic properties of two air-stable isostructural neodymium(III) and europium(III) one-dimensional (1D) coordination polymers of formula [Nd(Hmpa)(DMSO)] (1) and [Eu(Hmpa)(DMSO)] (2) [Hmpa=N-(4-methylphenyl)oxamate, and DMSO=dimethylsulfoxide].

SuFEx-Functionalized Quinones via Ruthenium-Catalyzed C-H Alkenylation: A Potential Building Block for Bioactivity Valorization.

Herein, we describe the Ru-catalyzed C-H alkenylation of 1,4-naphthoquinones (1,4-NQs), resulting in 1,4-naphthoquinoidal/SuFEx hybrids with moderate to good yields. This method provides a novel route for direct access to ethenesulfonyl-fluorinated quinone structures. We conducted mechanistic studies to gain an in-depth understanding of the elementary steps of the reaction.

Photoluminescence and magnetic properties of isostructural europium(III), gadolinium(III) and terbium(III) oxamate-based coordination polymers.

Developing and investigating advanced multifunctional materials with magnetic properties as candidates for assembling spin qubits for quantum computing is imperative. A new polytopic ligand based on oxamate and aniline was used to promote the synthesis of three neutral homometallic lanthanide-coordinated polymers. New complexes with the formula {Ln(phox)(DMSO)(HO)}, where Ln = Eu (1), Gd (2), and Tb (3) [phox = -(phenyl)oxamate and DMSO = dimethylsulfoxide], were synthesized and well characterized by spectroscopic methods as well as X-ray crystallographic analysis.

Bypassing Ammonia: From N to Nitrogen Heterocycles without N Intermediates or Transition Metals.

Diboradiazene compounds, derived in one step from the boron-mediated reduction of dinitrogen (N), were treated separately with sulfur and acetic anhydride, providing heterocyclic compounds that are BN isosteres of thiophene and 1,3-oxazole, respectively. These simple reactions represent the final steps in two-step routes to complex heterocycles from N that both circumvent the need for transition metal reagents and completely bypass the traditional intermediate ammonia.

The Synthesis and Reactivity of Naphthoquinonynes.

The first systematic exploration of the synthesis and reactivity of naphthoquinonynes is described. Routes to two regioisomeric Kobayashi-type naphthoquinonyne precursors have been developed, and the reactivity of the ensuing 6,7- and 5,6-aryne intermediates has been investigated. Remarkably, these studies have revealed that a broad range of cycloadditions, nucleophile additions and difunctionalizations can be achieved while maintaining the integrity of the highly sensitive quinone unit.

Electrochemical Diselenation of BODIPY Fluorophores for Bioimaging Applications and Sensitization of O.

Invited for the cover of this issue are the groups of Holger Braunschweig at the Julius-Maximilians-Universität Würzburg, Germany and Eufrânio N. da Silva Júnior at the Universidade Federal de Minas Gerais, UFMG, Brazil. The image depicts the electrochemical synthesis of selenium-containing BODIPY molecules with lightning symbolizing the electrifying synthetic process, while the surrounding elemental chaos hints at the red-shifted absorption and emission and the transformative photophysical properties of these new compounds.

Electrochemical Diselenation of BODIPY Fluorophores for Bioimaging Applications and Sensitization of O.

We report a rapid, efficient, and scope-extensive approach for the late-stage electrochemical diselenation of BODIPYs. Photophysical analyses reveal red-shifted absorption - corroborated by TD-DFT and DLPNO-STEOM-CCSD computations - and color-tunable emission with large Stokes shifts in the selenium-containing derivatives compared to their precursors. In addition, due to the presence of the heavy Se atoms, competitive ISC generates triplet states which sensitize O and display phosphorescence in PMMA films at RT and in a frozen glass matrix at 77 K.

Selenoneine-inspired selenohydantoins with glutathione peroxidase-like activity.

Chronic diseases such as cystic fibrosis, inflammatory bowel diseases, rheumatoid arthritis, and cardiovascular illness have been linked to a decrease in selenium levels and an increase in oxidative stress. Selenium is an essential trace element that exhibits antioxidant properties, with selenocysteine enzymes like glutathione peroxidase being particularly effective at reducing peroxides. In this study, a series of synthetic organoselenium compounds were synthesized and evaluated for their potential antioxidant activities.

The crucial role of silver(I)-salts as additives in C-H activation reactions: overall analysis of their versatility and applicability.

Transition-metal catalyzed C-H activation reactions have been proven to be useful methodologies for the assembly of synthetically meaningful molecules. This approach bears intrinsic peculiarities that are important to be studied and comprehended in order to achieve its best performance. One example is the use of additives for the generation of catalytically active species.

First report of -AB-corrole derived from a lapachone derivative: photophysical, TD-DFT and photobiological assays.

In this work, the synthesis, characterization and photophysical assays of a new -AB-corrole derivative from the naturally occurring quinone are described. β-Lapachone is a naturally occurring quinoidal compound that provides highly fluorescent heterocyclic compounds such as lapimidazoles. The new -AB-corrole compound was obtained from the reaction between 2,3,4,5,6-(pentafluorophenyl)dipyrromethane and the lapimidazole bearing an aldehyde group.

Sensitive hydrazine detection and quantification with a fluorescent benzothiadiazole sensor: selective lipid droplets and imaging.

In this work, we describe the design, synthesis, characterization, photophysical evaluation, DFT calculations, and application of two novel fluorescent benzothiadiazole (BTD) sensors for hydrazine detection and quantification at the cellular and multicellular () levels. The two probes were fully characterized, and their photophysical properties were evaluated. We tested the designed fluorogenic dye (named BTD-CHO) as a selective sensor for the rapid, sensitive, and selective detection of hydrazine.

It Takes Two to Tango, Part II: Synthesis of A-Ring Functionalised Quinones Containing Two Redox-Active Centres with Antitumour Activities.

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (-quinone/-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929.

Solvent-free hydroboration of alkenes and alkynes catalyzed by rhodium-ruthenium nanoparticles on carbon nanotubes.

A heterogeneous catalyst consisting of bimetallic rhodium-ruthenium particles immobilized on carbon nanotubes was used in the hydroboration reaction and proved highly effective for a variety of alkenes and alkynes. The reactions were carried out with low catalytic loadings (0.04 mol%), under solvent-free conditions, and at room temperature.

ZIM, a Norbornene Derived from 4-Aminoantipyrine, Induces DNA Damage and Cell Death but in Association Reduces the Effect of Commercial Chemotherapeutics.

Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed.

Aryl-Phenanthro[9,10-]imidazole: A Versatile Scaffold for the Design of Optical-Based Sensors.

Fluorescent and colorimetric sensors are important tools for investigating the chemical compositions of different matrices, including foods, environmental samples, and water. The high sensitivity, low interference, and low detection limits of these sensors have inspired scientists to investigate this class of sensing molecules for ion and molecule detection. Several examples of fluorescent and colorimetric sensors have been described in the literature; this Review focuses particularly on phenanthro[9,10-]imidazoles.

Structure-Based Identification of Naphthoquinones and Derivatives as Novel Inhibitors of Main Protease M and Papain-like Protease PL of SARS-CoV-2.

The worldwide COVID-19 pandemic caused by the coronavirus SARS-CoV-2 urgently demands novel direct antiviral treatments. The main protease (M) and papain-like protease (PL) are attractive drug targets among coronaviruses due to their essential role in processing the polyproteins translated from the viral RNA. In this study, we virtually screened 688 naphthoquinoidal compounds and derivatives against M of SARS-CoV-2.

Introduction to celebrating Latin American talent in chemistry.

In celebration of the excellence and breadth of Latin American research achievements across the chemical sciences, we are delighted to present an introduction to the themed collection, Celebrating Latin American talent in chemistry.

Design, synthesis and in vivo evaluation of 1,4-dioxo-2-butenyl aryl amine derivatives as a promising anti-inflammatory drug prototype.

Inflammation is a natural response of the organism to an infection, trauma, or cellular stress. Pain is the first symptom of acute and chronic inflammation. The standard class of medication to treat inflammatory pain is the nonsteroidal anti-inflammatory drug (NSAID).

Looking deep into C-H functionalization: the synthesis and application of cyclopentadienyl and related metal catalysts.

Metal catalyzed C-H functionalization offers a versatile platform for methodology development and a wide variety of reactions now exist for the chemo- and site-selective functionalization of organic molecules. Cyclopentadienyl-metal (CpM) complexes of transition metals and their correlative analogues have found widespread application in this area, and herein we highlight several key applications of commonly used transition-metal Cp-type catalysts. In addition, an understanding of transition metal Cp-type catalyst synthesis is important, particularly where modifications to the catalyst structure are required for different applications, and a summary of this aspect is given.

Structure-based identification of naphthoquinones and derivatives as novel inhibitors of main protease Mpro and papain-like protease PLpro of SARS-CoV-2.

The worldwide COVID-19 pandemic caused by the coronavirus SARS-CoV-2 urgently demands novel direct antiviral treatments. The main protease (Mpro) and papain-like protease (PLpro) are attractive drug targets among coronaviruses due to their essential role in processing the polyproteins translated from the viral RNA. In the present work, we virtually screened 688 naphthoquinoidal compounds and derivatives against Mpro of SARS-CoV-2.