Acrylic Derivatives Research Articles

Synthesis of polysaccharide-based block copolymers via olefin cross-metathesis

Polysaccharide-based copolymers with brush-like, graft architectures have been prepared by many investigators. In contrast, it is challenging to prepare linear polysaccharide-based block copolymers. Only a few approaches have been reported for preparation of such architectures, despite the clear application potential of renewable-based, linear block copolymers. The challenging nature of regioselective polysaccharide end-group functionalization has impeded their preparation. Herein we report a different, flexible approach to linear block copolymers, demonstrated for derivatives of renewable, natural cellulose. To illustrate this approach, trimethyl cellulose-b-poly(ethylene glycol), trimethyl cellulose-b-poly(tetrahydrofuran) and trimethyl cellulose-b-poly(lactic acid) were synthesized by a coupling strategy. Trimethyl cellulose was functionalized regiospecifically at the reducing end anomeric carbon to create an ω-unsaturated alkyl acetal by solvolysis of trimethyl cellulose with an ω-unsaturated alcohol. Subsequently, mild and versatile olefin cross-metathesis was used to couple efficiently (100% conversion) the trimethyl cellulose block with a series of acrylate derivatives, including acrylated polymer blocks. The targeted block co-polymeric structures were confirmed by nuclear magnetic resonance (NMR) spectroscopy, and the degree of polymerization was relatively well-preserved during the coupling step, as shown by size exclusion chromatography (SEC). The results confirm that this new solvolysis/cross-metathesis method is a promising approach to polysaccharide-based linear AB, and likely ABC, block copolymers.

Mizoroki–Heck Cross‐Coupling of Acrylate Derivatives with Aryl Halides Catalyzed by Palladate Pre‐Catalysts

The Mizoroki–Heck (MH) reaction involving aryl halides with various acrylates and acrylamides has been studied using air and moisture‐stable imidazolium‐based palladate pre‐catalysts. These pre‐catalysts can be converted into Pd‐NHC species (NHC = N‐heterocyclic carbene) under catalytic conditions and are capable of facilitating the Mizoroki–Heck reaction of aryl halides with various acrylates. The effects of solvent, catalyst loading, temperature and bases on the reaction outcome have been investigated. Various coupling partners were tolerated under the optimal reaction conditions catalyzed by palladate 1, [SIPr·H][Pd(η3‐2‐Me‐allyl)Cl2]. The efficiency of the optimized synthetic methodology was tested on various aryl halides and substituted acrylates as well as acrylamides. The MH reaction yielded the coupled products in good to excellent isolated yields (up to 98%).

Ni-Catalyzed Cycloisomerization between 3-Phenoxy Acrylic Acid Derivatives and Alkynes via Intramolecular Cleavage and Formation of the C–O Bond To Give 2,3-Disubstituted Benzofurans

Reactions based on transition-metal-catalyzed C-O bond cleavage have attracted much attention as a new synthetic method. Until now, several intermolecular reactions via C-O bond cleavage of aryl ethers, alkenyl ethers, esters, and others have been reported. Here we report an unprecedented C-O bond cleavage of 3-phenoxy acrylic acid derivatives, followed by intramolecular C-O bond formation with alkynes. This reaction gave 2,3-disubstituted benzofurans having useful functional groups-silyl substituents and acrylic acid derivatives-at the 2- and 3-positions, respectively. This report also described theoretical (DFT) insights into the mechanism.

Sulfur Ylide Initiated [4 + 1]/[4 + 2] Annulation Reactions: A One-Pot Approach to Dibenzofuran Acrylate Derivatives.

A one-pot approach has been developed for the synthesis of polysubstituted dibenzofuran acrylate derivatives from (E)-2-(2-nitrovinyl)phenols, sulfur ylides, and alkynes. This protocol was carried out under mild reaction condition without any precious catalysts in generally moderate to good yields. Additionally, a plausible mechanism for the transformation was proposed.

Synthesis of Chiral β-Fluoroalkyl β-Amino Acid Derivatives via Palladium-Catalyzed Hydrogenation.

An enantioselective palladium-catalyzed hydrogenation of β-fluoroalkyl β-amino acrylic acid derivatives has been successfully developed, providing the corresponding chiral β-fluoroalkyl β-amino acid derivatives in good yields with excellent enantioselectivities. In addition, chiral γ-fluoroalkyl γ-amino alcohol could be synthesized by a simple reduction of the corresponding hydrogenated product. The mechanism of the reaction was explored by deuterium-labeling experiments.

OBTAINING SOME THERMOD AINING SOME THERMODYNAMIC PARAMETERS CONTAINING ME AINING METACRYLATE AND ALL TE AND ALLYL GROUPS CON YL GROUPS CONTAINING IN COMPOSITION

The article discusses the preparation of some thermodynamic parameters characterizing the final product of complex radical polymerization of amino alkyl acrylate derivatives containing both methacrylate and alkyl groups of low molecular weight compounds with electron acceptors - polymerization initiators at temperatures that exclude thermal decomposition of the initiators themselves. The equilibrium constant of the complication reaction and the molar extinction coefficient of the complex were determined by graphically solving the Bеneshe-Hildebrand equation, the heats of complex formation, entropy, Gibbs energy were found, and the elemental composition of low molecular weight and high molecular weight substances was determined. As can be seen from the studies, the molar extinction coefficient of the complex practically does not depend on temperature, and the equilibrium constant of the complexation reaction even in a narrow temperature range (283–293 K) increases with increasing temperature. The structure and composition of the synthesized monomeric and polymer salt were also considered in the work, and confirmed by IR-spectroscopy and analysis of elemental composition, the obtained spectroscopic data showed that the unit of the formed polymer corresponds in composition and structure to the monomeric quaternary salt, and the allyl bond in the polymers is preserved. It can be seen from the studies that, with an increase in the concentration of both the monomer and the initiator, the reaction rate naturally increases.

Iodine-mediated one-pot synthesis of C-3 acylated indolizines from pyridines, aryl methyl ketones and acrylate derivatives

An I2/CuI-promoted multi-component reaction from pyridines, aryl methyl ketones and electron deficient acrylates has been accomplished in a “one-pot” manner, which provides a straightforward and efficient access to C-3 acylated indolizines. The key intermediate of N-ylides is hypothesized to be generated in situ from pyridines and (hetero)aryl methyl ketones in the presence of iodine. This method has been applied in the synthesis of two molecules with anticonvulsant and anti-inflammatory activities.

Non-Oxidative Enzymatic (De)Carboxylation of (Hetero)Aromatics and Acrylic Acid Derivatives.

The utilization of carbon dioxide as a C1‐building block for the production of valuable chemicals has recently attracted much interest. Whereas chemical CO2 fixation is dominated by C−O and C−N bond forming reactions, the development of novel concepts for the carboxylation of C‐nucleophiles, which leads to the formation of carboxylic acids, is highly desired. Beside transition metal catalysis, biocatalysis has emerged as an attractive method for the highly regioselective (de)carboxylation of electron‐rich (hetero)aromatics, which has been recently further expanded to include conjugated α,β‐unsaturated (acrylic) acid derivatives. Depending on the type of substrate, different classes of enzymes have been explored for (i) the ortho‐carboxylation of phenols catalyzed by metal‐dependent ortho‐benzoic acid decarboxylases and (ii) the side‐chain carboxylation of para‐hydroxystyrenes mediated by metal‐independent phenolic acid decarboxylases. Just recently, the portfolio of bio‐carboxylation reactions was complemented by (iii) the para‐carboxylation of phenols and the decarboxylation of electron‐rich heterocyclic and acrylic acid derivatives mediated by prenylated FMN‐dependent decarboxylases, which is the main focus of this review. Bio(de)carboxylation processes proceed under physiological reaction conditions employing bicarbonate or (pressurized) CO2 when running in the energetically uphill carboxylation direction. Aiming to facilitate the application of these enzymes in preparative‐scale biotransformations, their catalytic mechanism and substrate scope are analyzed in this review.

Evaluating the biological potential of some new cobalt (II) complexes with acrylate and benzimidazole derivatives

This paper presents the synthesis, physico‐chemical and biological properties of four new coordination compounds with mixed ligands: acrylate ion (acr) and benzimidazole/benzimidazole derivatives with the general formula [Co(L)2(acr)2]·nH2O [(1) L: benzimidazole (HBzIm), n: 0.5; (2) L: 2‐methylbenzimidazole (2‐MeBzIm), n: 0.5; (3) L: 5‐methylbenzimidazole (5‐MeBzIm), n: 0; (4) L: 5,6‐dimethylbenzimidazole (5,6‐Me2BzIm), n: 0]. Their chemical formulae were achieved correlating the chemical analysis with mass spectrometry data, the ligands coordination modes were assigned by Fourier transform‐infrared measurements, and the trigonal bipyramidal geometry of cobalt ion in complexes was assigned by data correlation of UV–Vis‐NIR spectra and magnetic moments measurements. Single‐crystal X‐ray diffraction reveals a mononuclear structure with a pentacoordinated cobalt (II) ion, connected to two acrylato coordinated in different modes and two unidentate 5,6‐dimethylbenzimidazole ligands for compound (4). The biological tests were performed against several microbial strains, the cytotoxicity was evaluated on HCT8 cellular lines and the cell cycle analysis was performed on HT29 cellular lines. Microbiological assays indicated that Co (II) complexes present a very good to good activity against Candida albicans 1760, Enterococcus faecium E5, Bacillus subtilis ATCC 6683 and Escherichia coli ATCC 25922. Predictive pharmacokinetic (ADME), toxicity and drug‐likeness profiles were evaluated for Co (II) complexes. Our results highlight that Co (II) complexes depicted in the present study are suitable to be used as efficient pharmacological agents.

Polyacrylates Derived from Biobased Ethyl Lactate Solvent via SET-LRP.

The precise synthesis of polymers derived from alkyl lactate ester acrylates is reported for the first time. Kinetic experiments were conducted to demonstrate that Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) in alcohols at 25 °C provides a green methodology for the LRP of this forgotten class of biobased monomers. The acrylic derivative of ethyl lactate (EL) solvent and homologous structures with methyl and n-butyl ester were polymerized with excellent control over molecular weight, molecular weight distribution, and chain-end functionality. Kinetics plots in conventional alcohols such as ethanol and methanol were first order in the monomer, with molecular weight increasing linearly with conversion. However, aqueous EL mixtures were found to be more suitable than pure EL to mediate the SET-LRP process. The near-quantitative monomer conversion and high bromine chain-end functionality, demonstrated by matrix-assisted laser desorption ionization time-of-flight analysis, further allowed the preparation of innovative biobased block copolymers containing rubbery poly(ethyl lactate acrylate) poly(ELA) sequences. For instance, the poly(ELA)- b-poly(glycerol acrylate) block copolymer self-assembled in water to form stable micelles with chiral lactic acid-derived block-forming micellar core as confirmed by the pyrene-probe-based fluorescence technique. Dynamic light scattering and transmission electron microscopy measurements revealed the nanosize spherical morphology for these biobased aggregates.

Comprehensive two-dimensional liquid chromatography for the characterization of acrylate-modified hyaluronic acid.

Hyaluronic acid and its acrylate derivatives are important intermediates for various pharmaceutical, biomedical, and cosmetic applications due to their biocompatibility and viscoelasticity properties. However, these polymers are inherently difficult to characterize due to their significant heterogeneity regarding molar mass and chemical composition (degree of substitution, DS). The present study describes the development of a comprehensive online two-dimensional liquid chromatography (2D-LC) approach to characterize hyaluronic acid and its acrylate derivatives (DS ranging from 0.4 to 3.1) in terms of molar mass and degree of substitution. In the first dimension of the 2D-LC method, separation according to chemical composition/DS was achieved by using a stepwise solvent gradient and a reversed phase C8 column. Fractions from the first dimension were automatically transferred to the second dimension comprising size exclusion chromatographic separation of the fractions according to molar mass. It was found that the hyaluronic acid derivatives were broadly distributed with regard to both chemical composition and molar mass. Fractions with different degrees of substitution were identified, and their molar mass distributions were determined. The study proved that comprehensive 2D-LC is a powerful approach to reveal the complex nature of hyaluronic acid and its derivatives. Graphical abstract.

Rhodium(III)-Catalyzed Intramolecular Annulations of Acrylic and Benzoic Acids to Alkynes.

Rh(III) catalysts can promote a formal (4 + 2) intramolecular oxidative annulation between acrylic or benzoic acid derivatives and alkynes. The reaction, which involves a C–H activation process, allows for a rapid assembly of appealing bicyclic pyran-2-ones and tricyclic isocoumarin derivatives in moderate to good yields. The α-pyrone moiety of the products provides for further manipulations to obtain relatively complex cyclic skeletons in a very simple manner.

Tuning Molecular Solar Thermal Properties by Modification of a Promising Norbornadiene Photoswitch

Carefully targeted modifications to the norbornadiene‐quadricyclane couple should give molecules with great potential for solar energy storage. Here we report the synthesis of derivatives of a well‐studied compound, 2‐cyano‐3‐anisyl norbornadiene (NBD5). The conjugation was extended by conversion of the nitrile into acrylonitrile and acrylate derivatives over two steps. Despite red‐shifting the absorbance properties, the metastable quadricyclanes exhibited extremely short lifetimes. Meanwhile, treatment of NBD5 with acetyl halides in the presence of aluminum trihalides led to the formation of 7‐acetyl norbornenes through a Wagner–Meerwein rearrangement. Subsequent transformations made it possible to synthesise norbornadienes with varying degrees of steric bulk at the 7‐position of the molecular scaffold. It was found that the bulkier this group was, the more stable the quadricyclane form. This reaction sequence allows for the synthesis of norbornadiene derivatives which are more suited to molecular solar thermal applications in domestic heating despite providing a slightly lower energy density.

Copolymers of acrylate derivatives of diphenyl sulfone and divinylbenzene as materials of \u03c0-electron donor\u2013acceptor properties

Optimalization of the synthesis of porous polymers of di(p-acrylphenyl)sulfone, (p-hydroxyphenyl-p-acrylphenyl)sulfone, and divinylbenzene is presented. Porous structure of the obtained copolymers were studied. Polymer of the most regular porous structure was chemically modified in order to obtain materials of π-electron donor–acceptor properties which can be applied as specific sorbents. The influence of modification process on their porous structures was also studied.

Enhanced chemical and physical properties of PEDOT doped with anionic polyelectrolytes prepared from acrylic derivatives and application to nanogenerators.

Acrylic monomers, 4-hydroxybutyl acrylate (HBA) and 2-carboxyethyl acrylate (CEA), were each co-polymerized with styrene sulfonate in 10 mol% ratio to synthesize two types of anionic polyelectrolytes, P(SS-co-HBA) and P(SS-co-CEA), respectively. Through oxidative polymerization, two types of PEDOT composites (PEDOT:P(SS-co-HBA) and PEDOT:P(SS-co-CEA)) were synthesized, to which the anionic templates were applied as dopants. The composites were similar to PEDOT:PSS; however, crosslinking occurred with an increase in annealing temperature after film casting, which increased the electrical conductivity and hydrophobicity. The composites were applied as electrodes to PVDF-based piezoelectric nanogenerators (PNGs) having an electrode/PVDF/electrode structure. The output voltage, current, and maximum output power of PNG-2D(60) (PEDOT:P(SS-co-HBA)) annealed at a mild temperature (60 °C) were 4.12 V, 817.3 nA, and 847.5 nW, respectively, while those of PNG-3D(60) (PEDOT:P(SS-co-CEA)) annealed at 60 °C were 3.75 V, 756.5 nA, and 716.9 nW, respectively. Thus, the composites showed 13.4% and 11.3% improvements in the maximum output power compared with that of PNG-2D & 3D(RT) dried at room temperature, respectively. These results indicated 27.4% and 7.8% improvements, respectively, compared with PNG-1D(60) in which PEDOT:PSS without any crosslinking effect was applied. The PNGs demonstrated high potential as power sources owing to their sensitivity and excellent charging voltage performance for a 1 μF capacitor.

Convenient Synthesis of Some Novel Pyridazinone‐Bearing Triazole Moieties

The chemoselective reactions of 2‐(5‐mercapto‐4‐phenyl‐4H‐[1,2,4]triazol‐3‐ylmethyl)‐6‐p‐tolyl‐4,5‐dihydro‐2H‐pyridazin‐3‐one (3) with different electrophiles were evaluated. Triazole 3 reacted with alkyl halides in the presence of triethylamine in alcohol to give the corresponding S‐substituted derivatives. On the basis of S‐chemoselective reactions of triazole 3, a series of amino acid 10a–d and dipeptide derivatives 12a–d were prepared via azide coupling of the corresponding hydrazides 9 and 15 with amino acid ester hydrochlorides, respectively. N‐Substituted triazoles 6a–c or 7a–d attached to pyridazin‐3‐one moiety were successfully formed by the reaction of 3 with activated acrylic acid derivatives or with amines. Antibacterial activities of the synthesized derivatives were investigated through correlation with Escherichia coli FabH inhibitory activities using molecular modeling docking software. The antimicrobial activity of synthesized compounds was evaluated, showing best inhibition zone for N‐substituted carboxylic acid 5a and N‐substituted nitrile 5c parallel to the molecular modeling studies.

Photochemical In-Flow Synthesis of 2,4-Methanopyrrolidines: Pyrrolidine Analogues with Improved Water Solubility and Reduced Lipophilicity.

A practical synthesis of 2,4-methanopyrrolidines was elaborated. The key synthetic step was an intramolecular photochemical [2 + 2]-cycloaddition of an acrylic acid derivative in flow. In spite of a higher molecular weight, 2,4-methanopyrrolidines were shown to have higher solubility in water and lower lipophilicity than pyrrolidines, important characteristics of bioactive molecules in drug design.

Optimization of a thermal process for the production of superabsorbent materials based on a soy protein isolate

Superabsorbent materials have found several applications in fields related to diapers, hygienic tissues or controlled-release in agriculture. In order to produce more environmentally-friendly materials, some efforts have been focused on grafting copolymerization of acrylic derivatives onto a natural compound (e.g. protein, polysaccharide). This manuscript deals with the production of biodegradable superabsorbent materials produced from a Soy Protein Isolate (SPI), in which their water absorbance capacity is modulated only through the modification of the thermal processing. Thus, SPI was blended with a plasticizer (glycerol), using a 1/1 (w/w) SPI-glycerol ratio, and then injection moulded at different mould temperatures (Tmould). Subsequently, a dehydrothermal (DHT) treatment was carried out, consisting of the storage of bioplastic produced at 50 °C in an oven for a certain period of time (tDHT). The present study demonstrated that thermal conditions (Tmould, tDHT) plays a crucial role in the formation of superabsorbent materials from protein sources like SPI. Mould temperatures as low as 70 °C resulted in materials with a water uptake which defines their superabsorbent character, as long as the tDHT selected is shorter than 10 h. Longer tDHT resulted in a tighter structure with generally higher viscoelastic properties, which was less able to swell and absorb water. A longer moulding stage also lead to a decrease in the water uptake. Thus, thermal processing parameters have been proven to modulate the superabsorbent characteristics of the materials studied, not being necessary any chemical modification of the protein source.

(E)‑phenethyl 3‑(3,5‑dihydroxy‑4‑isopropylphenyl) acrylate gel improves DNFB-induced allergic contact hypersensitivity via regulating the balance of Th1/Th2/Th17/Treg cell subsets

(E)‑phenethyl 3‑(3,5‑dihydroxy‑4‑isopropylphenyl) acrylate gels (THCA354) is a novel polyphenols acrylic acid derivative. To investigate the immunoregulatory mechanisms of THCA354, we established a mouse model of 2,4‑dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD). Responses of Th1, Th2, Th17 and regulatory T cells (Tregs) were determined by flow cytometry, reverse-transcriptase polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). Our study found that topical application of THCA354 gel could inhibit ear swelling, reduce inflammatory cell infiltration, down-regulate Th1/Th17 responses and enhance Th2/Treg responses. These findings indicated that THCA354 gel exerted its immunotherapeutic effects by modulating the balance of Th1/Th2/Th17/Treg cell subsets, suggesting that THCA354 gel could be used as a promising drug candidate for intervention of ACD.

Palladium-catalyzed synthesis of 3-trifluoromethylated 1,3-dienes from acrylate derivatives and BTP

Here we reported a Pd-catalyzed coupling reaction between acrylate derivatives and BTP (2-bromo-3,3,3-trifluoropropene) to access 3-trifluoromethylated 1,3-dienes. The reaction allows the formation of the corresponding products in good to excellent yields and moderate Z/E diastereoisomeric ratios. This method broadens the current toolbox to access 3-trifluoromethylated 1,3-dienes.