Search Results (157)

A one-pot synthetic methodology that combines an Ugi-Zhu three-component reaction (UZ-3CR) with a cascade sequence (intermolecular aza Diels–Alder cycloaddition/intramolecular N-acylation/decarboxylation/dehydration) using microwave-heating conditions, ytterbium (III) triflate (Yb(OTf)₃) as the catalyst, and chlorobenzene (for the first time in a multi-component reaction (MCR)) as the solvent, was developed to synthesize twelve new fluorinated-pyrrolo[3,4-b]pyridin-5-ones containing a 4-amino-7-chloroquinoline moiety, yielding 50–77% in 95 min per product, with associated atom economies around 88%, also per product. Additionally, by in vitro tests, compounds 19d and 19i were found to effectively stop early SARS-CoV-2 replication, IC₅₀ = 6.74 µM and 5.29 µM, at 0 h and 1 h respectively, while cell viability remained above 90% relative to the control vehicle at 10 µM. Additional computer-based studies revealed that the most active compounds formed strong favorable interactions with important viral proteins (M_pro, NTDα and NTDo) of coronavirus, supporting a two-pronged approach that affects both how the virus infects the cells and how it replicates its genetic material. Finally, quantum chemistry analyses of non-covalent interactions were performed from Density-Functional Theory (DFT) to better understand how the active compounds hit the virus. Full article

The difluoromethoxy (OCF₂H) and trifluoromethoxy (OCF₃) fluorinated structural motifs are frequently seen as privileged functional groups in the field of medicinal chemistry and are regularly taken into account during the design and development processes of successful drugs. This paper presents the synthesis of four new fluorinated etheric derivatives of cannabinol (CBN) using fluorine chemistry. These reactions are straightforward in terms of operation and make use of easily obtainable reagents, making them suitable for the synthesis of various fluorinated CBN ethers with yields ranging from moderate to excellent. We successfully isolated all the products and characterized them in detail using spectroscopic methods. It is anticipated that they will increase the efficacy of drug candidates due to their ability to alter biological activities such as cellular membrane permeability and metabolic stability and improve their pharmacokinetic properties. Full article

With the rapid progression of global industrialization and urbanization, emerging contaminants (ECs) have become pervasive in environmental media, posing considerable risks to ecosystems and human health. While multidisciplinary evidence continues to accumulate regarding their environmental persistence and bioaccumulative hazards, critical knowledge gaps persist in understanding their spatiotemporal distribution, cross-media migration mechanisms, and cascading ecotoxicological consequences. This review systematically investigates the global distribution patterns of ECs in aquatic environments over the past five years and evaluates their potential ecological risks. Furthermore, it examines the performance of various treatment technologies, focusing on economic cost, efficiency, and environmental sustainability. Methodologically aligned with PRISMA 2020 guidelines, this study implements dual independent screening protocols, stringent inclusion–exclusion criteria (n = 327 studies). Key findings reveal the following: (1) Occurrences of ECs show geographical clustering in highly industrialized river basins, particularly in Asia (37.05%), Europe (24.31%), and North America (14.01%), where agricultural pharmaceuticals and fluorinated compounds contribute disproportionately to environmental loading. (2) Complex transboundary pollutant transport through atmospheric deposition and oceanic currents, coupled with compound-specific partitioning behaviors across water–sediment–air interfaces. (3) Emerging hybrid treatment systems (e.g., catalytic membrane bioreactors, plasma-assisted advanced oxidation) achieve > 90% removal for recalcitrant ECs, though requiring 15–40% cost reductions for scalable implementation. This work provides actionable insights for developing adaptive regulatory frameworks and advancing green chemistry principles in environmental engineering practice. Full article

Fluorinated organic molecules have become indispensable in modern chemistry, owing to the unique properties imparted by fluorine to other compounds, including enhanced metabolic stability, controlled lipophilicity, and improved bioavailability. The site-selective incorporation of fluorine atoms into organic frameworks is essential in pharmaceutical, agrochemical, and material science research. In recent years, catalytic fluorination has become an important methodology for the efficient and selective incorporation of fluorine atoms into complex molecular architectures. This review highlights advances in catalytic fluorination reactions over the past six years and describes the contributions of transition metal catalysts, photocatalysts, organocatalysts, and electrochemical systems that have enabled site-selective fluorination under a variety of conditions. Particular attention is given to the use of well-defined fluorinating agents, including Selectfluor, N-fluorobenzenesulfonimide (NFSI), AlkylFluor, Synfluor, and hypervalent iodine reagents. These reagents have been combined with diverse catalytic systems, such as AgNO₃, Rh(II), Mo-based complexes, Co(II)-salen, and various organocatalysts, including β,β-diaryl serine catalysts, isothiourea catalysts, and chiral phase-transfer catalysts. This review summarizes proposed mechanisms reported in the original studies and discusses examples of electrophilic, nucleophilic, radical, photoredox, and electrochemical fluorination pathways. Recent developments in stereoselective and more sustainable protocols are also examined. By consolidating these strategies, this article provides an up-to-date perspective on catalytic fluorination and its impact on synthetic organic chemistry. Full article

We report the first syntheses—from commercially available 3-chloro-2-fluoroprop-1-ene (9)—of key garlic-derived compounds containing sp²-fluorine. We also report synthesis of fluoro-5,6-dihydrothiopyrans by trapping 2-fluorothioacrolein (15). Thus, difluoroallicin (12, S-(2-fluoro-2-propenyl) 2-fluoroprop-2-ene-1-sulfinothioate) is prepared by peracid oxidation of 1,2-bis(2-fluoro-2-propenyl)disulfane (11). S-2-Fluoro-2-propenyl-l-cysteine (2-fluorodeoxyalliin, 13), synthesized from cysteine and characterized by X-ray crystallography, is oxidized to its S-oxide, 2-fluoroalliin (22). The latter, with alliinase-containing powdered fresh garlic, gives a mixture of 12, allicin (1), and isomers of monofluoroallicin (23), indicating that 22 serves as a substrate for garlic alliinase. Upon heating, 12 generates transient 15, which dimerizes giving difluoro vinyl dithiins 6 and 7. Ethyl acrylate trapping of 15 affords 5- and 6-substituted 3-fluoro-5,6-dihydro-4H-thiopyrans (19 and 20). In 1,1,1,3,3,3-hexafluoro-2-propanol (HEFP) as solvent, 12 is converted into trifluoroajoene ((E,Z)-1-(2-fluoro-3-((2-fluoro-2-propenyl)sulfinyl)prop-1-en-1-yl)-2-(2-fluoro-2-propenyl)disulfane; 18). Liquid sulfur converts 11 to a (CH₂=CFCH₂)₂S_n mixture (n = 4–15), characterized by UPLC-(Ag⁺)-coordination ion spray-mass spectrometry. Full article

The widespread phase-out of long-chain per- and poly-fluoroalkyl substances (PFASs) has created an urgent need for durable, fluorine-free water-repellent finishes that match the performance of legacy chemistries while minimising environmental impact. Here, the performance of an eco-friendly hybrid organic–inorganic treatment obtained by the in situ hydrolysis–condensation of triethoxy(octyl)silane (OS) in an amino-terminated polydimethylsiloxane (APT-PDMS) aqueous dispersion was investigated. The sol was applied to plain-weave cotton and polyester by a pad-dry-cure process and benchmarked against a commercial fluorinated finish. Morphology and chemistry were characterised by SEM–EDS, ATR-FTIR, and Raman spectroscopy; wettability was assessed by static contact angle, ISO 4920 spray ratings, and AATCC 193 water/alcohol repellence; and durability, handle, and breathability were evaluated through repeated laundering, bending stiffness, and water-vapour transmission rate measurements. The silica/PDMS coating formed a uniform, strongly adherent nanostructured layer conferring static contact angles of 130° on cotton and 145° on polyester. After five ISO 105-C10 wash cycles, the treated fabrics still displayed a spray rating of 5/5 and AATCC 193 grade 7, outperforming or equalling the fluorinated control, while causing ≤5% loss of water-vapour permeability and only a marginal increase in bending stiffness. These results demonstrate that the proposed one-step, water-borne sol–gel process affords a sustainable, industrially scalable route to high-performance, durable, water-repellent finishes for both natural and synthetic textiles, offering a viable alternative to PFAS-based chemistry for outdoor apparel and technical applications. Full article

Per- and polyfluoroalkyl substances (PFASs) are a family of synthetic chemicals that were used to improve the quality of several commercial products by making them resistant to heat, oil, stains, and grease. By containing a fluorinated carbon tail and a hydrophilic head (-COOH, -SO₃H), PFASs act as surfactants that are attracted to bubble–water interfaces. Foam fractionation is the process of facilitating PFAS–air bubble interactions for the purpose of removing contaminants from tainted water. In this paper, we report on the use of foam fractionation and electrochemical oxidation (EO) under stirred batch conditions (200 mL) to remediate PFAS-contaminated water. We used radiolabeled PFOA (perfluorooctanoic acid; ¹⁴C-PFOA) as a representative surrogate to quickly screen treatment variables of flow rate, pH, temperature, and soap mass. Using radiolabeled PFASs eliminated the possibility of cross-contamination and greatly reduced analytical costs and processing time. The results showed that foam fractionation can remove 80 to 90 percent of PFOA from water within 30 min and that 90 to 100 percent of the PFOA in the concentrated foamate can be oxidized via electrochemical oxidation (-¹⁴COOH → ¹⁴CO₂). We also tested the efficacy of the combined foam fractionation–EO treatment in natural waters by spiking ¹⁴C-PFOA and a cosolvent (CTAB) into PFAS-contaminated water obtained from two field sites with divergent PFAS concentrations and differing sources of PFAS contamination (natural drainage ditch vs. WWTP). Using a larger-scale tank (3500 mL), we observed that foam fractionation was 90% effective in removing ¹⁴C-PFOA from the WWTP effluent but only 50% effective for the drainage ditch water. Regardless, EO was highly effective in oxidizing ¹⁴C-PFOA in the foamate from both sources with half-lives (T_1/2) ranging from 8.7 to 15 min. While water chemistry differences between source waters may have influenced foam fractionation and require additional investigations, tank experiments provide the first proof-of-concept experiment using ¹⁴C-PFASs that foam fractionation and electrochemical oxidation can be used in tandem to treat PFAS-contaminated water. Full article

This study employed computational methods to investigate the basicity of a series of polyfluorinated phosphanes. Results revealed an exceptionally low basicity, with the computed pK_aH values in acetonitrile approaching −30, a value significantly lower than anticipated. The good agreement between the SMD and COSMO-RS methods provided confidence in the reliability of these values. This unexpected behavior challenges conventional perceptions of phosphane basicity and deepens our understanding of the electronic effects of fluorination. The findings hold important implications for catalysis, ligand design, and main-group chemistry, where a precise comprehension of phosphane electronic properties is crucial. pK_aH(MeCN) values, gas-phase basicities, and steric parameters are reported for 14 phosphanes. Full article

Motion control of droplets undergoing collisions with solid surface is required in a number of technological and industrial situations. Droplet dynamics after lifting off is often unpredictable, leading to a major problem in many technologies that droplets move in uncontrolled and potentially undesirable ways. Herein, this work shows that well-designed surface chemistry can produce an accurate control of force transmission to impinging droplets, permitting precise controlled droplet rebounce. The non-wetting surfaces (superhydrophobic), which mimics the water-repellent mechanism of lotus leaves via micro-to-nanoscale hierarchical morphology, with patterned “defect” of extreme wettability (hydrophilic), are synthesized by photolithography using only one inexpensive fluorine-free reagent (methyltrichlorosilane). The contact line of impinging droplet during flatting and receding is free to move on the superhydrophobic region and pinned as it meets with the hydrophilic defect, which introduces a net surface tension force allowing patterned droplet deposition, controlled droplet splitting, and directed droplet rebound. The work also achieves controlled vertical rebound of impinging droplets on inclined surfaces by controlling defect’s size, impact position, and impact velocity. This research demonstrates pinning forces as a general strategy to attain sophisticated droplet motions, which opens an avenue in future explorations, such as matter transportation, energy transformation, and object actuation. Full article

A new poly(azomethine) with improved solubility was successfully prepared by the polycondensation of terephthalaldehyde and 2,2-Bis[4-(4-aminophenoxy)phenyl]-hexafluoropropane (4-BDAF) under green chemistry conditions. This new polymer containing hexafluoroisopropylidene was compared with a polymer containing isopropylidenediphenyl to study the influence of the presence of fluorine atoms on the properties of the polymer. Both were characterized by nuclear magnetic resonance (NMR), their molecular weight was measured by gel permeation chromatography (GPC), and their morphology was studied by X-ray diffraction (XRD). The two polymers obtained were soluble in most polar aprotic solvents and even in less polar solvents, which are practical and easily accessible solvents. Their thermal properties were determined by a thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). These two new polymers showed high resistance to thermal decomposition up to 490 °C, with a glass transition temperature (Tg) of 180 °C. The photophysical properties were studied by UV/Visible absorption. The polymers were doped and then deposited on cellulose filaments, an approach that made it possible to produce self-supporting conductive composites thanks to their mechanical properties. The topography of the resulting materials was characterized at submicron scales before estimating their electronic conductivity and gap energy by diffuse reflection spectroscopy. Full article

In recent years, metallodrugs have emerged as captivating and promising compounds in the fields of cancer therapy and antimicrobial agents. While noble metals have shown remarkable biological activity, increasing interest lies in utilizing more abundant and cost-effective metals in medicinal chemistry. This is primarily due to their pivotal role in biological processes and their lower cost compared to precious metals. Among these, copper(II) complexes have emerged with promising applications in medicine. Notably, copper compounds bearing Schiff bases stand out as innovative metallodrugs. They exhibit intriguing cytotoxic properties against a wide range of cancer cell lines, while also demonstrating inhibitory effects on prevalent bacterial and fungal strains. Nevertheless, research into Cu(II) complexes with Schiff bases remains of paramount interest. One strategic avenue to bolster their biological activity involves the introduction of fluorine groups into the ligands. This approach has demonstrated a significant augmentation in efficacy and selectivity, particularly in targeting cancer cells and microbial pathogens, because fluorine incorporation can improve metabolic stability and cellular uptake. This further reinforces the therapeutic potential of these metallodrugs. Thanks to these promising outcomes, research into the development of Cu(II) complexes with fluorinated Schiff bases is advancing significantly. This holds immense potential for progressing the field of medicinal chemistry, with the aim of addressing unmet clinical needs in both cancer therapy and antimicrobial treatment. This review comprehensively explores the latest advancements in Cu(II) complexes bearing fluorinated Schiff bases, encompassing diverse coordination modes. It delves into their scope and applications in cytotoxic evaluations, as well as their efficacy as antimicrobial and antifungal agents. Full article

Area-selective atomic layer deposition (AS-ALD) is a technique utilized for the fabrication of patterned thin films in the semiconductor industry due to its capability to produce uniform and conformal structures with control over thickness at the atomic scale level. In AS-ALD, surfaces are functionalized such that only specific locations exhibit ALD growth, thus leading to spatial selectivity. Self-assembled monolayers (SAMs) are commonly used as ALD inhibiting agents for AS-ALD. However, the choice of organic molecules as viable options for AS-ALD remains limited and the precise effects of ALD nucleation and exposure to ALD conditions on the structure of SAMs is yet to be fully understood. In this work, we investigate the potential of small molecule carboxylates as ALD inhibitors, namely benzoic acid and two of its derivatives, 4-trifluoromethyl benzoic acid (TBA), and 3,5-Bis (trifluoromethyl)benzoic acid (BTBA) and demonstrate that monolayers of all three molecules are viable options for applications in ALD blocking. We find that the fluorinated SAMs are better ALD inhibitors; however, this property arises not from the hydrophobicity but the coordination chemistry of the SAM. Using nanoscale infrared spectroscopy, we probe the buried monolayer interface to demonstrate that the distribution of carboxylate coordination states and their evolution is correlated with ALD growth, highlighting the importance of the interfacial chemistry in optimizing and assessing ALD inhibitors. Full article

Fluorinated nucleos(t)ide drugs have proven to be successful chemotherapeutic agents in treating various cancers. The Food and Drug Administration (FDA) has approved several drugs that fit within the fluorinated nucleoside pharmacophore, and many more are either in preclinical development or clinical trials. The addition of fluorine atoms to nucleos(t)ides improves the metabolic stability of the glycosidic bond and, in certain instances, facilitates additional interactions of nucleons(t)ides with receptors. The insertion of fluorine either on sugar or the base of nucleos(t)ides proved to enhance the lipophilicity, pharmacokinetic, and pharmacodynamic properties. Overall, the fluorine atom feeds diverse advantages to the biological profile of nucleos(t)ide analogs by improving their drug-like properties and therapeutic potential. This review article covers the often-used fluorinating reagents in nucleoside chemistry, the clinical significance of [¹⁸F]-labeled nucleosides, the synthesis and anticancer activity of FDA-approved fluoro-nucleos(t)ide drugs, as well as clinical candidates, which are at various stages of clinical development as anticancer agents. Full article