Sustainable synthesis of 1,2,3-triazoles using Cyrene as a biodegradable solvent in click chemistry.

The first successful synthesis of 1,2,3-triazoles using CyreneTM as a biodegradable and non-toxic solvent in click chemistry has been developed. In contrast to previous methods, this sustainable approach allows product isolation by simple precipitation in water, eliminating the need for organic solvent extractions and column chromatography purifications, thus minimizing waste consumption while reducing operational costs. The protocol, performed also at gram scale, has broad applicability and versatility, as shown with complex substrates like biologically active coumarins or triazole-linked bifunctional molecules.

Mechanistic insights into the base-mediated deuteration of pyridyl phosphonium and ammonium salts.

Pyridines can be deuterated at the remote sites by treatment with KOBu in DMSO- , although without discrimination between the - and -position. Herein, base-catalyzed deuterations have been studied, computationally and experimentally, using a series of pyridyl phosphonium salts with a temporary electron-withdrawing group to block the -position while increasing the acidity in the other positions.

Nicotinic Acid Derivatives As Novel Noncompetitive α-Amylase and α-Glucosidase Inhibitors for Type 2 Diabetes Treatment.

A library of novel nicotinic acid derivatives, focusing on the modification of position 6 of the pyridine ring with (thio)ether functionalities, was mostly produced through an innovative green synthetic approach (Cyrene-based) and evaluated for their α-amylase and α-glucosidase inhibitory activity. Compounds and demonstrated micromolar inhibition against α-amylase (IC of 20.5 and 58.

Total Synthesis of an Epothilone Analogue Based on the Amide-Triazole Bioisosterism.

Epothilones are 16-membered macrolides that act as microtubule-targeting agents to tackle cancer. Many synthetic analogues have been investigated for their activity, yet often based on macrolide structures. A notable exception is Ixabepilone, an azalide whose metabolic stability and pharmacokinetics are significantly improved.

Minor Cannabinoids as Inhibitors of Skin Inflammation: Chemical Synthesis and Biological Evaluation.

Despite millennia of therapeutic plant use, deliberate exploitation of 's diverse biomedical potential has only recently gained attention. Bioactivity studies focus mainly on cannabidiol (CBD) and tetrahydrocannabinol (THC) with limited information about the broader cannabinome's "minor phytocannabinoids". In this context, our research targeted the synthesis of minor cannabinoids containing a lateral chain with 3 or 4 carbon atoms, focusing on cannabigerol (CBG) and cannabichromene (CBC) analogues.

Electrochemical Synthesis of Unnatural Amino Acids Embedding 5- and 6-Membered Heteroaromatics.

Using a commercially available potentiostat, the electrochemical synthesis of unnatural amino acids bearing heteroaromatics on the lateral chain has been accomplished. This strategy exploits the side-chain decarboxylative arylation of aspartic/glutamic acid, a reaction that becomes challenging with electron-rich coupling partners such as 5- and 6-membered heteroaromatics. These rings are underrepresented in unnatural amino acids, therefore allowing a wider exploration of the chemical space, given the abundance of the aryl bromides employable in this reaction.

First total synthesis of caerulomycin K: a case study on selective, multiple C-H functionalizations of pyridines.

Caerulomycins, natural alkaloids with antimicrobial properties, have been previously synthesized starting with highly pre-functionalized building blocks or requiring many functional group manipulations. In this work, we report the first total synthesis of caerulomycin K, a diversely trifunctionalized pyridine readily assembled in three steps exploiting the recent advancements in the C-H activation of N-heterocycles.

De Novo Synthesis of Dihydrobenzofurans and Indolines and Its Application to a Modular, Asymmetric Synthesis of Beraprost.

Dihydrobenzofurans and indolines are important constituents of pharmaceuticals. Herein, we describe a novel strategy for their construction in which the aromatic ring is created through an inverse-electron demand Diels-Alder reaction and cheletropic extrusion sequence of a 2-halothiophene-1,1-dioxide with an enol ether/enamide, followed by aromatization. Unusually, the aromatization process proved to be highly challenging, but it was discovered that treatment of the halocyclohexadienes with a base effected an α-elimination-aromatization reaction.

Fatty Acid Percentage Distribution in Complex Lipids of Breast Milk From Mothers on a Low Docosahexaenoic Acid Diet.

The aim of this study was to assess the fatty acid (FA) percentage distribution in complex lipids of breast milk from mothers on a low docosahexaenoic acid (DHA) diet. We performed a descriptive, cross-sectional study of milk samples (n = 14) collected 90 days after delivery and analyzed them using gas chromatography, thin-layer chromatography, and the Fiske-Subbarow method. Complex lipid distribution was 40.

Direct Observation of Reactive Intermediates by Time-Resolved Spectroscopy Unravels the Mechanism of a Radical-Induced 1,2-Metalate Rearrangement.

Radical-induced 1,2-metalate rearrangements of boronate complexes are an emerging and promising class of reactions that allow multiple new bonds to be formed in a single, tunable reaction step. These reactions involve the addition of an alkyl radical, typically generated from an alkyl iodide under photochemical activation, to a boronate complex to produce an α-boryl radical intermediate. From this α-boryl radical, there are two plausible reaction pathways that can trigger the product forming 1,2-metalate rearrangement: iodine atom transfer (IAT) or single electron transfer (SET).

Contribution of enriched wheat flour and flour products to iron requirements in children aged 6 months to 7 years.

Introduction: Wheat flour enrichment is a public health strategy recommended to prevent micronutrient deficiencies, including iron deficiency. The objective of this study was to determine iron content in enriched wheat flour and flour products and their contribution to nutritional recommendations for children.

Population And Methods: Observational, analytical, cross-sectional study based on the total diet study method.

Highly Diastereoselective Strain-Increase Allylborations: Rapid Access to Alkylidenecyclopropanes and Alkylidenecyclobutanes.

Allylboration of carbonyl compounds is one of the most widely used methods in the stereoselective synthesis of natural products. However, these powerful transformations are so far limited to allyl- or crotylboron reagents; ring-strained substituents in the α-position have not been investigated. Such substrates would lead to an increase in strain energy upon allylboration and as such cause a significant increase in the activation barrier of the reaction.

The Role of Fatigue of Compassion, Burnout and Hopelessness in Healthcare: Experience in the Time of COVID-19 Outbreak.

Background: In the times of serious health alarm, as it is happening in the COVID-19 pandemic, burden of healthcare is likely to explode. The current pandemic is having a profound effect on all aspects of society, including mental health and physical health. In a previous study we showed interaction between compassion fatigue, burnout and workload.

Difunctionalization of C-C σ-Bonds Enabled by the Reaction of Bicyclo[1.1.0]butyl Boronate Complexes with Electrophiles: Reaction Development, Scope, and Stereochemical Origins.

Difunctionalization reactions of C-C σ-bonds have the potential to streamline access to molecules that would otherwise be difficult to prepare. However, the development of such reactions is challenging because C-C σ-bonds are typically unreactive. Exploiting the high ring-strain energy of polycyclic carbocycles is a common strategy to weaken and facilitate the reaction of C-C σ-bonds, but there are limited examples of highly strained C-C σ-bonds being used in difunctionalization reactions.

How Big is the Pinacol Boronic Ester as a Substituent?

The synthetically versatile pinacol boronic ester group (Bpin) is generally thought of as a bulky moiety because of the two adjacent quaternary sp -hydribized carbon atoms in its diol backbone. However, recent diastereoselective reactions reported in the literature have cast doubt on this perception. Reported herein is a detailed experimental and computational analysis of Bpin and structurally related boronic esters which allows determination of three different steric parameters for the Bpin group: the A-value, ligand cone angle, and percent buried volume.

Synthesis, Stability, and Biological Studies of Fluorinated Analogues of Thromboxane A.

Platelet activation results in the generation of thromboxane A (TxA), which promotes thrombus formation by further amplifying platelet function, as well as causing vasoconstriction. Due to its role in thrombus formation and cardiovascular disease, its production is the target of antiplatelet drugs such as aspirin. However, the study of TxA-stimulated cellular function has been limited by its instability ( = 32 s, pH = 7.

Enhanced Electrospinning of Active Organic Fibers by Plasma Treatment on Conjugated Polymer Solutions.

Realizing active, light-emitting fibers made of conjugated polymers by the electrospinning method is generally challenging. Electrospinning of plasma-treated conjugated polymer solutions is here developed for the production of light-emitting microfibers and nanofibers. Active fibers from conjugated polymer solutions rapidly processed by a cold atmospheric argon plasma are electrospun in an effective way, and they show a smoother surface and bead-less morphology, as well as preserved optical properties in terms of absorption, emission, and photoluminescence quantum yield.

Ring-Expansion Induced 1,2-Metalate Rearrangements: Highly Diastereoselective Synthesis of Cyclobutyl Boronic Esters.

The broad synthetic utility of organoboron compounds stems from their ready ability to undergo 1,2-migrations. Normally, such shifts are induced by α-leaving groups or by reactions of alkenyl boronates with electrophiles. Herein, we present a new strategy to induce 1,2-metalate rearrangements, via ring expansion of vinylcyclopropyl boronate complexes activated by electrophiles.

Divergent, Stereospecific Mono- and Difluoromethylation of Boronic Esters.

There is considerable interest in incorporating fluorine into agrochemicals and pharmaceuticals to improve their biological properties. Whilst a number of methods have been reported for installing CH F and CHF groups, they are mainly limited to radical reactions, which are invariably racemic. Herein, we report the divergent, stereospecific reaction of fluoroiodomethyllithium with boronic esters to give α-fluoro-boronic esters.

1,2-Boron Shifts of β-Boryl Radicals Generated from Bis-boronic Esters Using Photoredox Catalysis.

1,2-Bis-boronic esters are versatile intermediates that enable the rapid elaboration of simple alkene precursors. Previous reports on their selective mono-functionalization have targeted the most accessible position, retaining the more hindered secondary boronic ester. In contrast, we have found that photoredox-catalyzed mono-deboronation generates primary β-boryl radicals that undergo rapid 1,2-boron shift to form thermodynamically favored secondary radicals, allowing for selective transformation of the more hindered boronic ester.

Reductive α-borylation of α,β-unsaturated esters using NHC-BH activated by I as a metal-free route to α-boryl esters.

Useful α-boryl esters can be synthesized in one step from α,β-unsaturated esters using just a simple to access NHC-BH (NHC = N-heterocyclic carbene) and catalytic I. The scope of this reductive α-borylation methodology is excellent and includes a range of alkyl, aryl substituted and cyclic and acyclic α,β-unsaturated esters. Mechanistic studies involving reductive borylation of a cyclic α,β-unsaturated ester with NHC-BD/I indicated that concerted hydroboration of the alkene moiety in the α,β-unsaturated ester proceeds instead of a stepwise process involving initial 1,4-hydroboration; this is in contrast to the recently reported reductive α-silylation.

Docosahexaenoic Acid in Mature Breast Milk of Low-income Mothers.

Docosahexaenoic acid (DHA) is among the main components of synaptosomal membranes and myelin sheaths. Because DHA is essential for child neurodevelopment, breast milk DHA levels should be improved by optimizing maternal nutrition. We determined DHA percentage levels in breast milk of low-income mothers receiving care at the public healthcare sector.