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In this paper, the synthesis of alkyl aryl ethers from electron poor phenols and amines, using 1,3-propanedinitrite, is described. Due to the mild conditions, functionalized primary, secondary, and tertiary alkyl groups were successfully introduced, denoting a highly tolerant process that allows for unprotected alcohols and acetals. The reaction is thought to proceed through the formation of a diazonium intermediate that undergoes subsequent SN2 or SN1 reactions. [ABSTRACT FROM AUTHOR]

The effect of ester gum, a widely used weighting agent, on Ostwald ripening in model beverage emulsions formulated using different food-grade surfactants was examined. A microfluidizer was used to prepare 5% orange oil-in-water emulsions stabilized by a series of ethylene glycol alkyl ether surfactants. Emulsions prepared using only orange oil exhibited an appreciable increase in droplet size during a 14-day storage, independent of surfactant type or concentration. Incorporation of ester gum into the oil phase of the emulsions effectively inhibited droplet growth at concentrations ≥20%. The inhibition of droplet growth by ester gum depended on the surfactant type (hydrophilic group size) and concentration. Overall, ester gum stabilized the emulsions by acting as an Ostwald ripening inhibitor, as well as a weighting agent. [ABSTRACT FROM AUTHOR]

Long‐chain epoxides and specifically alkyl glycidyl ethers represent a class of highly hydrophobic monomers for anionic ring‐opening polymerization (AROP), resulting in apolar aliphatic polyethers. In contrast, poly(ethylene glycol) is known for its high solubility in water. The combination of hydrophobic and hydrophilic monomers in block and statistical copolymerization reactions enables the synthesis of amphiphilic polyethers for a wide range of purposes, utilizing micellar interactions in aqueous solutions, e.g., viscosity enhancement of aqueous solutions, formation of supramolecular hydrogels, or for polymeric surfactants. Controlled polymerization of these highly hydrophobic long‐chain epoxide monomers via different synthesis strategies, AROP, monomer‐activated anionic ring‐opening polymerization, catalytic polymerization, or via postmodification, enables precise control of the hydrophilic/lipophilic balance. This renders amphiphilic polymers highly interesting candidates for specialized applications, e.g., as co‐surfactants in microemulsion systems. Amphiphilic polyethers based on propylene oxide and ethylene oxide, such as poloxamers are already utilized in many established applications due to the high biocompatibility of the polyether backbone. Long alkyl chain epoxides add an interesting perspective to this area and permit structural tailoring. This review gives an overview of the recent developments regarding the synthesis of amphiphilic polyethers bearing long alkyl chains and their applications. [ABSTRACT FROM AUTHOR]

In order to explore the gas holdup distribution of the microbubble countercurrent contact flotation column in the hematite column cationic reverse flotation process, respectively using conductance method and pressure drop method for air and water as experimental medium characteristics research of flotation column, the research group carries on the gas holdup, examines the aeration quantity, the fill medium and cation collector alkyl polyamine ether (An amine collector--GE-609 which consists of four elements: carbon, hydrogen, oxygen and nitrogen)within the column on the influence of the axial and radial gas holdup. The results show that the axial gas holdup from the bottom of the column to the top of the column increases with the increase of height in the range of 0.05-0.07dm3/s. The radial distribution of gas holdup generally shows the distribution law of "intermediate high, low on both sides". After the filling medium is added into the column, the radial gas holdup is evenly distributed compared with the empty column, and the gas holdup is increased. Due to the high foaming performance of GE-609, the gas holdup in the column can be increased by changing the amount of aeration and the concentration of the reagent, which can exceed 60% at the maximum. Like other alcohol foaming agents, as time passes, the effect of GE-609 weakens and the gas holdup in the column gradually decreases. The addition of quantitative HCl can improve the foaming performance of GE-609, and the gas holdup in the column is significantly improved and the stability is enhanced. [ABSTRACT FROM AUTHOR]

We report a C(sp3)−C(sp3) cross‐coupling of alkyl bromides and alkyl chlorides with ethers by dual photoredox‐nickel catalysis. The catalytic system comprises of the organic photocatalyst 1,2,3,5‐tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene (4‐CzIPN) and bench stable nickel (II) acetylacetonate in the presence of visible‐light, providing the coupling products in up to 92% yield. Preliminary mechanistic studies suggest two catalytic cycles, as well as the photogeneration of bromine or chlorine radicals from halide atoms that are present in the structures of the coupling partners. The halide radical mediates the hydrogen atom transfer event, avoiding the need of an additional HAT catalyst. [ABSTRACT FROM AUTHOR]

The present study deals with the use of cell-free supernatant of bacteria Morganella morganii for synthesizing copper nanoparticles and analysing its larvicidal activity on mosquito larvae. A colour change from blue to pickle green specifies the synthesis production of CuNPs. The nanoparticles were characterized using ultraviolet–visible spectrophotometry, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD pattern shows the major peaks, viz. (111), (200) and (220). SEM analysis shows that nanoparticles are in a spherical shape with a small percentage of elongated particles and size of about 13.5 ± 0.6 nm. A UV–Vis absorption peak was observed at 540 nm. FTIR analysis of nanoparticles exhibits functional groups such as aromatics, alkanes, ethers and alkyl halides. In EDaX (energy-dispersive X-ray) analysis, the peak signal confirms the presence of copper atoms that bound to the synthesized nanoparticles. The synthesized copper nanoparticles were tested for larvicidal efficacy at different time intervals. The above result shows that the copper nanoparticles produce increased toxicity in a time- and dose-dependent manner. An antibacterial and antifungal activity was tested against clinical pathogens, and the highest zone of inhibition was found to be in E. coli, B. subtilis, A. niger, M. anisopliae and Verticillium sp. This study shows that CuNPs possess a good antimicrobial and insecticidal activity which can be explored for commercial purpose. [ABSTRACT FROM AUTHOR]

Background: Acne is one of the most common skin problems among human populations. A facial cleanser formulated with alkyl ether carboxylate (AEC) and alkyl carboxylate (AC) can improve acne by cleansing sebum on facial skin but cannot effectively remove keratotic plugs in the skin pores. Recently, we confirmed that Tris (hydroxymethyl) aminomethane and L‐arginine (Tris/Arg) is able to reduce sebum levels, disrupt keratotic plugs in vitro and decrease pore size on facial skin. Objective: To compare the efficacy of the Tris/Arg‐formulated cleanser with the AEC/AC cleanser in Thai subjects with acne. Methods: We designed a randomized, double‐blind, controlled, parallel trial. Thirty‐four male Thai subjects with mild to moderate acne were assigned to one of two groups: one group used the Tris/Arg cleanser while the other used the AEC/AC‐based cleanser twice a day for 4 weeks. Results: After 4 weeks, significant decreases in noninflammatory acne were observed in both groups, yet significant decreases in inflammatory acne were only observed in the Tris/Arg cleanser group. The sebum level prior to and 30 minutes after facial washing showed no change in either group. The average pore size with keratotic plugs on the cheeks was significantly decreased in the Tris/Arg group. More than half of subjects in both groups observed acne improvement but more subjects in the Tris/Arg group noted pore size improvement. Conclusion: The Tris/Arg formulated cleanser has a high efficacy for significantly reducing both noninflammatory and inflammatory acne accompanied by decreases in pore size with keratotic plugs in male Thai subjects. [ABSTRACT FROM AUTHOR]

Direct C–H functionalization of aryl ethers remains challenging owing to their low reactivity and selectivity. Herein, a novel strategy for nondirected C–H alkenylation of aryl ethers promoted by a dual ligand catalyst was demonstrated. This catalytic system readily achieved the highly efficient alkenylation of alkyl aryl ethers (anisole, phenetole, n-propyl phenyl ether, n-butyl phenyl ether and benzyl phenyl ether), cyclic aryl ethers (1,4-benzodioxan, 2,3-dihydrobenzofuran, dibenzofuran), and diphenyl oxides. Moreover, the proposed methodology was successfully employed for the late-stage modification of complex drugs containing the aryl ether motif. Interestingly, the compounds developed herein displayed fluorescent properties, which would facilitate their biological applications. [ABSTRACT FROM AUTHOR]

Herein we report a transformation that generates an array of enantiomerically enriched, alkyl allyl ethers. Cyclic, acyclic, and heteroatom‐bearing alkenyl triflates undergo an enantioselective, palladium‐catalyzed C−C bond formation with diverse acyclic O‐alkyl enol ethers in good yields and excellent enantioselectivities. [ABSTRACT FROM AUTHOR]

Surfactants are major components of detergents and cosmetics; they are among the most undesirable pollutants in the environment because of their toxic effects on aquatic organisms. The main objective of this work is to define the elimination limits of the three different types of surfactants (anionic, cationic and amphoteric) by activated sludge. The results obtained were modeled by the model ASM1 (Activated Sludge Model N°1) in order to establish a better representation of the kinetic parameters such as the rate of disappearance of surfactant rs and the growth rate of the biomass rc. According to the classification based on biodegradation surfactants, the results obtained suggest that the AES is more degraded than the other surfactants with rs AES = 17.01 mg / lh at (cAES = 40 mg / l, T = 35 ° C) and rc AES = 1.42. mg / lh under the same conditions. [ABSTRACT FROM AUTHOR]

The first protocol for boron‐promoted ether interchange reaction of methoxynitroarenes was described. A series of methoxynitroarenes and alcohols, including primary, secondary, as well as tertiary alcohols were reacted smoothly in moderate to good yields under the optimized reaction conditions. This protocol constitutes an operationally simple and scalable strategy for the synthesis of alkyl nitroaromatic ethers. Moreover, the new reactivity of boron reagents was discovered. [ABSTRACT FROM AUTHOR]

Amine containing aryl ethers are common pharmacophore motifs that continue to emerge from drug discovery efforts. As amino alcohols are readily available building blocks, practical methodologies for incorporating them into more complex structures are highly desirable. We report our efforts to explore the application of Pd‐catalyzed C−O coupling methods to the arylation of 1,2‐ and 1,3‐amino alcohols. We established general and reliable conditions, under which we explored the scope and limitations of the transformation. The insights gained have been valuable in employing this methodology within a fast‐moving drug discovery environment, which we anticipate will be of general interest to the synthesis and catalysis communities. [ABSTRACT FROM AUTHOR]

An efficient and Brønsted acid-free route to synthesize monoterpene ethers was developed using SnBr2 as inexpensive and commercially affordable catalyst. This process consists of the synthesis of α-terpinyl alkyl ethers in SnBr2-catalyzed reactions of β-pinene with alkyl alcohols. The catalytic activity of various tin(II) salts was assessed and compared to that of other homogeneous Lewis and Brønsted acids, in etherification reactions of β-pinene with methyl alcohol. SnBr2 was the most active and selective catalyst toward α-terpinyl methyl ether. Tin(II) bromide is a water tolerant Lewis acid, which emerges as an efficient, simple, and cheap catalyst. The influence of the main reaction parameters was investigated, including SnBr2 concentration, temperature and reaction time. Different alcohols and monoterpenes were also studied. The impact of the substrate nature on the reaction selectivity was assessed. [ABSTRACT FROM AUTHOR]

Aim: To carry out the preliminary qualitative phytochemical screening of leaf extract of an Indian herb. P. foetida and Fourier Transform Infra-red Spectroscopy (FTIR) analysis of the extract containing the highest number of phytochemicals. Method: The leaf extracts were prepared using, water, methanol, ethyl acetate and acetone. Several in vitro phytochemical analyses were carried to check for the presence various secondary metabolites. FTIR analysis of all the 4 extracts were carried out of the for identifying organic secondary metabolites. Results: Ethyl acetate extract was found to be positive for most of the qualitative phytochemical screening test containing almost all the phytochemicals. The FTIR analysis revealed, that the leaf-extracts of P. foetida had phytochemicals of different functional groups such as alkanes, aromatic compounds, aldehydes, saturated fatty acids, alcohols, carboxylic acids, esters, ethers and alkyl halides Conclusion: The study concluded that, the Indian herb P. foetida is rich secondary metabolites and it can be used in the production alternative and complementary drugs, that can be against various human diseases. [ABSTRACT FROM AUTHOR]

Background. Phyto-reduction using Senna alata methanol leaf extract for nanoparticle (NP) biosynthesis is of great importance for the production of value-added nanomaterial with antimicrobial potential. Objectives. The aim of this study was to investigate the biosynthesis of zinc oxide nanoparticles (ZnONPs) using crude methanol leaf extract of S.alata (SaZnONPs), antimicrobial efficacy of this extract, optimization of its production parameters, and its application in cold cream formulation. Material and methods. Phytosynthesized SaZnONPs were characterized using UV-Vis absorption spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), X-ray diffraction (XRD) analysis, and energy-dispersive X-ray (EDX) spectroscopy. The antimicrobial activity of SaZnONPs and the formulated cold cream was evaluated. Results. The SaZnONPs surface plasmon resonance (SPR) was 400 nm. Functional groups such as alkenes, alkynes and alkyl aryl ether were present. The SEM image showed NPs 7.10 nm in size and with a needle- -like shape. The TGA values show the formations of stable ZnONPs, while the DLS showed the particle diameter average of 89.7 nm and 855.4 nm with 0.595 polydispersity index. The EDX analysis confirmed the formation of pure ZnONPs, and the crystallinity was confirmed with XRD analysis. Twenty-four hours of incubation and production at pH13 was optimal for NPs synthesis. The SaZnONPs and the formulated cold cream have antimicrobial properties against some pathogenic bacteria and Pichia sp. (16.00 mm) and Trichophyton interdigitale (11.00 mm). Conclusions. Senna alata was able to serve as a stabilizing and capping agent for SaZnONPs biosynthesis. The SaZnONPs had good antimicrobial potential and can be used in cold cream formulation. [ABSTRACT FROM AUTHOR]

• A series of bimetallic catalysts based Au-Cu supported over nanoceria were prepared. • A 80% yield to AECA6 was achieved in the oxidation reaction of AEO7 with H 2 O 2. • The formation of a AuCu alloy at a Cu/Au molar ratio of 0.11 on Au enhances the catalytic activity. • The catalyst can be recycled and reused for at least 10 consecutive runs without loss of activity. • Cu on Au favors the adsorption of AEO7, H 2 O 2 and OH− on the catalyst surface compared to pure Au. • Isolated Cu sites on the AuCu alloy appear as crucial for enhancing the catalytic activity. We describe in this work the preparation of a series of bimetallic Au-Cu catalysts supported over nanoceria for the direct oxidation of C 12 -C 14 -alcohol polyethyleneglycol ether with on average 7 ethyl oxide units (AEO7) to polyoxyethylene lauryl ether carboxylic acid (AECA6), using H 2 O 2 as an oxidant, under basic conditions. Different preparation methods have been used, including deposition-precipitation, incipient wetness impregnation and wet impregnation for engineering the interaction between Au, Cu and nanoceria. The structure of the bimetallic catalysts is discussed in detail on the basis of refined characterization by XRD, HR-TEM, STEM-EDX-SDD, XPS and ICP-AES. The formation of a AuCu alloy over nanoceria at a Cu/Au molar ratio of 0.11 on Au allows a significant enhancement of the catalytic activity, resulting in an AECA6 yield up to 80% with a selectivity of 90%. The catalyst can be recycled and reused for at least 10 consecutive runs without apparent loss of activity. Detailed DFT calculations on Au, Cu and Au-Cu model alloys reveal a positive role of Cu on Au by favoring the adsorption of AEO7, H 2 O 2 and OH− on the catalyst surface compared to pure Au, as well as by reducing the energy barrier for H 2 O 2 cleavage. Isolated Cu sites on the Au-Cu alloy appear as crucial for enhancing the catalytic properties for AEO7 oxidation. [ABSTRACT FROM AUTHOR]

Enol ethers are a fascinating product class and valuable building blocks with versatile reactivities and synthetic applications. With the emergence of silyl enol ethers, the chemistry of simple alkyl enol ethers has received less attention and targeted reviews of their chemistry are scarce. Especially intramolecular reactions under participation of an enol ether function have never been specifically surveyed. The construction of cyclic scaffolds is arguably one of the most important and challenging tasks of the organic chemist and intramolecular cyclisations represent the most straight‐forward tool to achieve this goal. The potential of enol ether‐containing substrates to form oxygenated carbo‐ and heterocycles is obvious. The purpose of this review is to discuss their particular reactivity and to direct the reader's attention to how their unique properties have been harnessed by organic chemists for the construction of rings. [ABSTRACT FROM AUTHOR]

To develop a structure-tailoring catalyst for catalytic conversion of lignin for value-added chemicals, a series of novel Fe-Ce-Al metal oxide catalysts was synthesized via different methods to tailor activity and structure for catalytic pyrolysis of lignin to enhance hydrocarbon-rich bio-oil. The results revealed that FeCeAl-CO catalysts derived from coprecipitation method with smaller particle sizes exhibited excellent catalytic deoxygenation activity due to higher Lewis/Brønsted acid, reversible Ce3+/Ce4+ redox pairs, tailorable oxygen vacancies and promoted β-O-4, aromatic-OCH 3 and side-chain cleavage. Additionally, coprecipitation method was facilitated to enhance hydrogen transfer, side-chain cleavage and aromatization reactions, while wet impregnation was beneficial to enhance demethoxylation and H-abstraction activity. During catalytic pyrolysis process, over 57.91% of hydrocarbon, including 20.21% and 25.71% for aromatics and olefins were achieved over FeCeAl-CO catalyst. Over 60.74% phenols and 52.48% alkylphenols were obtained over Fe-Ce/Al 2 O 3 -IM catalyst due to synergistic effect of FeOx and CeOx species. Fe-Ce-Al catalyst exhibited great activity and stability after fourth run, greater Brønsted acid-favored lignin cleavage and coke deposition, and metal active species leaching, oxidation and pore blockage were the key reasons for deactivation. Therefore, these findings could provide a cost-effective method for designing structure-tailoring catalysts for direct catalytic deoxygenation of lignin to generate hydrocarbon-rich upgrading bio-oil. [Display omitted] • Fe-Ce-Al exhibits a catalytic capacity for hydrocarbon-rich production by different methods. • The increase in Lewis acid, reversible Ce3+/Ce4+ redox pairs and oxygen vacancies favors deoxygenation. • Oxygen was removed by the cleavage of ether alkyl bond and other oxygenated groups. • Efficient hydrocarbon (57.91%) and olefins (25.71%) yield was achieved with coprecipitation method. • The catalyst exhibited good catalytic potency and reusability after reactivation. [ABSTRACT FROM AUTHOR]

[Display omitted] A structurally novel class of benzo- or pyrido-fused 1,3-dihydro-2 H -imidazole-2-imines was designed and evaluated in an inositol phosphate accumulation assay for G q signaling to measure agonistic activation of the orexin receptor type 2 (OX 2 R). These compounds were synthesized in 4–9 steps overall from readily available starting materials. Analogs that contain a stereogenic methyl or cyclopropyl substituent at the benzylic center, and a correctly configured alkyl ether, alkoxyalkyl ether, cyanoalkyl ether, or α-hydroxyacetamido substituted homobenzylic sidechain were identified as the most potent activators of OX 2 R coupled G q signaling. Our results also indicate that agonistic activity was stereospecific at both the benzylic and homobenzylic stereogenic centra. We identified methoxyethoxy-substituted pyrido-fused dihydroimidazolimine analog 63c containing a stereogenic benzylic methyl group was the most potent agonist, registering a respectable EC 50 of 339 nM and a maximal response (E max) of 96 % in this assay. In vivo pharmacokinetic analysis indicated good brain exposure for several analogs. Our combined results provide important information towards a structurally novel class of orexin receptor agonists distinct from current chemotypes. [ABSTRACT FROM AUTHOR]

In regulatory environmental monitoring programs, only a very small fraction of the vast number of per- and polyfluoroalkyl substances (PFAS) are investigated by target analysis. Therefore, non-target analysis (NTA) studies are increasingly conducted to detect unknown or unnoticed PFAS. These studies are often based on a few grab samples. Thus, discontinuously emitted PFAS from industrial batch processes might be easily overlooked. To address this deficiency and obtain in-depth information on the occurrence and temporal trend of PFAS in surface water impacted by treated industrial waste water, a comprehensive target and NTA study was implemented for 29 months. Elevated PFAS concentrations with up to 10.8 μg L−1 were detected in the river water by target analysis. In addition to PFAS target analysis, the water samples were analyzed by liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS). Data processing strategies and various filtering steps were applied to prioritize PFAS. Substances were identified by comparing data to available internal and external PFAS suspect lists, a fragment ion and neutral loss list, and spectral libraries. Several compounds were unequivocally identified based on reference standards. Fifty-five PFAS were (tentatively) identified using NTA. Of those, 43 could be assigned to 13 different homologous series. Partly fluorinated short-chain carboxylic acids (H-PFCA) and sulfonic acids (H-PFSA) were predominantly found in addition to perfluoroalkyl carboxylic acids (PFCA) and the alkyl ether carboxylic acid DONA. To the best of our knowledge, 12 PFAS were reported in surface water for the first time. Signal intensities of individual PFAS and signal ratios varied widely over time, which may indicate batch operations leading to discontinuous emission. Results and insights from this screening approach on PFAS can be used to optimize forthcoming surface water monitoring programs by including newly identified PFAS and selecting appropriate sampling intervals. [Display omitted] • Development of a monitoring strategy for known and unknown PFAS in highly impacted surface waters. • Non-target analysis (NTA) over a period of 29 months. • Novel data processing workflow for the identification and characterization of unknown PFAS. • Signal intensities and signal ratios of individual PFAS varied strongly over time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed catalyst CuAlO x and HZSM-5-Al 2 O 3 used for reductive etherification of furfural. • Excellent yield of 2-(isopropoxymethyl)furan was obtained in a flow reactor. • Si/Al ratio in HZSM-5 has a significant effect on catalyst performance. • The use of primary alcohols instead of 2-PrOH leads to a decrease in a yield. Furfuryl alkyl ethers (FAEs) are considered attractive biofuels or gasoline additives. Reductive etherification of bio-based furfural (FF) is a promising method for production of these compounds. In present work, we study the catalytic behavior of Cu-Al mixed oxide in combination with HZSM-5-Al 2 O 3 composites for the syntheses of FAEs in a flow reactor using H 2 as a reducing agent. The Cu-based catalyst ensures the hydrogenation of FF to furfuryl alcohol, which then reacted with alcohol in the presence of the acid catalyst. It was found that the reaction of FF with 2-propanol over catalytic system including HZSM-5(Si/Al = 40)-Al 2 O 3 leads to the formation of 2-(isopropoxymethyl)furan (IMF) in excellent yield due to the optimal concentration of strong Bronsted acid sites in the composite. Lower selectivity to IMF was observed in the presence of HZSM-5 with Si/Al ratio of 15, 25 and 140. In addition, the use of primary alcohols instead of 2-PrOH gives a significantly lower yield of FAEs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Torrefaction pretreatment and catalytic pyrolysis were employed to produce aromatics. • Torrefaction deoxygenation mechanism of lignin was established. • Oxygen was removed by the cleavage of ether alkyl bond and other oxygenated groups. • Incorporation of Nb metal on Al 2 O 3 could further improve the yield of aromatics. • Synergistic effect between the Nb modified Al 2 O 3 and the zeolite was established. Light aromatics are extremely important building blocks for manufacturing of numerous industrial products. The integrated approach of the torrefaction deoxygenation pretreatment (TDP) and the dual-catalyst catalytic fast pyrolysis (DC-CFP) using the HZSM-5 and metal (Nb, Zn, Ga, Ni, Ce) modified γ-Al 2 O 3 as catalyst was employed to enhance the production of light armatics from the hardwood lignin. The torrefaction deoxygenation mechanism was established based on the evolution of chemical structure of lignin. The maximum removal rate of oxygen element was 22.82%, achieved at the TDP temperature of 300 °C. The oxygen element was removed through the cleavage of β–O–4 bond, the aliphatic–OH and aliphatic–HC═O on the side-chain, and the aromatic–OH and aromatic–OCH 3 on the aromatic nucleus, releasing as the oxygenated gaseous compounds (CO 2 , H 2 O, and CO). The synergistic effect between HZSM-5 and metal modified γ-Al 2 O 3 in DC-CFP was observed, remarkably improving the yield of light aromatics. Metal modified γ-Al 2 O 3 aimed to first convert lignin into macromolecular phenols, and HZSM-5 was complementary used to convert the macromolecular phenols into light aromatics by the deoxygenation reactions. The maximum selective yield of bio-BTX were 74.39%, obtained at TDP temperature of 250 °C, lignin-to-catalyst ratio of 1:3, and HZSM-5-to-15%Nb/Al 2 O 3 of 2:2. [ABSTRACT FROM AUTHOR]

Alkoxylation and hydroxylation reactions of 1,5‐cyclooctadiene (cod) in an iridium complex with alcohols and water promoted by the reduction of oxygen to hydrogen peroxide are described. The exo configuration of the OH/OR groups in the products agrees with nucleophilic attack at the external face of the olefin as the key step. The reactions also require the presence of a coordinating protic acid (such as picolinic acid (Hpic)) and involve the participation of a cationic diolefin iridium(III) complex, [Ir(cod)(pic)2]+, which has been isolated. Independently, this cation is also involved in easy alkoxy group exchange reactions, which are very unusual for organic ethers. DFT studies on the mechanism of olefin alkoxylation mediated by oxygen show a low‐energy proton‐coupled electron‐transfer step connecting a superoxide–iridium(II) complex with hydroperoxide–iridium(III) intermediates, rather than peroxide complexes. Accordingly, a more complex reaction, with up to four different products, occurred upon reacting the diolefin–peroxide iridium(III) complex with Hpic. Moreover, such hydroperoxide intermediates are the origin of the regio‐ and stereoselectivity of the hydroxylation/alkoxylation reactions. If this protocol is applied to the diolefin–rhodium(I) complex [Rh(pic)(cod)], free alkyl ethers ORC8H11 (R=Me, Et) resulted, and the reaction is enantioselective if a chiral amino acid, such as l‐proline, is used instead of Hpic. [ABSTRACT FROM AUTHOR]

Mesoporous polyaromatic frameworks (PAF) based on tetraphenylmethane were synthesized. The PAF/AlCl3 and PAF/FeCl3 catalysts were prepared by impregnating the synthesized products with aluminum and iron chlorides, respectively. The resulting materials were characterized by low-temperature adsorption—desorption of nitrogen, IR spectroscopy, and transmission electron microscopy. The catalytic activity of PAF/AlCl3 and PAF/FeCl3 was tested in the phenol alkylation with oct-1-ene. The tests showed that the use of these catalysts gave both alkylphenols (C-alkylates) and alkyl phenyl ethers (O-alkylates) in the total yields up to 78 and 65% for PAF/AlCl3 and PAF/FeCl3, respectively. The fraction of alkylphenols depends on both the catalyst amount and reaction temperature. [ABSTRACT FROM AUTHOR]

Mammalian ATP-binding cassette (ABC) subfamily F member 3 (ABCF3) is a class 2 ABC protein that has previously been identified as a partner of the mouse flavivirus resistance protein 2',5'-oligoadenylate synthetase 1B (OAS1B). The functions and natural substrates of ABCF3 are not known. In this study, analysis of purified ABCF3 showed that it is an active ATPase, and binding analyses with a fluorescent ATP analog suggested unequal contributions by the two nucleotide-binding domains. We further showed that ABCF3 activity is increased by lipids, including sphingosine, sphingomyelin, platelet-activating factor, and lysophosphatidylcholine. However, cholesterol inhibited ABCF3 activity, whereas alkyl ether lipids either inhibited or resulted in a biphasic response, suggesting small changes in lipid structure differentially affect ABCF3 activity. Point mutations in the two nucleotide-binding domains of ABCF3 affected sphingosine-stimulated ATPase activity differently, further supporting different roles for the two catalytic pockets. We propose a model in which pocket 1 is the site of basal catalysis, whereas pocket 2 engages in ligand-stimulated ATP hydrolysis. Co-localization of the ABCF3-OAS1B complex to the virus-remodeled endoplasmic reticulum membrane has been shown before. We also noted that co-expression of ABCF3 and OAS1B in bacteria alleviated growth inhibition caused by expression of OAS1B alone, and ABCF3 significantly enhanced OAS1B levels, indirectly showing interaction between these two proteins in bacterial cells. As viral RNA synthesis requires large amounts of ATP, we conclude that lipid-stimulated ATP hydrolysis may contribute to the reduction in viral RNA production characteristic of the flavivirus resistance phenotype. [ABSTRACT FROM AUTHOR]

The catalyst structure–property relationships of the phenoxyimine complexes in controlled cationic polymerization of vinyl ethers were investigated based on the Hammett correlation. The correlation analyses of a series of experiments using the phenoxyimine ligands/TiCl4 initiating systems indicated that the substituents on the N‐aryl phenoxyimine ligands affected the polymerization rate and stereoselectivity. Importantly, a linear correlation was observed between the Hammett substituent constants and the polymerization rates, which indicates that the Lewis acidity of the complex is affected by the electron‐withdrawing and ‐donating effects of the substituents. The tacticity of product polymers correlated to the Hammett substituent constants. Unlike the relationship with the polymerization rates, the σ– values, which account for the enhanced resonance effects, were more appropriate for the relationship with the tacticity than the normal σ values. In contrast, the polymerization behavior using o‐substituted ligands exhibited a trend different from those using p‐ or m‐substituted ligands. The structural change, which was caused by the rotation of the CN bonding, most likely triggered the acceleration effect in the case of the o‐substituents. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2021–2029 [ABSTRACT FROM AUTHOR]

In this work, we investigated the activity of Keggin heteropolyacid catalysts (i.e., H3PW12O40, H3PMo12O40 and H4SiW12O40) in β-pinene reactions with alkyl alcohols (i.e. methyl, ethyl, propyl, sec-propyl, butyl and sec-butyl alcohols), and exploring the different aspects that drive the selectivity of this process. We have found that carbon skeletal rearrangements and isomerization providing intermediate carbocations that controlling the reaction selectivity. β-pinene was preferentially converted to α-terpinyl ion which undergoes a nucleophilic attack of alcohol providing alkyl alcohol. Bornyl ion was converted to bornyl and fenchyl ethers. The other secondary products were β-pinene isomers obtained from bornyl and α-terpinyl carbocations. Phosphotungstic acid (i.e., H3PW12O40) was the most active catalyst and selective toward the main product (α-terpinyl alkyl ether); the highest conversion (ca. 96%) and ether selectivity (ca. 61%) was achieved in the reactions with β-pinene. Although having also been alkoxylate, α-pinene was less reactive (ca. 40%), while camphene and limonene remained unreactive under reaction conditions studied. An increase of temperature resulted in an improvement on conversion of β-pinene and selectivity toward α-terpinyl methyl ether. Similarly, the H3PW12O40 concentration played a crucial role on reaction selectivity. This work presents positive features such as a short reaction time, high atom economy, mild reaction conditions (i.e., low temperature and room pressure). Even though soluble the catalyst was easily recovered by liquid -liquid extraction and efficiently reused. [ABSTRACT FROM AUTHOR]

A transition-metal-free etherification protocol that is capable of synthesizing deuterated ethers is described. A wide range of aryl alkyl ethers and thioethers were suitable for this transformation owing to the mild reaction conditions. Besides, a series of sterically bulky deuterated alcohols were successfully incorporated into cyano-substituted arenes. The results of mechanistic studies suggested this reaction might take place via nucleophilic aromatic substitution pathway. [ABSTRACT FROM AUTHOR]

Furans constitute an important class of aromatic heterocycles displaying a wide range of pharmacological activities.[[1]] In addition, furans are the chief motifs of many natural products.[[7]] Furans are used as flavor and fragrance compounds as well. A mild gold catalyzed cascade reaction of cyclopropanes derived from enones led to the synthesis of highly substituted furans ( I Scheme 17 i ).[63] Mechanistically furan formation takes place through the attack of a carbonyl oxygen lone pair on the alkyne followed by rearrangement. Early on, D'yakonov and Komendantov used this strategy to obtain 2-alkoxy furans using Cu(II) species.[[82]] Later, numerous research groups expanded this reaction by using different transition metal catalysts for the efficient synthesis of furan molecules. The Ph SB 3 sb PO produced by the Wittig reaction of phosphorane B 146 b and 1,2-dicarbonyl compound B 147 b is used to catalyze the 1,4-reduction of enone intermediate in the presence of HSiCl SB 3 sb and the waste HCl thus generated promotes the cyclization reaction to yield the final furan product ( I Scheme 51 i ).[113] The appearance of so many new papers on furan synthesis periodically is a testimony to the importance and relevance of the heterocycle.[[138]] This review highlights a variety of synthetic methodologies adopted for furan synthesis and focuses on the literature from 2005 onwards. [Extracted from the article]

Surfactant systems incorporating wormlike micelles (WLM) are utilized in both industrial and consumer products. While the viscoelastic behavior of such systems provides for many desired end‐use properties, there is often a need to further modify the rheological properties of such systems. These WLM systems behave much like polymer systems. Furthermore, incorporation of nanosized particles results in interaction of nanoparticles with the large WLM structures altering the rheological behavior. While there are a number of studies that have focused on the effect of particles on the rheological behavior in cationic surfactant systems, fewer studies have been done on systems containing anionic surfactants. In this study, relaxation behaviors in systems containing sodium alkyl ether sulfate and sodium carbonate were studied. The anionic surfactant was an alkyl ether sulfate with an average chain length of 12 carbons and one ethoxy group. WLM behavior was achieved through the addition of sodium carbonate. Ludox TMA, a nanosized colloidal silica, was employed at different concentrations in the WLM systems. Temperature was varied between 5 and 45°C. While characterization of relaxation in terms of the Maxwell model adequately described data below the threshold of ωτ ~1, the model failed to adequately describe behavior at higher frequencies. A modified expression with an additional relaxation mode adequately described relaxation throughout the frequency range studied. It was also found that zero‐shear viscosities generally increased with an increase in silica concentration, and relaxation times decreased. Measurements of relaxation due to a compressive stress via ultrasonic attenuation measurements in the surfactant/particle systems are also discussed. [ABSTRACT FROM AUTHOR]

To explore the effects of methane on the characteristics of coal spontaneous combustion, coal low-temperature oxidation and Fourier transform infrared spectroscopy experiments were conducted. The tested airflows had an oxygen–nitrogen ratio of 0.266, and methane concentrations of 0−3% by volume. Moreover, the coal oxidation characteristics and the various types and quantities of functional groups were investigated. The results show that CO/CO2 production and oxygen consumption rates were higher for coal samples under airflow atmospheres containing methane than for airflow atmospheres without methane. However, the apparent activation energy of coal samples in airflows containing methane was lower than for airflow atmosphere without methane. It is speculated that airflows with 1−3% methane concentrations have a positive impact on coal spontaneous combustion. This study used OMNIC and PeakFit v4.12 programs to analyze the effect of airflows containing methane on the functional groups of coal spontaneous combustion. The Pearson correlation coefficient method was introduced to analyze the relationship between the key functional groups and apparent activation energies of coal samples. The results indicated that the key functional groups of the coal samples below the critical temperature were methyl (−CH3) and methylene (−CH2). Above the critical temperature, aromatic C−H, methyl (−CH3), and methylene (−CH2) were the key functional groups. After reaching the cracking temperature, aromatic C−H and alkyl ether C−O−C became the key functional groups. With increasing methane concentration, aromatic C–H makes a negative contribution to coal spontaneous combustion, while methyl (−CH3) and methylene (−CH2) make positive contributions. The inhibition of alkyl ether C−O−C to coal spontaneous combustion is weakened, and the inhibition of aromatic ring C=C to coal spontaneous combustion is enhanced. [ABSTRACT FROM AUTHOR]

Owing to their wide occurrence in nature and immense applications in various fields, the synthesis of aryl alkyl ethers has remained a focus of interest. In contrast to the conventional/traditional methods of etherification, herein, we have reported a more efficient method, which is better yielding and more general in application. The etherification of aryl halides by alkoxy/phenoxy silanes was catalyzed by copper acetate in the presence of cesium carbonate and oxygen in DMF at 145 °C. All the as-synthesized compounds were characterized via the 1H-NMR and 13C-NMR spectroscopic techniques. Density functional theory calculations using the B3LYP functional were performed to elucidate the reaction mechanism. The C–O coupling reaction between 2-nitroiodobenzene and tetramethoxysilane was used as a model reaction. The activation energy barriers for the generation of catalytic species (31.6 kcal mol−1) and the σ-bond metathesis (16.0 kcal mol−1), oxidative addition/reductive elimination (20.3 kcal mol−1), halogen atom transfer (19.2 kcal mol−1) and single electron transfer (SET) (29.5 kcal mol−1) mechanisms for the C–O coupling reaction were calculated. Calculations for the key reaction steps were repeated with the B3PW91, PBEH1PBE, wB97XD, CAM-B3LYP and mPW1LYP functionals. The formation of catalytic species via a single electron transfer reaction between tetramethoxysilane and copper acetate, formation of methoxy radicals and methoxylation of copper showed an overall energy barrier of 31.6 kcal mol−1, and therefore is the rate determining step. [ABSTRACT FROM AUTHOR]

Diallyltriazinedione‐type acid‐catalyzed alkylating agents (ATTACKs‐R) with 10 different alkyl groups (R), including benzyl, substituted benzyl, allyl, and methyl groups were synthesized. The palladium‐catalyzed intramolecular O‐to‐N allylic rearrangement of 2,4‐bis(allyloxy)‐6‐chloro‐1,3,5‐triazine was developed to introduce various alkoxy groups into the N,N′‐dialkylated triazinedione skeleton. O‐Alkylation of alcohols with ATTACKs‐R was carried out in 1,4‐dioxane in the presence of 2,6‐di‐tert‐butylpyridinium trifluoromethanesulfonate or trifluoromethanesulfonic acid as a catalyst. Six selected ATTACKs‐R bearing benzylic R groups were employed to prepare alkyl ethers from primary, secondary, and tertiary alcohols. The reactions of ATTACKs‐R bearing an o‐nitro‐substituted benzyl group tended to afford low yields. Comparison of four different triazinedione‐based benzylating reagents suggested that the N,N′‐substituents affected the reactivity. [ABSTRACT FROM AUTHOR]

A facile and practical approach for the difluoromethylation of aliphatic alcohols with an S-(difluoromethyl)sulfonium salt was developed. A wide variety of alcohols with broad functional groups are compatible to furnish the corresponding alkyl difluoromethyl ethers in good to excellent yields under mild reaction conditions. Control experiments and DFT computational studies suggest that the difluoromethylation of alcohols mainly proceeds via a difluorocarbene pathway involving a five-membered transition state with the participation of water, whose crucial role in this reaction was also elucidated by control experiments. [ABSTRACT FROM AUTHOR]

Highlights from the article: Other possible approaches to solve the problem of HMF decomposition are obtaining HMF in highly pure crystalline form, using stabilizing additives, and synthesizing stable HMF derivatives in situ without the isolation of unstable HMF as an intermediate. The low chemical stability of HMF is a fundamental limitation that complicates both the synthesis and modification of HMF. With high probability, the usage of new chemical building blocks instead of fossil-derived base and commodity chemicals will lead to a rethinking of the utilization of many existing essential and valuable products (drugs, agrochemicals, materials, etc.) because their preparation from other (biobased) substrates will require new research and industrial efforts. In contrast, the move towards awakening of the sleeping giant associated with HMF-promoted drop-in biorefining, the formation of a reliable and competitive "chemical bridge" between HMF and most of the important basic petrochemical aromatic building blocks and related commodity chemicals appears to be one of the key missing links (Figure d).

We describe the synthesis, characterization and direct‐write 3D printing of triblock copolymer hydrogels that have a tunable response to temperature and shear stress. In aqueous solutions, these polymers utilize the temperature‐dependent self‐association of poly(alkyl glycidyl ether) 'A' blocks and a central poly(ethylene oxide) segment to create a physically crosslinked three‐dimensional network. The temperature response of these hydrogels was dependent upon composition, chain length and concentration of the 'A' block in the copolymer. Rheological experiments confirmed the existence of sol–gel transitions and the shear‐thinning behavior of the hydrogels. The temperature‐ and shear‐responsive properties enabled direct‐write 3D printing of complex objects with high fidelity. Hydrogel cytocompatibility was also confirmed by incorporating HeLa cells into select hydrogels resulting in high viabilities over 24 h. The tunable temperature response and innate shear‐thinning properties of these hydrogels, coupled with encouraging cell viability results, present an attractive opportunity for additive manufacturing and tissue engineering applications. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The development of new surfactants with interesting properties and new functionalities that can be controlled in a simple manner is an important industrial objective. Herein, we report the synthesis of homogeneous polyoxyethylene (EO) alkyl ether nonionic surfactants modified with alkoxy groups (C 12 EO 8 OR, where C 12 and EO 8 are dodecyl and octaoxyethylene chains, respectively, and R = Me and Et) from a homogeneous EO-type hexaoxyethylene dodecyl ether (C 12 EO 6) and diethylene glycol monomethyl ether or diethylene glycol monoethyl ether. The adsorption and aggregation properties of these surfactants were characterized through cloud point and surface tension measurements, and by small-angle X-ray scattering, polarization microscopy, and cryogenic transmission electron microscopy; these properties were compared to those of previously reported homogeneous EO-type (C 12 EO 8) and polyoxypropylene-polyoxyethylene type surfactants (C 12 EO 8 PO y , y = 1, 2, 3). The introduction of a methoxy or ethoxy group at the terminus of the EO chain in C 12 EO 8 resulted in an increase in hydrophobicity and a greatly reduced cloud point. Substitution of the terminal hydroxy group of the EO chain in C 12 EO 8 with methoxy and then ethoxy led to increasingly lower surface tensions in solution and more efficient air/water interfacial adsorption. C 12 EO 8 OR formed small micelles at low concentrations in solution, and the micelles of C 12 EO 8 OMe transformed to hexagonal liquid crystals with increasing surfactant concentration, whereas C 12 EO 8 OEt remained to form micelles even at high concentration; that is, the introduction of bulkier functional groups into the C 12 EO 8 surfactant helps to control the formation of aggregates with higher-order structures. Unlabelled Image • Homogeneous EO type surfactants modified with alkoxy groups were synthesized. • The introduction of a methoxy or ethoxy group reduces the cloud point. • C 12 EO 8 OR have more efficient air/water interfacial adsorption compared with C 12 EO 8. • C 12 EO 8 OR can control the formation of aggregates with higher-order structures. [ABSTRACT FROM AUTHOR]

Highlights • Novel approach for enhancing the CO 2 absorption using membrane contactors. • Packing the solvent side of the membrane contactors with glass beads. • Fabrication of membrane contactors with transparent acrylic material. • Mass transfer coefficient results agreed well with those of the experimental data. Abstract The efficiency of gas removal using hollow fiber membrane (HFM) contactors and liquid solvents is determined by several factors. The liquid film resistance has been identified as one of the important factors affecting the overall mass transfer coefficient. The present work describes the use of spherical glass beads as additional packing in the shell (solvent) side to act as solid baffles which should impart stirring effect in the flowing solvent and increase its velocity. These two effects should decrease the liquid film resistance and consequently enhance the gas removal efficiency. Two types of custom-made hollow fiber membrane contactors (HFMC) were constructed from thick-walled acrylic tube (20 mm ID, OD 30 mm) and equipped with the commercially available poly(tetrafluoroethylene-co-perfluorinated alkyl vinyl ether) (PFA) hollow fibers. In one type of the contactors, glass beads were introduced in the shell side. The two types of contactors (with and without beads) were tested and compared in terms of CO 2 removal efficiency from gas mixtures (5% CO 2 − 95% CH 4) using aqueous sodium hydroxide and several amine solutions. Different parameters were studied to evaluate the performance of the membrane contactors at feed gas pressures up to 25 bars. The obtained results indicated an increase of up to 21% enhancement in CO 2 removal efficiency when the shell compartment was packed with the glass beads. The results obtained from the overall mass transfer coefficient model showed good agreement with those of the experimental data. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The emulsification, solubilization and detergency depend on the EO chain lengths and the presence or absence of PO chains. • The introduction of a PO chain into EO surfactant lowers the emulsion stability. • The high solubilization ability is found in C 12 EO 6 PO 3 for naphthalene and C 12 EO 8 PO 3 for stearic acid. • The removal of stearic acid from a gold substrate is the highest for C 12 EO 6 PO 3. Abstract The emulsification and solubilization properties and detergency behaviors were investigated using homogeneous polyoxypropylene-polyoxyethylene (PO-EO) alkyl ether type nonionic surfactants (C 12 EO x PO 3 , where x represents EO chain lengths of 6 and 8, and C 12 and PO 3 indicate the dodecyl chain and single trioxypropylene chain, respectively) and polyoxyethylene (EO) alkyl ether type nonionic surfactants (C 12 EO x , x = 6 and 8). These nonionic surfactants possess single EO and PO chain lengths without a distribution. An oil-in-water (O/W) type emulsion prepared using mixtures of nonionic surfactant C 12 EO x PO 3 or C 12 EO x solutions and squalane was shown to be stable in the order of C 12 EO 6 PO 3 << C 12 EO 6 < C 12 EO 8 PO 3 < C 12 EO 8. The introduction of a PO chain to the terminal hydroxy group of the EO chain lowers the emulsion stability owing to the difficult orientation of a complex structure such as the hydrophobic alkyl chain–hydrophilic EO chain-hydrophobic PO chain at the water/oil interface. The solubilization of these nonionic surfactants was shown to be higher for stearic acid than for naphthalene as a solubilizate. The molar solubilization ratio (MSR) for naphthalene and stearic acid was the highest for C 12 EO 6 PO 3 and C 12 EO 8 PO 3 , respectively. The removal of stearic acid from a gold substrate evaluated using a quartz crystal microbalance (detergency) was the highest for C 12 EO 6 PO 3 among the four surfactants applied. Thus, no significant correlation was found among the emulsification, solubilization, and detergency behaviors ; however, a high performance for each objective was obtained by controlling both the EO chain length and the introduction of a PO chain. [ABSTRACT FROM AUTHOR]

Abstract Practical preparations of dichloromethyl alkyl ethers are described, based on the reaction of alkyl formates with oxalyl chloride in the presence of N -methylformanilide. The method involves a simple procedure that does not require the use of harmful reagents. Dichloromethyl propyl and dichloromethyl butyl ethers represent secure synthetic equivalents to dichloromethyl methyl ether. Formylations of both electron-deficient and electron-rich aromatics with these dichloromethyl alkyl ethers in the presence of AlCl 3 , FeCl 3 , or TiCl 4 have been systematically investigated. A plausible mechanism of formylation is discussed. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Jocic-type protocol for the construction of the pyrrolonaphthoxazepine (PNOX) core. • A variety of reaction conditions were investigated. • The novel route significantly improved overall yields to obtain PNOX-based compounds. • The novel route was extended to the preparation of 1,4-benzoxazinone templates. Abstract We developed a Jocic-type protocol for the construction of the pyrrolonaphthoxazepine (PNOX) core. After an initial investigation based on the isolation of a trichloromethyl carbinol derivative, we shifted our attention towards a multicomponent single-step protocol. Screening of a variety of bases and solvents led to the identification of the optimum conditions for the preparation of the key α-aryloxy carboxylic acids to undergo intramolecular cyclization. The novel chemical route significantly improved overall yields for the preparation of PNOX-based compounds and was successfully extended to the preparation of 1,4-benzoxazinone-based templates. [ABSTRACT FROM AUTHOR]

Polymers and surfactants are increasingly applied to improve the cold flow properties of diesel fuel. However, their depressive effects are closely related to the molecular structure of the structuring units. In this study, the structural properties of surfactants were applied to synthesise a series of polymers consisting of tetradecyl methacrylate and ether compounds as structural units, with the long alkyl chain and ether compounds acting as hydrophobic and hydrophilic groups, respectively. The polymers consisting of tetradecyl methacrylate and ether compounds combined the advantages of polymers and surfactants in improving the cold flow properties of diesel. Besides, the effects of different functional groups, molar ratios and additive amounts on the improvement of diesel fuel low–temperature fluidity were investigated. The results indicated that 1500 ppm polymer with tetradecyl methacrylate and allyl glycidyl ether as structural monomers at a molar ratio of 6:1 as polymer pour point depressant (PPD) showed a greater enhancement of cold filter plugging point and solid point of diesel (ΔCFPP = 12 ℃, ΔSP = 17 ℃). The molecular structures of efficient pour point depressants were screened and the polymer composition was broadened. Finally, differential scanning calorimeter, rheological and polarising optical microscopy were used to analyse the changes in wax crystals size and morphology in pure diesel and diesel treated with polymer PPDs, and a mechanism for polymer PPDs with surfactant structural properties to change the crystallisation and aggregation behaviour of wax crystals was inferred. [Display omitted] [ABSTRACT FROM AUTHOR]

Searching for renewable alternatives for fossil carbon resources to produce chemicals, fuels and materials is essential for the development of a sustainable society. Lignin, a major component of lignocellulosic biomass, is an abundant renewable source of aromatics and is currently underutilized as it is often burned as an undesired side stream in the production of paper and bioethanol. This lignin harbors great potential as source of high value aromatic chemicals and materials. Biorefinery schemes focused on lignin are currently under development with aim of acquiring added value from lignin. However, the performance of these novel lignin-focused biorefineries is closely linked with the quality of extracted lignin in terms of the level of degradation and modification. Thus, the reactivity including the degradation pathways of the native lignin contained in the plant material needs to be understood in detail to potentially achieve higher value from lignin. Undegraded native-like lignin with an as close as possible structure to native lignin contained in the lignocellulosic plant material serves as a promising model lignin to support detailed studies on the structure and reactivity of native lignin, yielding key understanding for the development of lignin-focused biorefineries. The aim of this review is to highlight the different methods to attain "native-like" lignins that can be valuable for such studies. This is done by giving a basic introduction on what is known about the native lignin structure and the techniques and methods used to analyze it followed by an overview of the fractionation and isolation methods to isolate native-like lignin. Finally, a perspective on the isolation and use of native-like lignin is provided, showing the great potential that this type of lignin brings for understanding the effect of different biomass treatments on the native lignin structure. • Collection of methods involving the isolation of lignin with a native-like structure; • Retention of the alkyl aryl ether linking motif is used as the key benchmark. • Balance between lignin quality and intensity of the isolation is of significance. • Guidelines for method selection to isolate native-like lignin are provided. [ABSTRACT FROM AUTHOR]

• Aryl trifluorovinylethers were used as precursors for preparing a diverse pool of hydro-/vinylfluoroethers. • Hydro-/vinylfluoroethers were prepared in a facile base-promoted addition using heteronucleophiles. • Regioselectivity of generated vinylfluoroethers was dependent on heteroatom of the nucleophile as demonstrated by nine examples. • Versatile synthetic methodology of this new class of fluorinated ethers synthesis should garner interest as useful intermediates for a multitude of materials applications. The nature of the structural configuration of fluorinated ethers has been widespread as a crucial component for improving high performance polymers, industrial agrochemicals, and targets for important pharmaceutical drugs. This is a result of countless advances in organo-fluorine methodologies with this unique substructure in order to overcome many traditional synthetic challenges. In this work, we expand on the preparation of fluorinated ethers by introducing hetero-nucleophiles to a highly electrophilic aryl trifluorovinyl ether affording a new class of difunctional aryl/alkyl fluorinated ethers that would serve as useful intermediates. The facile reaction chemistry of various nucleophile substrates, effect of base concerning regio-selectivity, and structural elucidation trends of the synthesized aryl/alkyl fluoroethers will be discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Alkoxyiodination of alkyl allyl ethers with elemental iodine in allyl and propargyl alcohols in the presence of clinoptilolite [(NaK)4CaAl6Si30O72] gave the corresponding alkyl 2-(allyloxy or propargyloxy)-3-iodopropyl ethers in high yields. [ABSTRACT FROM AUTHOR]

Reported herein is a novel photoredox‐catalyzed approach for ether synthesis and it involves alkoxyl radicals generated from N‐alkoxypyridinium salts. A wide range of alkenes are smoothly difunctionalized in an anti‐Markovnikov fashion, affording various functionalized alkyl alkyl ethers. Notably, this mild process tolerates a number of functional groups and is efficiently carried out under both batch and flow conditions. Importantly, electron paramagnetic resonance (EPR) experiments by spin trapping were carried out to characterize the radical intermediates involved in this radical/cationic process. [ABSTRACT FROM AUTHOR]

Abstract: Alkyl aryl ethers are an important class of compounds in medicinal and agricultural chemistry. Catalytic C(sp3)−O cross‐coupling of alkyl electrophiles with phenols is an unexplored disconnection strategy to the synthesis of alkyl aryl ethers, with the potential to overcome some of the major limitations of existing methods such as C(sp2)−O cross‐coupling and SN2 reactions. Reported here is a tandem photoredox and copper catalysis to achieve decarboxylative C(sp3)−O coupling of alkyl N‐hydroxyphthalimide (NHPI) esters with phenols under mild reaction conditions. This method was used to synthesize a diverse set of alkyl aryl ethers using readily available alkyl carboxylic acids, including many natural products and drug molecules. Complementarity in scope and functional‐group tolerance to existing methods was demonstrated. [ABSTRACT FROM AUTHOR]

We previously showed that an alkyl-ether analog of lysophosphatidic acid, AGP (alkyl-glycerophosphate), accumulates in human atherosclerotic plaques and is a potent agonist of peroxisome proliferator-activated receptor-gamma (PPARγ). On the other hand, cyclic phosphatidic acid (cPA), similar in structure to AGP, can negatively regulate PPARγ. However, in this study, cPA had no effect on the expression and secretion of C-C motif chemokine 2 (CCL-2), a chemokine that is also linked to inflammatory responses and atherosclerosis. We showed that AGP enhances CCL-2 mRNA expression and secretion in a dose-dependent manner. Furthermore, oxidative stress plays a major role in the pathology of cardiovascular diseases; we showed that AGP triggers ROS generation and lipid peroxidation and that ROS and 8-isoprostane generation can be suppressed by a PPARγ antagonist. These results suggest that an imbalance of the PPARγ agonist-antagonist equilibrium is involved in changes in cellular functions, including ROS generation and lipid peroxidation. [ABSTRACT FROM AUTHOR]

Great progress has been made in reverse flotation of fine quartz, especially many new reagents were proved their excellent effects. However, the influences of complex flotation system on fine quartz flotation still need to be scrutinized. In this study, alkyl ether amine (Flotigam EDA-C from Clariant) was used as a collector for the flotation of quartz. It shows better collectability for the flotation of quartz at about pH 10.0 (±0.2). The adsorption mechanism of EDA-C on quartz and the influence of calcium ions on the flotation of quartz were investigated by adsorption tests, zeta-potential measurements, FTIR spectra measurements, X-ray photoelectron spectroscopic and atomic force microscopy imaging. Results show that EDA-C adsorbs on the quartz surface in physical adsorption with no new products, changing its zeta potentials and increasing its hydrophobicity. Calcium ion concentration of 20 mg/L, 40 mg/L, 60 mg/L and 1 g/L can inhibit the quartz surface strongly and decrease its recovery sharply. Inhibition action of 2 g/L Ca 2+ decreased, even disappeared when the collector concentration increased to 90 mg/L. Calcium ions changed the chemical environment of Si atoms and O1s on the quartz surface. After positively charged CaOH + adsorbed on quartz surface, the amount of EDA-C adsorbed on quartz surface and the recovery decreased. It was greatly inspired to explore quartz separation application from these results. [ABSTRACT FROM AUTHOR]

Chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) caused great concerns recently as novel fluorinated alternatives. However, information on their bioconcentration, bioaccumulation and biomagnification in marine ecosystems is limited. In this study, 152 biological samples including invertebrates, fishes, seabirds and mammals collected from Bohai Sea of China were analyzed to investigate the residual level, spatial distribution, bioaccumulation and biomagnification of Cl-PFESAs. 6:2 Cl-PFESA was found in concentrations ranging from