Acrylate Moiety Research Articles

Selective and sensitive detection of glutathione with a novel fluorescein-based probe in fully aqueous media and its application in food samples

We devised a novel fluorescent probe, FL–T, bearing fluorescein and thienyl acrylic acid moiety, which was designed and synthesised to detect glutathione (GSH). Utilising micelle-catalysed cyclisation/elimination reaction, FL–T demonstrated exceptional sensitivity and operability in a fully aqueous solution, with a low limit of detection (LOD = 41.2 nM), and superior selectivity over cysteine (Cys), homocysteine (Hcy), H2S and other analytes. Furthermore, FL–T successfully detected GSH in fruit and vegetable samples. These findings suggest that FL–T is a promising tool for detecting GSH in various environments.

Cu(II)-Organic Coordination Polymer Networks for Persistent Nitric Oxide Release in Tumor Therapy.

Nitric oxide (NO) plays a key role in regulating the immune system by polarizing macrophages toward the proinflammatory M1 phenotype, which is beneficial for cancer immunotherapy. We developed a Cu-organic coordination polymer network to sustainably release NO from endogenous donors. This robust polymer network was constructed through a dual-interaction process: complexation and cross-linking. The carboxylate groups of deprotonated 4-((6-(acryloyloxy)hexyl)oxy)benzoic acid (BA) served as bidentate ligands for the formation of Cu(II) complexes. The acrylate moiety of BA anchored these complexes in the polymer network, forming a cross-linked film. Cu ions within the network catalytically promoted NO release from S-nitrosoglutathione, maintaining this release even after 90 days in a physiological environment. The released NO effectively polarized both resting (M0) and tumor-promoting (M2) macrophages to the M1 phenotype. With their demonstrated physiological stability and sustained NO release performance, BA-Cu films hold potential as anticancer patches capable of continuously promoting antitumoral macrophages.

Material Characterization of Silicones for Additive Manufacturing.

Three-dimensional printing is ideally suited to produce unique and complex shapes. In this study, the material properties of polysiloxanes, commonly named silicones, produced additively by two different methods, namely, multi-jet fusion (MJF) and material extrusion (ME) with liquid printing heads, are investigated. The chemical composition was compared via Fourier-transform infrared spectroscopy, evolved gas analysis mass spectrometry, pyrolysis gas chromatography coupled to mass spectrometry, and thermogravimetry (TGA). Density and low-temperature flexibility, mechanical properties and crosslink distance via freezing point depression were measured before and after post-treatment at elevated temperatures. The results show significant differences in the chemical composition, material properties, as well as surface quality of the tested products produced by the two manufacturing routes. Chemical analysis indicates that the investigated MJF materials contain acrylate moieties, possibly isobornyl acrylate linking branches. The hardness of the MJF samples is associated with crosslinking density. In the ashes after TGA, traces of phosphorus were found, which could originate from initiators or catalysts of the curing process. The ME materials contain fillers, most probably silica, that differ in their amount. It is possible that silica also plays a role in the processing to stabilize the extrusion strand. For the harder material, a higher crosslink density was found, which was supported also by the other tested properties. The MJF samples have smooth surfaces, while the ME samples show grooved surface structures typical for the material extrusion process. Post-treatment did not improve the material properties. In the MJF samples, significant color changes were observed.

Wheldone Revisited: Structure Revision Via DFT-GIAO Chemical Shift Calculations, 1,1-HD-ADEQUATE NMR Spectroscopy, and X-ray Crystallography Studies.

Wheldone is a fungal metabolite isolated from the coculture of Aspergillus fischeri and Xylaria flabelliformis, displaying cytotoxic activity against breast, melanoma, and ovarian cancer cell lines. Initially, its structure was characterized as an unusual 5-methyl-bicyclo[5.4.0]undeca-3,5-diene scaffold with a 2-hydroxy-1-propanone side chain and a 3-(2-(1-hydroxyethyl)-2-methyl-2,5-dihydrofuran-3-yl)acrylic acid moiety. Upon further examination, minor inconsistencies in the data suggested the need for the structure to be revisited. Thus, the structure of wheldone has been revised using an orthogonal experimental-computational approach, which combines 1,1-HD-ADEQUATE NMR experiments, DFT-GIAO chemical shift calculations, and single-crystal X-ray diffraction (SCXRD) analysis of a semisynthetic p-bromobenzylamide derivative, formed via a Steglich-type reaction. The summation of these data now permits the unequivocal assignment of both the structure and absolute configuration of the natural product.

A Molecular Engineering Approach to Achieve Wavelength-Selective Photorelease Using a Dynamic Photocage.

We introduce a molecular engineering strategy for wavelength-selective photorelease of alcohols and carboxylic acids, employing a dynamic photocage featuring an (E)-3-(6-acetyl-2-hydroxynaphthalen-1-yl)acrylate moiety. Initially activated by visible light (λ ≥ 410 nm), it releases alcohol, generating a second photocage. Subsequent exposure to shorter wavelengths (λ ≤ 365 nm) selectively releases carboxylic acid, albeit at a reduced rate.

Bio-based non-isocyanate poly(urea)-PEG hybrids for VOC-free waterborne dispersions and fast UV-curable film application

Poly(urethane)-acrylate hybrids are often used to yield high-performing fast UV-curable coatings thanks to their highly reactive acrylate moieties. However, they are usually manufactured from toxic and petro-based isocyanate (e.g. isophorone diisocyanate, hexamethylene diisocyanate) monomers and are dispersed in water using toxic volatile neutralization agent (e.g. triethylamine). To tackle those issues, hydrophobic and bio-based non-isocyanate poly(urea) (NIPUrea) blocks have been synthesized and coupled with hydrophilic poly(ethylene glycol) diacrylate (PEGdA) via aza-Michael reaction to yield VOC-free non-ionic waterborne NIPUrea-acrylate dispersions. Those amphiphilic NIPUrea-PEG hybrids enabled the development of low particle-size waterborne dispersions for fast UV curable films (curing time < 1 min) with high gel content (>98 %) and tunable mechanical properties.

A Dielectric Ink Combining Acrylate and Cyanate Moieties for Inkjet 3D Printing with Good Thermal Stability

A Dielectric Ink Combining Acrylate and Cyanate Moieties for Inkjet 3D Printing with Good Thermal Stability

In-situ photo-crosslinkable elastomer based on polyalphaolefin/halloysite nanohybrid

In this research, new injectable and in situ photocurable elastomeric nanohybrids have been fabricated from polyalphaolefin (PAO) resins and halloysite nanofiller. In this regard, the co-oligomerization of long α-olefin monomers (C6, C8 and C10) with alkenol counterparts was carried out via a simple cationic route to provide OH-functionalized PAOs. The newly formed PAO type copolymer resins as well as halloysite nanoclay were then equipped with photocurable CC bonds containing an acrylate moiety. After the characterization of the final chemical substances and also of the intermediate structures, experimentally and computationally by means of Density Functional Theory (DFT) calculations, the neat treated PAO and PAO/halloysite nanohybrids were subjected to a curing process by visible light irradiation (λ ∼ 475 nm, blue light). The crosslinking efficiency of the neat resins and the formed nanohybrid was evaluated using shrinkage strain–time curves and equilibrium swelling method. The suggested nanohybrid is not only biocompatible (96 % in the MTT assay), and hydrophilic (with a water contact angle of 61°), but also exhibits an easy, fast and robust curing process with great potential for coating and sealing technologies for medical devices.

Cascade radical cyclization on 3-propargyl-2-alkenyl indole gives stereoselective access to cyclohepta[b]indole over carbazole.

A protecting group-dependent diastereoselective synthesis of cyclohepta[b]indole over carbazole derivatives is developed. This strategy involves a regioselective 6-exo-trig radical cyclization-cyclopropanation-ring expansion cascade of 3-propargyl-2-alkenyl indole. The cascade radical cyclization was also performed on indole derivatives possessing alkyne, acrylate and vinylogous carbamate moieties, which delivered pyridocarbazole giving credence to the mechanistic hypothesis. Furthermore, cyclohepta[b]indole could be selectively converted to sulfone and sulfoxide as well as benzoazulenoindole via intramolecular Friedel-Crafts acylation.

Exploiting β-amino ester chemistry to obtain methacrylate-based covalent adaptable networks

In this study, β-amino ester-based covalent adaptable networks (CANs) were synthesised through aza-Michael addition of amines to methacrylates, with the aim of developing industrial products. Typically, CANs based on β-amino esters employ acrylate moieties, which are known to be toxic and hazardous to human health and the environment. Therefore, methacrylate-based networks were explored as a safer alternative to the chemistry currently in use. Network formation was monitored by following the evolution of the glass transition temperature over time and conducting soluble fraction tests. Subsequently, industrial methacrylic monomers were employed to develop an industrially relevant material, utilizing previously established curing conditions for methacrylate systems. The dynamic behaviour of the network was assessed through rheological characterisation. The material demonstrated the ability to relax applied stress at various temperatures displaying typical viscoelastic fluid behaviour, indicative of exchangeable linkages within the macromolecular architecture. Shape memory and reprocessing capability were successfully tested under appropriate thermo-mechanical stimulation. Both thermal analyses and FT-IR spectra confirmed the retention of chemical composition and material properties throughout recycling process.

Azacyclic Anchor-Enabled Cohesive Graphite Electrodes for Sustainable Anion Storage.

Advanced energy-storage devices are indispensable for expanding electric mobility applications. While anion intercalation-type redox chemistry in graphite cathodes has opened the path to high-energy-density batteries, surpassing the limited energy density of conventional lithium-ion batteries , a significant challenge remains: the large volume expansion of graphite upon anion intercalation. In this study,a novel polymeric binder and cohesive graphite cathode design for dual-ion batteries (DIBs) is presented, which exhibits remarkable stability even under high voltage conditions (>5V). The innovative binder incorporates an acrylate moiety ensuring superior oxidative stability and self-healing features, along with an azide moiety, which allows for azacyclic covalent bonding with graphite and interchain crosslinking. A simple 1-h ultraviolet treatment is sufficient for binder fixation within the electrode, leading to the covalent bond formation with graphite and the creation of a robust three-dimensional network. This modification facilitates deeper and more reversible anion intercalation, leading to improved capacity, extended lifespan, and sustainable anion storage.Thebinder design, exhibiting exceptional adhesive properties and effective stress mitigation, enables the construction of ultrathick graphite cathodes. These findings provide valuable insights for the development of advanced binders, paving the way for high-performance DIBs.

Biomass RNA for the Controlled Synthesis of Degradable Networks by Radical Polymerization.

Nucleic acids extracted from biomass have emerged as sustainable and environmentally friendly building blocks for the fabrication of multifunctional materials. Until recently, the fabrication of biomass nucleic acid-based structures has been facilitated through simple crosslinking of biomass nucleic acids, which limits the possibility of material properties engineering. This study presents an approach to convert biomass RNA into an acrylic crosslinker through acyl imidazole chemistry. The number of acrylic moieties on RNA was engineered by varying the acylation conditions. The resulting RNA crosslinker can undergo radical copolymerization with various acrylic monomers, thereby offering a versatile route for creating materials with tunable properties (e.g., stiffness and hydrophobic characteristics). Further, reversible-deactivation radical polymerization methods, such as atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT), were also explored as additional approaches to engineer the hydrogel properties. The study also demonstrated the metallization of the biomass RNA-based material, thereby offering potential applications in enhancing electrical conductivity. Overall, this research expands the opportunities in biomass-based biomaterial fabrication, which allows tailored properties for diverse applications.

Synthesis of O-Heterocycle Spiro-Fused Cyclopentaquinolinones and Cyclopentaindenes through Visible Light-Induced Radical Cyclization Reactions.

Presented herein is an effective and sustainable synthesis of O-heterocycle spiro-fused cyclopentaquinolinone and cyclopentaindene derivatives through light-driven cascade reactions of N-(o-ethynylaryl)acrylamides or 2-(2-(phenylethynyl)benzyl)acrylate with various O-heterocycles. Experimental mechanistic studies revealed that these reactions are initiated by visible light-induced radical formation from O-heterocycle and its regioselective addition onto the acrylamide or acrylate moiety followed by 6-exo-dig and 5-endo-trig cascade radical annulation, which is terminated by single electron oxidation and proton elimination. Compared with previously reported synthetic methods for similar purposes, this newly developed protocol has advantages such as a broad substrate scope, extremely mild reaction conditions, excellent atom-economy, high efficiency, and good compatibility with diverse functional groups. With all of these merits, this method is expected to find wide applications in the related research arena.

In silico screening of a series of 1,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines as potential selective inhibitors of the Janus kinase 3

Rheumatoid arthritis is a common chronic disabling inflammatory disease that is characterized by inflammation of the synovial membrane and leads to discomfort. In the current study, twenty-seven 1,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines were tested as potential selective inhibitors of the tyrosine-protein kinase JAK3 using a number of molecular modeling methods. The activity of the screened derivatives was statistically quantified using multiple linear regression and artificial neural networks. To assess the quality, robustness, and predictability of the generated models, the leave-one-out cross-validation method was applied with favorable results (Q2 = 0.75) and Y-randomization. In addition, the evaluation of the predictive ability of the established model was confirmed by means of an external validation using a composite test set and an applicability domain approach. The covalent docking indicated that the tested 1H-pyrazolo[3,4-d]pyrimidines containing the acrylic aldehyde moiety had irreversible interaction with the residue Cys909 in the active sites of the tyrosine-protein kinase JAK3 by Michael addition. The molecular dynamics for three selected derivatives (compounds 9, 12, and 18) were used to verify the covalent docking by determining the stability of hydrogen bonding interactions with active sites, which are needed to stop tyrosine-protein kinase JAK3. The results obtained showed that the tested compounds containing acrylic aldehyde moiety had favorable binding free energies, indicating a strong affinity for the JAK3 enzyme. Overall, this current study suggests that the tested compounds containing the acrylic aldehyde moiety have the potential to act as anti-JAK3 inhibitors. They could be explored further to be used as treatment options for rheumatoid arthritis. Communicated by Ramaswamy H. Sarma.

Regulating exchange dynamics in poly(β-hydrazide esters) via push-pull electronic effects towards covalent adaptable networks with fast reprocessing

Poly(β-hydrazide esters), prepared by the aza-Michael addition of a hydrazide to an acrylate moiety, have been used to accelerate the dissociation rates of dynamic aza-Michael adducts via push-pull electronic effects to create covalent adaptable networks (CANs) with faster reprocessing rates. Hydrazide precursors containing aryl groups that can conjugate with the carboxamide functionality can increase the electron density on the terminal amine of the hydrazide (push electronic effect). On the other hand, hydrazide precursors containing alkyl groups that cannot conjugate with the carboxamide will have terminal amines that are more electron-deficient since part of its electron density is donated to the carbonyl group (pull electronic effect). We used small molecule models of the CANs to show that the push electronic effect of the aryl carboxamide group accelerated the dissociation rates of the dynamic aza-Michael adducts and significantly increased the reversibility of the Michael addition. In contrast, the pull electronic effect of the alkyl carboxamide groups reduced the dissociation rates of the dynamic aza-Michael adducts. Likewise, when we examined the reprocessing of the CANs, the poly(β-hydrazide esters) with the push electronic effect had lower stress relaxation times (69–79 s) and reprocessing times than their congeners with the pull electronic effect (182–3760 s). They can be reprocessed at least 10 times when heated to 180 °C for 0.5 h. Regulating the thermal stability of the dynamic aza-Michael adducts can thus reduce the dependence of the reprocessing performance of the CANs on the boiling points of the monomers. In addition, these poly(β-hydrazide esters) show excellent heat resistance (Tg = 113 °C andTd-5% = 279 °C). Thus, the push-pull electronic effect of the carboxamide groups provides a useful strategy to regulate the reversibility of the dynamic covalent bonds to achieve thermosets that can be reprocessed rapidly.

NIR light triggered intracellular polymerization via nanoparticles containing acrylates prodrugs and azo-polymers for inhibiting cisplatin efflux for combined chemotherapy and immunotherapy

Despite the high clinical success of cisplatin, this compound is associated with insufficient intracellular uptake and quick excretion from cancer cells, resulting in poor drug efficacy. To overcome these limitations, herein, a nanoparticle formulation for efficient drug delivery and high therapeutic effect towards challenging cancer tumors by multimodal chemotherapy and immunotherapy is reported. The nanoparticles are generated upon self-assembly of a polymerizable Pt(IV) prodrug with axial acrylates, a near-infrared II polymer that can generate heat, and a thermosensitive polymer with azo bonds that can generate radicals upon exposure to heat. The nanoparticles are found with a higher cellular uptake than the molecular drug cisplatin. Upon exposure to irradiation at 1064 nm, the azo bonds are broken, and therapeutically active radicals as well as the Pt(IV) complex simultaneously released. Due to the presence of reactive acrylate moieties, the metal complex is able to undergo in-situ polymerization inside the cancer cells, resulting in the formation of a cross-linked polymeric network and therefore the retention of the cisplatin and reduction of the cisplatin efflux in the cancer cells, triggering cell death by a combination of apoptosis and immunogenic cell death. Based on these promising effects, the therapeutic efficiency is evaluated in a clinically highly challenging ovarian cancer patient-derived xenograft mouse model as well as an ID8 subcutaneous tumor-bearing C57BL/6 mouse model. This study reports on the first example of a nanoparticle delivery system with Pt(IV) prodrugs that can polymerize within cancer cells, thereby resulting in a decrease in cisplatin efflux, efficient DNA damage, and effective immunogenic response.

Collective Total Synthesis of Mavacuran Alkaloids through Intermolecular 1,4‐Addition of an Organolithium Reagent**

AbstractWe report a synthetic endeavor towards the highly strained pentacyclic caged framework of the mavacuran alkaloids which culminated with the concise total synthesis of C‐fluorocurine, C‐profluorocurine, C‐mavacurine, normavacurine, 16‐epi‐pleiocarpamine and taberdivarine H. We designed a strategy involving late‐stage construction of the D ring by Michael addition of a vinylic nucleophile to a 2‐indolyl acrylate moiety. While the intramolecular Michael addition did not succeed, we were able to perform a diastereoselective unusual intermolecular 1,4‐addition of a functionalized vinyl lithium reagent to a readily accessible Michael acceptor with the assistance of the piperidine nitrogen atom through the formation of a complex as suggested by DFT computations. Final cyclization was achieved by nucleophilic substitution to form an ammonium intermediate. The first total syntheses of C‐profluorocurine and C‐fluorocurine were finalized by the dihydroxylation of C‐mavacurine and a pinacol rearrangement, respectively.

Collective Total Synthesis of Mavacuran Alkaloids through Intermolecular 1,4-Addition of an Organolithium Reagent.

We report a synthetic endeavor towards the highly strained pentacyclic caged framework of the mavacuran alkaloids which culminated with the concise total synthesis of C-fluorocurine, C-profluorocurine, C-mavacurine, normavacurine, 16-epi-pleiocarpamine and taberdivarine H. We designed a strategy involving late-stage construction of the D ring by Michael addition of a vinylic nucleophile to a 2-indolyl acrylate moiety. While the intramolecular Michael addition did not succeed, we were able to perform a diastereoselective unusual intermolecular 1,4-addition of a functionalized vinyl lithium reagent to a readily accessible Michael acceptor with the assistance of the piperidine nitrogen atom through the formation of a complex as suggested by DFT computations. Final cyclization was achieved by nucleophilic substitution to form an ammonium intermediate. The first total syntheses of C-profluorocurine and C-fluorocurine were finalized by the dihydroxylation of C-mavacurine and a pinacol rearrangement, respectively.

Efficient Copolymerization of Ethylene with Polar Divinyl Monomer by Phosphino‐Phenolate Nickel Catalyst†

Comprehensive SummaryDirect copolymerization of olefin with polar monomers via a coordination‐insertion mechanism appears as the most efficient and attractive method to prepare functionalized polyolefins. Herein, we carried out direct copolymerization of ethylene and allyl acrylate by a bulky phosphino‐phenolate nickel catalyst, in which high‐molecular‐weight copolymers bearing polar five‐membered and six‐membered ring structures were afforded. Comprehensive NMR and FT‐IR analyses revealed multiplex structure of the obtained copolymers, in which both the noncyclic structural units bearing pendant allyl moiety (A) as well as acrylate moiety (B) and the cyclic structural units, γ‐butyrolactones (C) and δ‐valerolactone (D) were found. Exhilaratingly, the content of different structural units of the produced copolymer could be tuned by adjusting the concentration of the comonomer. Moreover, we also proved that the nickel‐based catalyst could produce related copolymers with significantly enhanced copolymer molecular weights in the copolymerization of allyl acrylate and ethylene compared with the palladium‐based catalyst under the same conditions.

Effective pretreatment for thermally-assisted hydrolysis and methylation GC-MS of intractably cross-linked acrylate copolymers

Thermally-assisted hydrolysis and methylation-gas chromatography-mass spectrometry (THM-GC-MS) using tetramethylammonium hydroxide (TMAH) is an effective approach for the characterization of condensation polymers with ester linkages such as ultraviolet (UV)-cured acrylate resins. However, for intractably cured acrylic resins, reliable structural characterization is often difficult by conventional THM-GC-MS owing to insufficient THM reactions. In this study, a pretreatment to effectively improve THM efficiency was proposed, in which the resin sample was preliminarily soaked and dissolved in a TMAH-methanol solution in a microtube. An aliquot of the TMAH solution was then introduced into the pyrolyzer at 400 °C to produce THM-GC-MS. The effectiveness of the proposed pretreatment was demonstrated using a UV-cured acrylate copolymer consisting of bulky and high-molecular weight bifunctional acrylate (9,9-Bis[4-(2-acryloyloxy ethoxy) phenyl]fluorene) and monofunctional acylate (2-(9 H-Carbazol-9-yl)ethyl acrylate) monomers, for which THM reactions did not proceed efficiently in conventional THM-GC-MS. Conversely, by the modified THM-GC-MS process with a pretreatment involving immersion at room temperature for 24 h or at 60 °C for 30 min, the characteristic decomposition products for each monomer unit were clearly observed in the chromatograms, and the copolymer composition could be precisely estimated from the relative yields of the observed decomposition products. In addition, a methyl acrylate peak, formed from unreacted acrylate moieties in the photocured copolymer, appeared in the chromatogram. Its relative yields were correlated to the double bond conversion in the cured sample. The observed results were successfully interpreted to clarify the curing process of the photocured acrylate copolymer samples.