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We present a convenient and efficient deoxygenation method for synthesizing disulfides and thioethers. The reaction involves an iodide-catalyzed reduction of methyl sulfinates or sulfoxides, respectively, employing formic acid as a stoichiometric reductant. The methodology demonstrates excellent yields and remarkable orthogonality towards other reducible functional groups. In silico explorations revealed the synergistic action of formic acid and in situ generated hydroiodic acid as Brønsted donors within a formic acid framework. This molecular arrangement activates the sulfinyl group and promotes subsequent deoxygenation. Notably, this approach enables the deoxygenation of sulfur-based functional groups using formic acid as the stoichiometric reductant without needing transition metals or strong acidic media such as hydroiodic acid. Overall, this methodology contributes to the advancement of the reduction of diverse oxygenated sulfur-containing compounds in a sustainable approach. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive overview of strategies and methodologies for reducing C−O and heteroatomic−oxygen bonds (N−O, S−O, P−O) using I2/I−, as well as other synthetically relevant bonds such as C−C, N−N, C−N, C−X, C−S. It highlights and discusses most of the mechanistic details provided by the original authors. Selected examples of other halides (Br and Cl) as reductants are also covered. [ABSTRACT FROM AUTHOR]

Two-dimensional liquid foam systems comprised of an odd number N of bubbles arranged in a staircase configuration are studied as they are packed within a confined straight channel. Energy minimization is employed to characterize the permitted topology and geometry of the system at equilibrium. It is known that in an infinite staircase, bubble films are flat. The configuration for a finite number of bubbles, however, deviates from that of an infinite staircase at the edges. It is known that films near the edges are not flat and structures with a few bubbles (up to N=3) are well characterized. To study what happens as more bubbles are added, and how the behaviour approaches that of an infinite staircase, structures comprised of N=[5,7,...] bubbles are studied here. For these N values, minimum and maximum bubble areas are found that can pack in a staircase configuration within a straight channel. However, for an infinite staircase and also for N=3 , there are maximum areas, but no minima. Staircases with very short films, which make the structure susceptible to break in various ways, are also identified. [ABSTRACT FROM AUTHOR]

Anisylsulfanylmethylisocyanide, Asmic, is a versatile building block whose alkylations provide a range of substituted isocyanides. The anisylsulfanyl group plays a critical role in the sequenced deprotonation‐alkylation and the subsequent sulfanyl‐lithium exchange. Complexation of the anisylsulfanyl group to BuLi in the presence of TMEDA affords a lithiated isocyanide whose alkylations generate trisubstituted isocyanides. In the absence of TMEDA, BuLi triggers cyanide expulsion to afford a transient carbene; reorientation of cyanide with attack at the carbene affords a lithiated nitrile whose alkylations afford quaternary nitriles. The complexation‐induced isocyanide‐nitrile rearrangement is exceptionally facile, occurring within 5 min at –78 °C. Detailed mechanistic and computational analyses identify the importance of chelation in the bifurcating mechanism: internal chelation favors cyanide extrusion to form a carbene whereas chelating agents favor arylsulfanyl‐lithium exchange to generate a lithiated isocyanide. The combined experimental and computational analyses reveal a new mechanism for isocyanide‐nitrile isomerization which provides valuable insight for rapidly assembling substituted isocyanides. [ABSTRACT FROM AUTHOR]

Staphylococcus epidermidis is a gram-positive bacterium, and one of the most prevalent causes of nosocomial infections due to its strong ability to form biofilms on catheters and surgical implants. Here we explore the antimicrobial properties of Tet-124 peptides, which are part of the innate defense against different multicellular organisms in nature. Two different Tet-124 peptides were immobilized on a polyethylenimine (PEI) film to determine their impact on the antimicrobial properties: KLWWMIRRW (Tet-124), which contains only natural amino acids, and KLWWMIRRWG-(F-Br)-G (F-Br = 4-Bromophenylalanine), a modified Tet-124 sequence with the addition of an unnatural amino acid. The immobilization was obtained as a result of the electrostatic interaction between PEI amino groups and the C-terminal carboxylic groups of tryptophan and glycine amino acids of Tet-124 and Tet-124-Br peptides, respectively. The process was monitored and studied by water contact angle, Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and Quartz Crystal Microbalance with Dissipation (QCM-D) measurements. The antibacterial effect of our samples against S. epidermis was evaluated by the spread plate counting method, and cytotoxicity was tested using fibroblast cultures. Our results indicate the feasibility to immobilize electrostatically both Tet-124 peptides for biomedical applications. [ABSTRACT FROM AUTHOR]

Isocyanides are exceptional building blocks, the wide deployment of which in multicomponent and metal-insertion reactions belies their limited availability. The first conjugate addition/alkylation to alkenyl isocyanides is described, which addresses this deficiency. An array of organolithiums, magnesiates, enolates, and metalated nitriles add conjugately to β- and β,β-disubstituted arylsulfonyl alkenyl isocyanides to rapidly assemble diverse isocyanide scaffolds. The intermediate metalated isocyanides are efficiently trapped with electrophiles to generate substituted isocyanides incorporating contiguous tri- and tetra-substituted centers. The substituted isocyanides are ideally functionalized for elaboration into synthetic targets as illustrated by the three-step synthesis of γ-carboline N-methyl ingenine B. [ABSTRACT FROM AUTHOR]

Isocyanides are exceptional building blocks, the wide deployment of which in multicomponent and metal-insertion reactions belies their limited availability. The first conjugate addition/alkylation to alkenyl isocyanides is described, which addresses this deficiency. An array of organolithiums, magnesiates, enolates, and metalated nitriles add conjugately to β- and β,β-disubstituted arylsulfonyl alkenyl isocyanides to rapidly assemble diverse isocyanide scaffolds. The intermediate metalated isocyanides are efficiently trapped with electrophiles to generate substituted isocyanides incorporating contiguous tri- and tetra-substituted centers. The substituted isocyanides are ideally functionalized for elaboration into synthetic targets as illustrated by the three-step synthesis of γ-carboline N-methyl ingenine B. [ABSTRACT FROM AUTHOR]

In recent years, a common strategy, to obtain more uniform and controlled synthesis of polyelectrolytes multilayers (PEMs), relies on a previous polyethylenimine (PEI) coating of the substrate surface. PEI is a synthetic cationic polymer which provides a positive charge distribution on the materials to be covered with PEMs. Despite being an important step, this pre-layer deposition is frequently overlooked and no comprehensive characterizations or deep discussions are reported in literature. In that sense, this work reports on the synthesis of a typical PEI film that works as a precursor for PEMs, and its detailed physicochemical characterization. As many PEMs are produced for antibacterial and biomedical applications, the cytotoxicity of the film was also tested using fibroblasts, and its antibacterial activity was studied using Staphylococcus aureus and Pseudomonas aeruginosa . Our results present the formation of an ultra-thin film of PEI with a thickness around 3.5 nm, and with a significant percent of NH 3 + (35% of the total amount of N) in its chemical structure; NH 3 + is a key chemical group because it is considered an important bacterial killer agent. The film was stable and did not present important cytotoxic effect for fibroblasts up to 7 days, contrary to other reports. Finally, the PEI film showed high antibacterial activity against the S. aureus strain: reductions in cell density were higher than 95% up to 24 h. [ABSTRACT FROM AUTHOR]

Copper iodide catalyzes the conjugate addition of organometallic and heteroatom nucleophiles to isocyano enones to afford oxazoles. A range of enolates, metalated nitriles, amines, and thiols undergo catalyzed conjugate addition to cyclic and acyclic oxoalkene isocyanides. Mechanistic studies suggest that copper complexation facilitates the nucleophilic attack on the isocyano enone to generate an enolate that cyclizes onto the isocyanide leading to a variety of substituted acyclic or ring-fused oxazoles. [ABSTRACT FROM AUTHOR]

In the last few years, chitosan-based coatings have been proposed as antibacterial surfaces for biomedical devices in order to prevent nosocomial infections. In that sense, this work reports the optimized synthesis of hyaluronan/chitosan (HA/CHI) nanofilms assembled layer-by-layer in order to maximize the antibacterial effect for two important human pathogenic bacteria, Staphylococcus aureus and Pseudomonas aeruginosa . In this assembly, HA forms a soft, highly hydrated, and nontoxic film, whereas CHI shows the antimicrobial characteristics. Our HA/CHI nanofilm synthesis optimization was based on changing pH values of the biopolymer stem-solutions and the consequent variation of their ionization degree. Furthermore, the surface density of primary amino groups, which are related to the antibacterial effect, was also enhanced by increasing the number of HA/CHI bilayers. The antibacterial effect of HA/CHI nanofilms was evaluated by the spread plate counting method for both bacteria. These results were correlated with the morphology of nanofilms (characterized using SEM and AFM), as well as with their chemical properties studied by UV–vis, Kelvin Probe Force microscopy and XPS spectroscopy. [ABSTRACT FROM AUTHOR]

Alkyl sulfinates function as formal nucleophiles in Mannich-type reactions to give sulfonyl formamides, which are readily dehydrated to the corresponding sulfonylmethyl isonitriles. The efficient, two-step synthesis provides a general route to sulfonylmethyl isonitriles from readily available methyl sulfinates or thiols. Mechanistic analysis reveals that the unusual nucleophlicity of the alkyl sulfinates arises from the in situ release of sulfinic acids. [ABSTRACT FROM AUTHOR]

Highlights: [•] PSi layers were stabilized by H2O2 and functionalized by β-CD in-situ polymerization. [•] Physicochemical characterization of PSi/β-CD hybrids was fairly exhaustive. [•] Results showed that PSi/β-CD hybrids were functional for drug delivery applications. [Copyright &y& Elsevier]

Abstract: Porous silicon (PSi) provides an excellent platform for bioengineering applications due to its biocompatibility, biodegradability, and bioresorbability. However, to promote its application as bone engineering scaffold, deposition of calcium phosphate (CaP) ceramics in its hydroxyapatite (HAP) phase is in progress. In that sense, this work focuses on the synthesis of CaP/PSi composites by means of two different techniques for CaP deposition on PSi: Cyclic Spin Coating (CSC) and Cyclic Electrochemical Activation (CEA). Both techniques CSC and CEA consisted on alternate Ca and P deposition steps on PSi. Each technique produced specific morphologies and CaP phases using the same independent Ca and P stem-solutions at neutral pH and at room temperature. The brushite (BRU) phase was favored with the CSC technique and the hydroxyapatite (HAP) phase was better synthesized using the CEA technique. Analyses by elastic backscattering spectroscopy (EBS) on CaP/PSi structures synthesized by CEA supported that, by controlling the CEA parameters, an HAP coating with the required Ca/P atomic ratio of 1.67 can be promoted. Biocompatibility was evaluated by bone-derived progenitor cells, which grew onto CaP/PSi prepared by CSC technique with a long-shaped actin cytoskeleton. The density of adhered cells was higher on CaP/PSi prepared by CEA, where cells presented a normal morphological appearance and active mitosis. These results can be used for the design and optimization of CaP/PSi composites with enhanced biocompatibility for bone-tissue engineering. [Copyright &y& Elsevier]

In the last decade, hyaluronan (HA, polyanion) and chitosan (CHI, polycation) biopolymers have been assembled by layer-by-layer (LbL) for the synthesis of antibacterial coatings. As electrostatic interactions are the main driving force for the formation of LbL films, pH and ionic strength (IS) are important critical variables of synthesis. In this context, we used surface fractal analysis of HA/CHI films to characterize the growth process for different bilayers obtained with two pH (5 and 3) and IS values (0 and 0.1 M NaCl). Our results showed that the HA/CHI assembling is mainly affected by changes in the pH than IS. Fractal dimension (D f) of pH 5 series presented values ~2.2, indicating that irregularities from the initial random adsorption process are minimized. However, when pH decreased to 3, D f increases up to ~2.5, suggesting a transition to diffusion-limited aggregation. Image 1 • Fractal analysis was performed on HA/CHI thin films assembled by LbL. • The study was focused on the effect of pH (5 and 3) and IS (0 and 0.1 M NaCl). • Results showed that pH is the main driving force behind the morphology formation. • The growth at pH 5 consisted on aggregation accompanied by rearrangement of molecules. • The growth regime at pH 3 changed to a diffusion-limited (DLA). [ABSTRACT FROM AUTHOR]

Background: Diabetes Mellitus is a disease affecting all ages, including the pediatric population. Interventions focused on diabetes self-management (DSM) include individual education and group education. The purpose of this project was to determine if there were improvements in Hemoglobin Ale (HbAlc) between patients who only received diabetes education at diagnosis, compared to patients who additionally attended a group diabetes education program. Methods: Secondary de-identified data were obtained from electronic medical records for patients 2-18 years of age between the years 2010-2015 providing type of diabetes, HbAlc (4 consecutive readings) and class attendance, independent Samples t-tests, chi-square test and one-way ANOVA test were used to determine statistically significant differences and associations between relevant groups. Results: Data from 263 patients were analyzed to measure change in HbAlc from diagnosis to after 1 year of treatment. There was a moderately strong association between type of diabetes (type 1 and type 2) and whether or not patients attended a diabetes education class, phi = 0.266, p = 0.000016. The mean change in HbAlc was significantly greater (p<.0005) for the group of patients attending the class (-3.53±2.31) compared to those who did not (-1.39±2.41%). Mean change in HbAlc between groups by the type of diabetes was significantly greater (p=.001) in the type 1 diabetes group compared to type 2 diabetes group. Conclusions: Providing additional diabetes education post-diagnosis was associated with an increased improvement in DSM, as observed by change in HbAlc. Additional research identifying other factors toward improving DSM in this population is worth pursuing. [ABSTRACT FROM AUTHOR]

Highlights from the article: Front Cover: Asmic Isocyanide-Nitrile Isomerization-Alkylations (Eur. J. Org. After Asmic is decorated through alkylations (the gymnast on the left), an isocyanide to nitrile isomerization is triggered by the use of I n i BuLi, expelling a transient carbene which receive a reoriented cyanide to afford a lithiated nitrile, whose alkylation leads to a quaternary nitrile (the gymnast with a winning stance on the right). After Asmic is decorated through alkylations (the gymnast on the left), an isocyanide to nitrile isomerization is triggered by the use of I n i BuLi, expelling a transient carbene which receive a reoriented cyanide to afford a lithiated nitrile, whose alkylation leads to a quaternary nitrile (the gymnast with a winning stance on the right).

We present a novel deoxygenation method for heterocyclic Noxides utilizing iodide as a catalyst. Iodide acts as a reducing catalyst that is regenerated by formic acid, which also serves as a Brønsted activator and solvent. The method demonstrates high efficiency and excellent selectivity in the reduction of a variety of heterocyclic N-oxides and tertiary amines. Our computational DFT investigation revealed that the reduction mechanism entails a direct interaction between iodide and the oxygen of the N-oxide within a Mg2+/formic acid framework, resulting in the formation of the N-heterocycle and the release of a hypoiodite unit. Additionally, a molecular mechanism for the regeneration of iodide from hypoiodite, facilitated by formic acid, is suggested. This method provides an environmentally friendly approach for the deoxygenation of N-oxides and related species. [ABSTRACT FROM AUTHOR]

The modular and rapid synthesis is based on the reaction of various acyclic and 6-7-membered isocyano enones with diverse carbon or heteroatom nucleophiles such as dicarbonyl compounds, malonitrile, nitromethane, benzylamine and 4-methylbenzenethiol. [ABSTRACT FROM AUTHOR]

An abstract of the article "Alkyl Sulfinates: Formal Nucleophiles for Synthesizing TosMIC Analogues" by J. A. Lujan-Montelongo et al. is presented.

The deoxycyanation of ketones is an uncommon reaction. Recently, we demonstrated that alkyl cyanoformates, such as methyl cyanoformate (Mander's reagent) or ethyl cyanoformate, can perform deoxycyanation on 1,3-diketones to deliver oxoalkenenitriles directly. This represents a significant departure from the typical reactivity of these reagents, which are predominantly used for the synthesis of β-ketoesters (α-acylation). By transitioning from lithium bases to amine-based bases, the selectivity of the acylation shifts from carbon to oxygen, yielding an enol carbonate intermediate. Density Functional Theory (DFT) investigations and in vitro experiments corroborate the synthetic outcome, namely, the synthesis of oxonitriles via deoxycyanation. The reaction mechanism was studied, revealing a series of sequential additions and eliminations consistent with the mechanistic proposal for the generation of a major byproduct, which poses one of the main drawbacks of this method. Although this approach was proven to be non-general, it represents the first direct synthesis of oxoalkenenitriles through a deoxycyanation process, thereby deviating from the conventional C -selective applications of alkyl cyanoformates. [Display omitted] [ABSTRACT FROM AUTHOR]

Ethyl cyanoformate and methyl cyanoformate (Mander's reagent) are both routinely used to perform C-selective ketone alkoxycarbonylations. Interestingly, both reagents were found to yield oxoalkenenitriles through an unprecedented deoxycyanation of 1,3-dicarbonyl compounds (e.g., 2-methylcyclohexane-1,3-dione). Although this method is not general, this is the first time that both Mander's reagent and ethyl cyanoformate have been used for the deoxycyanation of 1,3-dicarbonyl compounds for the preparation of synthetically useful oxoalkenenitriles. Limitations on the substrate scope of the present method are discussed. [ABSTRACT FROM AUTHOR]

The combination of chitosan (C) with alginate (A) has been explored for the production of dressings due to the positive results on wound healing. CA films can show a dense or porous flexible structure, with characteristics tunable for different applications. Porosity and flexibility can be achieved, respectively, by the addition of surfactants such as Kolliphor® P188 (P) and silicone-based compounds as Silpuran® 2130 A/B (S). Furthermore, composite matrices of these polysaccharides have potential applications as devices for releasing bioactive compounds to skin lesions. The purpose of this study was to evaluate the physicochemical and biological characteristics of flexible dense and porous CA membranes incorporating the standardized extract of Arrabidaea chica Verlot (A. chica), and also to analyze the release mechanism of the extract from different membrane formulations. The results show that the inclusion of P in the formulation allows obtaining porous matrices, promotes greater homogeneity of the mixture of the silicone gel with the suspension of polysaccharides, and increases the swelling of the polymer matrix. All formulations presented high stability, reaching a maximum mass loss of 18% after seven days. The formulations with S showed the best performance in terms of flexibility and strain at break. The presence of A. chica standardized extract did not affect negatively the characteristics of the membranes. Incorporation efficiencies of the bioactive compound above 87% were achieved, and the addition of P and S to the membrane formulation changed the release of the A. chica extract kinetics. In addition, the developed formulations did not significantly affect Vero cells proliferation. • Flexible, dense and porous chitosan-alginate wound dressings were produced. • Standardized extract of A. chica Verlot was added to improve their bioactivity. • The extract was incorporated with efficiencies above 87%, without negative effects. • The concentration of A. chica extract released fitted within the therapeutic range. • None of the formulations showed significant toxicity to Vero cells. [ABSTRACT FROM AUTHOR]

Carotenoids represent a wide group of biologically active molecules found in nature with important applications in the food, cosmetics, and pharmaceutical industries. For example, lutein and its isomers meso‐ and trans‐zeaxanthin are globally the best‐selling carotenoids in terms of market value owing to their benefits to eye health. Here, the development of a solvent‐free mechanochemical epimerization protocol to convert naturally occurring lutein into 3′‐epilutein‐enriched mixtures (up to dr 37:63 lutein/3′‐epilutein) by using a strongly acidic cation‐exchange resin as an “eco‐friendly” catalyst is reported. [ABSTRACT FROM AUTHOR]

Abstract: Diastereoselective alkylation of prochiral oxonitrile dianions with secondary alkyl halides efficiently installs two contiguous stereogenic centers. The confluence of nucleophilic trajectory and the electrophile chirality causes distinct steric differences that allow efficient discrimination for one of the six possible conformers. Numerous oxonitrile‐derived dianions efficiently displace secondary alkyl halides propagating the electrophile chirality to efficiently install two contiguous tertiary centers. The prevalence of chiral, secondary electrophiles makes the interdigitated alkylation of chiral electrophiles a particularly attractive route because the resulting oxonitriles are readily transformed into bioactive heterocycles. [ABSTRACT FROM AUTHOR]

A rapid and facile method provides a general route to sulfonyl bromides/chlorides by the oxidation of thiols using NXS – ROH (X = Br,Cl, R = i Pr) as an oxyhalogenation reagent. Control experiments suggest that the alcohol component is the source of oxygen. The proposed method enable the access to structurally diverse sulfonyl bromides and chlorides including challenging examples, inaccessible by other synthetic methods. [ABSTRACT FROM AUTHOR]

A simple, microscale experiment was developed with the aim of demonstrating the concept of umpolung in synthetic organic chemistry. Starting from a common alkyl sulfinate, students perform a polarity inversion by performing a Grignard-based sulfoxide synthesis and a Mannich-type formamide synthesis. The products are purified without chromatography and are easily characterized. Procedural optimization established an experiment time of less than 3 h. Spectroscopic characterization includes the interpretation of ¹H NMR, 13C NMR, and FTIR spectra. This experiment, therefore, is suitable for a mid- to upper-level undergraduate organic lab curricula for illustrating advanced synthetic methods. [ABSTRACT FROM AUTHOR]