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A route is developed to (γ,γ',γ"'‐trifluoro)neopentyl (TFNP) aryl ethers to extend the methods for the introduction of the tert‐butyl group, carrying a fluorine on each of the methyl substituents. The route combines neopentyltosylate 3 with phenols and thiophenols to give efficient substitution reactions to the corresponding TFNP aryl ethers. The three C−F bonds adopt a helical propeller conformation as revealed by computation and single crystal X‐ray structure analysis. The LogPs of TFNP ethers are lower (more hydrophilic) than their neopentyl analogues. The metabolism of selected TFNP ethers was explored in the fungus Cunninghamella elegans. [ABSTRACT FROM AUTHOR]

A Pd‐catalyzed carbonylative Heck reaction of 2‐iodophenyl alkenyl ether using Mo(CO)6 as a safe CO source has been developed. This research provides an atom‐economic and straightforward route for the efficient construction of benzofuran‐3(2H)‐one scaffolds with a C2 quaternary center in moderate to good yields, which features operational safety, good functional group compatibility and easy scale‐up. [ABSTRACT FROM AUTHOR]

Although ethers are common in secondary natural products, they are an underrepresented functional group in primary metabolism. As such, there are comparably few enzymes capable of constructing ether bonds in a general fashion. However, such enzymes are highly sought after for synthetic applications as they typically operate with higher regioselectivity and under milder conditions than traditional organochemical approaches. To expand the repertoire of well characterized ether synthases, we herein report on a promiscuous archaeal prenyltransferase from the scarcely researched family of geranylgeranylglyceryl phosphate synthases (GGGPSs or G3PSs). We show that the ultrastable Archaeoglobus fulgidus G3PS makes various (E)‐ and (Z)‐configured prenyl glycerol ethers from the corresponding pyrophosphates while exerting perfect control over the configuration at the glycerol unit. Based on experimental and computational data, we propose a mechanism for this enzyme which involves an intermediary prenyl carbocation equivalent. As such, this study provides the fundamental understanding and methods to introduce G3PSs into the biocatalytic alkylation toolbox. [ABSTRACT FROM AUTHOR]

The photoinduced regioselective HAT reactions of acetals, ethers, and alcohols using benzoic acids in a two‐molecule photoredox system led to the formation of new C−C bonds with alkenes under mild conditions. Aryl carboxy radicals generated from benzoic acids in a two‐molecule photoredox system can function as catalytic HAT reagents, even though an excess amount of a hydrogen donor substrate is required. Various acetals, ethers, alcohols, and alkenes can be employed in the photoreaction to provide both high yields of adducts and high recoveries of benzoic acids. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Key Scientists Electron‐rich alkynes, such as ynol and thioynol ethers, have proven to be versatile and appealing partners in catalytic cycloaddition reactions, and thus have raised considerable attentions owing to the practical application in the modular assembly of valuable carbo‐ and heterocycles. The past decades have witnessed inspiring advances in this emerging field, and an increasing number of related discoveries have been exploited. Divided into two main sections on the basis of substrate type, in each section this comprehensive review will initially summarize their synthetic preparations and subsequently examine their reactivity in every sort of catalytic cycloaddition with emphasis on the methodology development, aimed at providing an access to this burgeoning area and encouraging further innovations in the near future. For the cycloaddition of ynol ethers, in 2004, Kozmin et al. firstly developed a silver‐catalyzed [2 + 2] cycloaddition of siloxy alkynes with electron‐poor olefins. In 2012, Hiyama et al. realized a palladium‐catalyzed formal [4 + 2] annulation of alkynyl aryl ethers with internal alkynes. In the same year, Sun et al. discovered an efficient [6 + 2] cyclization between siloxy alkynes and 2‐(oxetan‐3‐yl)benzaldehydes by applying HNTf2 as catalyst. In 2017, Wender et al. first utilized vinylcyclopropanes (VCPs) as coupling partners in the [5 + 2] annulation of ynol ethers. In 2018 and 2020, Ye et al. reported zinc‐catalyzed formal [3 + 2] and [4 + 3] cycloaddition, respectively. For the cycloaddition of thioynol ethers, in 2004, Hilt et al. realized a [4 + 2] cycloaddition by employing the alkynyl sulfides and acyclic 1,3‐dienes. In 2006, a ruthenium‐catalyzed [2 + 2] cycloaddition of thioynol ethers with bicyclic alkenes was accomplished by Tam. In 2014, Sun et al. reported an elegant iridium‐catalyzed click reaction of thioalkynes with azides. [ABSTRACT FROM AUTHOR]

We disclose a benzylic C−H oxidative coupling reaction with alcohols that proceeds through a synergistic deprotonation, halogenation and substitution sequence. The combination of tert‐butoxide bases with 2‐halothiophene halogen oxidants enables the first general protocol for generating and using benzyl halides through a deprotonative pathway. In contrast to existing radical‐based methods for C−H functionalization, this process is guided by C−H acidity trends. This gives rise to new synthetic capabilities, including the ability to functionalize diverse methyl(hetero)arenes, tolerance of oxidizable and nucleophilic functional groups, precision site‐selectivity for polyalkylarenes and use of a double C−H etherification process to controllably oxidize methylarenes to benzaldehydes. [ABSTRACT FROM AUTHOR]

Axially chiral diaryl ethers represent a distinct class of atropisomers, characterized by a unique dual C─O axes system, which have been found in a variety of natural products, pharmaceuticals, and ligands. However, the catalytic enantioselective synthesis of these atropoisomers poses significant challenges, due to the difficulty in controlling both chiral C─O axes, and their more flexible conformations. Herein, an efficient protocol for catalytic enantioselective synthesis of axially chiral diaryl ethers is presented using organocatalyzed asymmetric Povarov reaction‐enabled desymmetrization, followed by aromatizations. This method yields a wide range of novel quinoline‐based diaryl ether atropoisomers in good yields and high enantioselectivities. Notably, various aromatization protocols are developed, resulting in a diverse set of polysubstituted quinoline‐containing diaryl ether atropisomers. Thermal racemization studies suggested excellent configurational stabilities for these novel diaryl ether atropisomers (with racemization barriers up to 38.1 kcal mol−1). Moreover, this research demonstrates for the first time that diaryl ether atropisomers lacking the bulky t‐Bu group can still maintain a stable configuration, challenging the prior knowledge in the field. The fruitful derivatizations of the functional group‐rich chiral products further underscore the value of this method. [ABSTRACT FROM AUTHOR]

Comprehensive Summary The difunctionalization of bicyclo[1.1.0]butanes is an under‐explored transformation that accesses to moieties that are otherwise difficult to prepare. Herein, a new oxidative radical alkylarylation of N‐aryl bicyclobutyl amides with C(sp3)−H feedstocks is achieved in an atom‐economic and photocatalyst‐ and light‐free manner. This protocol follows a sequential C(sp3)–H/C(sp2)–H functionalization, providing an efficient route for diversity‐oriented synthesis of functionalized 3‐spirocyclobutyl oxindoles. In particular, a wide range of C(sp3)−H feedstocks, including ether, alcohol, amine, thioether, polychlorinated methane, silane, acetone, acetonitrile, toluene, and alkane are all suitable for the C(sp3)−H functionalization, demonstrating the broad applicability of this transformation. [ABSTRACT FROM AUTHOR]

A six‐cyclic crown ether‐type pillar[5]arene was synthesized, and the five ethylene oxide loops were located outside the cavity and not affected by temperature changes which was confirmed by variable‐temperature NMR experiment in DMSO‐d6 and CDCl3 and 2D 1H−1H NOESY experiment in CDCl3. The six‐cyclic pillar[5]‐crown also showed greater binding ability of host‐guest with bis(pyridinium) derivatives than conventional alkoxy pillar[5]arenes that illustrated through 1H NMR titration spectroscopic experiment in acetone‐d6/CDCl3 (1 : 1) and UV‐vis titration experiments in CHCl3 at room temperature. The five benzocrown ethers at the periphery were able to bind metal cations by 1H NMR titration spectroscopic experiment in CD2Cl2/methanol‐d4(9 : 1). [ABSTRACT FROM AUTHOR]

The first aerobic protocol of direct transformation of p‐methoxybenzyl (PMB) ethers to carboxylic acids efficiently with Fe(NO3)3 ⋅ 9H2O and TEMPO as catalysts at room temperature has been developed. The reaction accommodates C−Br bond, terminal/non‐terminal C−C triple bond, amide, cyano, nitro, ester, and trifluoromethyl groups. Even highly selective oxidative deprotection of different benzylic PMB ethers has been realized. The reaction has been successfully applied to the total synthesis of natural product, (R)‐6‐hydroxy‐7,9‐octadecadiynoic acid, demonstrating the practicality of the method. Based on experimental studies, a possible mechanism involving oxygen‐stabilized benzylic cation has been proposed. [ABSTRACT FROM AUTHOR]

Allyl ether naphthol resin (ANPF) was synthesized by introducing 1,5‐dihydroxynaphthalene and 2,7‐dihydroxynaphthalene into phenolic resin and was copolymerized with 4,4′‐bismaleimidodiphenylmethane resin (BDM) to obtain allyl ether naphthol‐modified bismaleimide resins (15‐ANPF‐BDM and 27‐ANPF‐BDM). The resulting thermal stability and glass transition temperature (Tg) were explored by thermogravimetric and dynamic mechanical analyses. The char yield of 15‐ANPF‐BDM at a temperature of 800°C was 46.0%. Additionally, the Tg of 15‐ANPF‐BDM was measured as 311°C, which is an increase of 44°C compared to that of c. The mechanical properties of the ANPF‐BDM/quartz fiber (Qf) composites were also investigated. The results reveal that ANPF‐BDM/Qf composites exhibit similar mechanical strength to APF‐BDM/Qf composites at room temperature. In addition, the mechanical properties of the ANPF‐BDM/ Qf composites demonstrated significant improvement in mechanical properties retained significantly improved at 200°C, with a 68% flexural strength retention and a 96% interlaminar shear retention of 15‐ANPF‐BDM/Qf composites. Thus, ANPF‐BDM/Qf composites exhibit outstanding mechanical properties at 200°C. [ABSTRACT FROM AUTHOR]

Novel elastomers are made by reaction of hydroxyl‐terminated polyacrylic ester (HyTemp) with polyethylene glycol (PEG, number of ethylene glycol units 1, 3, 6, 9) based cross‐linkers. The influence of the cross‐linker length, the HyTemp/cross‐linker (w/w) ratio and the cross‐linking accelerator trifluoromethanesulfonate scandium salt (ScTFMS) on the structure and the properties of the materials are studied. The cross‐linker length has not influence on the glass transition (Tg) of the products because of the presence of the flexible PEG units that cancels out the cross‐linking effect associated to a shift to higher Tg. A two‐domain structure is seen by the presence of a dual Tg in samples cured with ScTFMS. Mathematical analysis of the modulated differential scanning calorimetry curves offers for the first time the possibility to identify/confirm structural differences in complex three‐dimensional polymeric structures. Scanning electron microscopy and swelling experiments in ethyl acetate respectively reveal an increase in the pore size (1.13 to 5.48 nm) and in the absorption ability of the elastomers cured with different types and quantities of PEG cross‐linker. The new elastomeric materials are exhibiting a rubbery state over a wide temperature range and absorptivity for the potential recovery of pollutants in soil and/or water. [ABSTRACT FROM AUTHOR]

We report a photochemical method for the semipinacol rearrangement of unactivated allylic alcohols. Aliphatic as well as aromatic groups participate as migrating groups, yielding a variety of α,α‐disubstituted ketones. The reaction proceeds under mild conditions and is compatible with ethers, esters, halides, nitriles, carbamates, and substituted arenes. The operationally simple and fully catalytic conditions prescribe 1 mol % benzothiazinoquinoxaline as organophotocatalyst, 0.5 mol % Co‐salen, and 10 mol % lutidinium triflate and, importantly, display reactivity complementary to procedures employing Brønsted acid. We showcase the utility of the protocol in late‐stage drug diversifications. [ABSTRACT FROM AUTHOR]

The realization of lithium‐metal (Li) batteries faces challenges due to dendritic Li deposition causing internal short‐circuit and low Coulombic efficiency. In this regard, the Li‐deposition stability largely depends on the electrolyte, which reacts with Li to form a solid electrolyte interphase (SEI) with diverse physico‐chemical properties, and dictates the interphasial kinetics. Therefore, optimizing the electrolyte for stability and performance remains pivotal. Hereof, glyme ethers are an emerging class of electrolytes, showing improved compatibility with metallic Li and enhanced stability in Li─Air and Li─Sulfur batteries. Yet, the criteria for selecting glyme solvents, particularly concerning Li deposition and dissolution processes, remain unclear. The SEI characteristics and Li deposition/dissolution processes are investigated in glyme‐ether‐based electrolytes with varying chain lengths, using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium nitrate (LiNO₃) salts under high capacity and limited electrolyte conditions. Longer glymes led to more homogeneous SEI, particularly pronounced with LiNO₃, minimizing surface roughness during stripping, and promoting compact Li deposits. Higher reductive stability, resulting in homogeneous interphasial properties, and slower kinetics due to high desolvation barrier and viscosity, underline stable Li growth in longer glymes. This study clarifies factors guiding the selection of glyme ether‐based electrolytes in Li metal batteries, offering insights for next‐generation energy storage systems. [ABSTRACT FROM AUTHOR]

The 1,3‐difunctionalization of unactivated alkenes is an under‐explored transformation that leads to moieties that are otherwise challenging to prepare. Herein, we report a hypervalent iodine‐mediated 1,3‐difluorination of homoallylic (aryl) ethers to give unreported 1,3‐difluoro‐4‐oxy groups with moderate to excellent diastereoselectivity. The transformation proceeds through a different mode of reactivity for 1,3‐difunctionalization, in which a regioselective addition of fluoride opens a transiently formed oxonium intermediate to rearrange an alkyl chain. The optimized protocol is scalable and shown to proceed well with a variety of functional groups and substitution on the alkenyl chain, hence providing ready access to this fluorinated, conformationally controlled moiety. [ABSTRACT FROM AUTHOR]

We report a mechanistic investigation of an aromatic dithioimide (2SS) displaying puzzling yet efficient photochemistry in ether solvents. Perplexingly, 2SS dissolved in ether solvents in a sealed and degassed vial was photochemically converted to the corresponding diimide (2OO), as determined by 1H NMR following product extraction. With no external sources of oxygen in the sample, could the oxygen in 2OO be from the ether itself? To study this unprecedented proposition, we attempt to uncover the ether's involvement in this reaction. As seen by laser‐flash photolysis, 2SS appears to first react with the solvent from its singlet excited state. Following the reaction by NMR under rigorously oxygen‐ and water‐free conditions led to the identification of a photoreductive pathway that quantitatively transformed one thione into a methylene to yield 2SH2. Subsequent oxidation of 2SH2 or irradiation of 2SS under air proved that molecular oxygen was indeed necessary to observe an oxidative pathway leading to 2OO, ruling out the initially proposed involvement of an ether oxygen. An explanation of 2SS desulfurization was further revealed through the study of solvent by‐products by GC‐MS analysis. Supported by DFT calculations, a mechanism is proposed to involve a chain reaction initiated by photochemically generated ether radical. [ABSTRACT FROM AUTHOR]

Research on the chemoselective metal‐catalyzed hydrogenation of conjugated π‐systems has mostly been focussed on enones. Herein, we communicate the understudied asymmetric hydrogenation of enimines catalyzed by N,P‐iridium complexes and chemoselective toward the alkene. A number of enoxime ethers underwent hydrogenation smoothly to yield the desired products in high yield and stereopurity (up to 99 % yield, up to 99 % ee). No hydrogenation of the C=N π‐bond was observed under the applied reaction conditions (20 bar H2, rt, DCM). It was demonstrated that the chiral oxime ether could be hydrolyzed into the ketone with complete preservation of the installed stereogenity at the α‐carbon. At last, a binding mode of the substrate to the active iridium catalyst and the consequence for the stereoselective outcome was proposed. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal batteries (LMBs) with nickel (Ni)‐rich layered oxide cathodes exhibit twice the energy density of conventional Li‐ion batteries. However, their lifespan is limited by severe side reactions caused by high electrode reactivity. Fluorinated solvent‐based electrolytes can address this challenge, but they pose environmental and biological hazards. This work reports on the molecular engineering of fluorine (F)‐free ethers to mitigate electrode surface reactivity in high‐voltage Ni‐rich LMBs. By merely extending the alkyl chains of traditional ethers, we effectively reduce the catalytic reactivity of the cathode towards the electrolyte at high voltages, which suppresses the oxidation decomposition of the electrolyte, microstructural defects and rock‐salt phase formation in the cathode, and gas release issues. The high‐voltage Ni‐rich NCM811‐Li battery delivers capacity retention of 80 % after 250 cycles with a high Coulombic efficiency of 99.85 %, even superior to that in carbonate electrolytes. Additionally, this strategy facilitates passivation of the Li anode by forming a robust solid‐electrolyte interphase, boosting the Li reversibility to 99.11 % with a cycling life of 350 cycles, which outperforms conventional F‐free ether electrolytes. Consequently, the lifespan of practical LMBs has been prolonged by over 100 % and 500 % compared to those in conventional carbonate‐ and ether‐based electrolytes, respectively. [ABSTRACT FROM AUTHOR]

Silyl ethers fulfil a fundamental role in synthetic organic chemistry as protecting groups and their selective cleavage is an important factor in their application. We present here for the first time two enzymes, SilE−R and SilE−S, which are able to hydrolyse silyl ethers. They belong to the stress‐response dimeric A/B barrel domain (DABB) family and are able to cleave the Si−O bond with opposite enantiopreference. Silyl ethers containing aromatic, cyclic or aliphatic alcohols and, depending on the alcohol moiety, silyl functions as large as TBDMS are accepted. The X‐ray crystal structure of SilE−R, determined to a resolution of 1.98 Å, in combination with mutational studies, revealed an active site featuring two histidine residues, H8 and H79, which likely act synergistically as nucleophile and Brønsted base in the hydrolytic mechanism, which has not previously been described for enzymes. Although the natural function of SilE−R and SilE−S is unknown, we propose that these 'silyl etherases' may have significant potential for synthetic applications. [ABSTRACT FROM AUTHOR]

In this work, semi‐aromatic polyamide containing ether bond (PAE10T) was synthesized through nucleophilic substitution reaction using 1, 10‐N, N′‐bis(4‐fuorobenzamide) decane (BFBD) and hydroquinone (HQ) as the raw materials. And then the composites hydroxyapatite/semi‐aromatic polyamide (40%HA‐PAE10T and 60%HA‐PAE10T) were prepared by chemical precipitation method. Mechanical, SEM, FT‐IR, XRD, DSC, TGA and bioactivity tests were performed to characterize the structure, morphology, thermal and mechanical properties of PAE10T and its composites. Mechanical tests revealed that the difference of HA in weight played an important role in mechanical performance of the composites. Furthermore, in comparison with PAE10T, the 60%HA‐PAE10T showed the highest enhancement in compressive strength (133 MPa) at 75.9%, and the 40%HA‐PAE10T given expression to the best increase in bending strengths (97 MPa) at about 18.4%. The 40%HA‐PAE10T and 60% HA‐PAE10T exhibited the mechanical performances closed to the cortical bone of human. After 28 days of dip in the phosphate buffer saline (PBS), PAE10T, and its composites showed satisfactory stability. The cell culture results showed all composites gad good cytocompatibility, cells attached on the materials well with excellent morphology. All the experimental results showed that the composites were expected to have a good application in the field of compact bone repair. [ABSTRACT FROM AUTHOR]

The interactions between ether naphthotube and a series of dication guests in organic solution were investigated. It was found that ether naphthotube formed stable host‐guest complexes selectively with these guests in a 1 : 1 stoichiometric ratio with association constants ranging from 102 to 106 M−1, which were confirmed by 1H‐NMR spectra and ITC experiments. The host‐guest interactions are driven by enthalpy change as the entropic factors are unfavorable. Positive correlations between ΔH and ΔS have been observed in the host‐guest complexes. Furthermore, the para‐substitution of the guests can significantly affect the binding affinities through a combination of field/inductive and resonance effects by following a linear free energy relationship. Based on the host‐guest complexes composed of ether naphthotube and organic cations, two interlocked [2]rotaxanes were prepared by cationization reaction and Huisgen cycloaddition between the cations and the stopper components. The ether naphthotube‐based host‐guest complexes are useful for creating sophisticated interlocked molecules. [ABSTRACT FROM AUTHOR]

The chemistry of extremely bulky amide ligands is troubled by difficulties in deprotonation of the parent amine. As an alternative route to superbulky amide reagents, the addition of polar reagents to a sila–imine has been investigated. Attempts to synthesize the superbulky amide anion (tBu3Si)2N− by addition of tBuLi to tBu2Si=N(SitBu3) failed and gave tBu3Si(tBu2HSi)NLi and isobutene. Reaction of the sila–imine with KOtBu successfully led to tBu3Si[tBu2(tBuO)Si]NK which crystallized as a separated ion–pair. Reaction with the slightly bulkier KOAd (Ad=1‐adamantyl) led in presence of THF to ether ring–opening. Reaction with tBuOH gave tBu3Si[tBu2(tBuO)Si]NH but this amine cannot be easily deprotonated. Reaction with (BDI*)MgnBu in presence of THF gave (BDI*)Mg+ ⋅ (THF)2 and the non–coordinating anion tBu3Si[tBu2(nBu)Si]N−; BDI*=ß‐diketiminate ligand HC[C(tBu)N−DIPP]2, DIPP=2,6‐diisopropylphenyl. Reaction of Mg(nBu)2 with tBu2Si=N(SitBu3) led to a Mg complex with one amide ligand: tBu3Si[tBu2(nBu)Si]N−. The other superbulky amide anion isomerized by internal deprotonation of a tBu‐substituent to give a primary carbanion that is also coordinated to Mg. Although the amide–to–carbanion isomerization is highly contrathermodynamic, it allows for coordination of both anions to a single Mg center. The new bulky amides are rare cases of halogen–free weakly coordinating anions. [ABSTRACT FROM AUTHOR]

A method for synthesizing silyl arylsulfonyl hydrazones as silyldiazomethane precursors has been developed. Although silyldiazomethanes are an important class of diazo compounds, their use in intramolecular cyclization reactions has not been fully explored despite the rich chemistry of diazo compounds, particularly metal carbenoid chemistry. The fundamental challenge underlying the absence of such studies is the lack of a method for synthesizing silyldiazomethanes with functional groups that can react with metal carbenoids. The method reported here provides access to variety of silyl arylsulfonyl hydrazones with functional groups such as ethers, carbamates, and alkynes, which can serve as reaction sites for metal carbenoids. A one‐pot hydrazone formation using unstable formylsilane formed in situ is key to a successful synthesis. The use of 2,4,6‐trimethylbenzenesulfonohydrazide contributed toward achieving broad generality in hydrazone formation. The synthetic potential of this method was demonstrated through the generation of silyldiazomethane and its transformation to several silacycles. [ABSTRACT FROM AUTHOR]

Herein we report the discovery and development of the first example of a cationic [1,5]‐aryl migration reaction, through an unprecedented phenonium ions. This reaction does not require any acid, base, transition metal‐based catalyst or promoter, instead promoted by the water activated NXS reagents. It provides a highly diastereoselective and rapid access to the medicinally and biologically important tetra‐substituted olefins (allyl alcohols). The involvement of an ipso‐carbon, as well as the phenonium ion during this novel, cationic [1,5]‐aryl migration was strongly supported by the isolation of 2‐oxaspiro[5.5]undecane‐9‐ones. This methodology is highly tolerable for a wide range of propargyl‐benzyl ethers, resulting in a selective construction of structurally divergent library of mono‐halo‐tricarbon‐substituted alkenes. Synthetic application has also been demonstrated by converting two isomeric‐iodo‐olefins to respective E‐ and Z‐isomers of tamoxifen in a stereospecific manner. [ABSTRACT FROM AUTHOR]

A base‐and‐additive‐free photo‐induced radical‐mediated cascade cyclization reaction of 1,6‐enyne compounds was presented. In this study, C(sp3)−H hydrocarbons, including various alkanes and ethers, were activated via Fe‐catalyzed photo‐induced conditions, providing a bunch of γ‐lactam products via hydrogen atom transfer and radical addition processes. Control experiments indicated that the reaction proceeded through photo‐induced ligand‐to‐metal charge transfer (LMCT) process. Gram scale experiment was also completed by using continuous‐flow‐photocatalytic‐device. [ABSTRACT FROM AUTHOR]

The hydrogenolysis of oxygenates such as alcohols and ethers is central to the biomass valorization and also a valuable transformation in organic synthesis. However, a mild and efficient catalyst system for the hydrogenolysis of a large variety of alcohols and ethers with various functional groups is still underdeveloped. Here, we report an aluminum metaphosphate‐supported Pt nanoparticles (Pt/Al(PO3)3) for the hydrogenolysis of a wide variety of primary, secondary, and tertiary alkyl and benzylic alcohols, and dialkyl, aryl alkyl, and diaryl ethers, including biomass‐derived furanic compounds, under mild conditions (0.1–1 atm of H2, as low as 70 °C). Mechanistic studies suggested that H2 induces formation of the surface Brønsted acid sites via its cleavage by supported Pt nanoparticles. Accordingly, the high efficiency and the wide applicability of the catalyst system are attributed to the activation and cleavage of C−O bonds by the hydrogen‐induced Brønsted acid sites with the assistance of Lewis acidic Al sites on the catalyst surface. The high efficiency of the catalyst implies its potential application in energy‐efficient biomass valorization or fine chemical synthesis. [ABSTRACT FROM AUTHOR]

Molecules containing ether skeletons are widely present in drugs, natural products, functional materials, and life science. Direct C(sp3)−H bond ether functionalization is considered a powerful strategy for the construction of novel ether derivatives. Photo‐/electro‐chemical technology is a relatively green and sustainable synthesis method, which opens up a broad application prospect in the field of direct functionalization of C(sp3)−H bonds. In recent years, photo‐/electro‐mediated C(sp3)−H bond alkylation, arylation, alkynylation, esterification, mercaptoylation, sulfidation, and amination of ethers have been extensively studied. In this review, the research progress of photo‐/electro‐mediated C(sp3)−H bond functionalization of ether compounds from 2014 to 2023 is systematically reviewed, and the scope, limitations, and mechanisms for some reactions are discussed. [ABSTRACT FROM AUTHOR]

In this paper, sulfonic acid functionalized benzothiazole ionic liquid ([(CH2)3SO3HBth] [H2PO4]) and graphene oxide were combined together through the cation‐π. The sulfonated poly (ether ether ketone) was doped with ionic liquid‐modified GO (IL‐GO) to prepare the SPEEK/IL‐GO composite membrane through the solution casting method. The SO3H and benzothiazole rings act as both proton acceptors and proton donors during proton transport and can replace the role of water in medium‐ and high‐temperature environments, increasing the proton transport sites to a certain extent and increasing the proton conductivity of the SPEEK/IL‐GO composite membrane. The proton conductivity of the SPEEK/IL‐GO‐2 composite membrane achieved an 18.02 mS/cm at 120°C, which is 2.43 times higher than that of the pristine SPEEK membrane. This paper provided a method for increasing proton conductivity and limiting IL loss of the SPEEK membrane. Highlights: [(CH2)3SO3HBth][H2PO4] and graphene oxide were combined through cation‐π.The benzothiazole ring and SO3H form acid–base pairs.The proton conductivity of SPEEK/IL‐GO‐2 membrane achieved 18.02 mS/cm. [ABSTRACT FROM AUTHOR]

Poly(ethylene oxide) (PEO)‐based electrolytes are often used for Li+ conduction as they can dissociate the Li salts efficiently. However, high entanglement of the chains and lack of pathways for rapid ion diffusion limit their applications in advanced batteries. Recent developments in ionic covalent organic frameworks (iCOFs) showed that their highly ordered structures provide efficient pathways for Li+ transport, solving the limitations of traditional PEO‐based electrolytes. Here, we present imidazolate COFs, PI‐TMEFB‐COFs, having methoxyethoxy chains, synthesized by Debus–Radziszewski multicomponent reactions and their ionized form, Li+@PI‐TMEFB‐COFs, showing a high Li+ conductivity of 8.81 mS cm−1 and a transference number of 0.974. The mechanism for such excellent electrochemical properties is that methoxyethoxy chains dissociate LiClO4, making free Li+, then those Li+ are transported through the imidazolate COFs' pores. The synthesized Li+@PI‐TMEFB‐COFs formed a stable interface with Li metal. Thus, employing Li+@PI‐TMEFB‐COFs as the solid electrolyte to assemble LiFePO4 batteries showed an initial discharge capacity of 119.2 mAh g−1 at 0.5 C, and 82.0 % capacity and 99.9 % Coulombic efficiency were maintained after 400 cycles. These results show that iCOFs with ether chains synthesized via multicomponent reactions can create a new chapter for making solid electrolytes for advanced rechargeable batteries. [ABSTRACT FROM AUTHOR]

Methylenecyclobutenes are useful precursors to provide other organic compounds. We report intermolecular [2+2] cycloaddition of allene ethers and alkynes at 100 °C, which gives methylenecyclobutenes in 50–60 % yields. The reaction does not require any metal catalyst and shows broad substrate scope, high regioselectivity and high stereoselectivity. [ABSTRACT FROM AUTHOR]

In this study, sulfonated poly(arylene ether sulfone) (SPAES) and sulfonated poly(arylene ether ketone) (SPAEK) were randomly synthesized, employing a presulfonation process. This presulfonation process resulted in a more controlled and reproducible sulfonation level. The respective polymers were prepared using 2,2‐Bis(4‐hydroxyphenyl) propane at 50% molar ratio, which also provided some membrane elasticity. The resulting polymers, each had 25% of the block containing the sulfonic domains (SPAES A 25 and SPAEK A 25). Better conductive membranes were achieved for the random sulfone polymers than for the random ketone polymers, with values, respectively, of 0.24 and 0.07 S cm−1 at 80°C. The lower proton conductivity from the ketone‐based polymer was compensated with very low methanol permeability (0.25 × 10−6 cm2 s−1) and outstanding oxidative stability. The selectivity of both polymer membranes exceeded the reported values for the state‐of‐the‐art Nafion® 117 and other commercially available options. Both polymer membranes, with their unique combination of ionic domains, elastomeric blocks, and resulting morphology, could be viable candidates for fuel cell applications. [ABSTRACT FROM AUTHOR]

A convenient and operationally trivial protocol to access synthetically versatile vinylboronates through CuI catalyzed hydroboration and carboboration of alkynes utilizing bis(pinacolato)diboron (B2pin2) as the boron precursor in a 1, 10‐phenanthroline (phen) ligand environment is reported. This is a highly efficient and practical method for the synthesis of regio‐ and stereoselective (E)‐β‐vinylboronates from simple aromatic and aliphatic alkynes. These organoboron compounds have further been utilized for the synthesis of allyl‐vinyl ethers, which are potential starting materials for the Claisen rearrangement via an improved CuII mediated coupling of allyl alcohols and vinylboronates. The vinylboronates were also subjected to Suzuki‐Miyaura cross coupling reaction, allowing access to the corresponding tri‐ and tetra‐substituted alkenes with good isolated yields. [ABSTRACT FROM AUTHOR]

We report herein the development of palladium‐catalyzed deacylative deuteration of arylketone oxime ethers. This protocol features excellent functional group tolerance, heterocyclic compatibility, and high deuterium incorporation levels. Regioselective deuteration of some biologically important drugs and natural products are showcased via Friedel–Crafts acylation and subsequent deacylative deuteration. Vicinal meta‐C−H bond functionalization (including fluorination, arylation, and alkylation) and para‐C−H bond deuteration of electro‐rich arenes are realized by using the ketone as both directing group and leaving group, which is distinct from aryl halide in conventional dehalogenative deuteration. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The reductive cross‐coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great challenge. Herein, we report a reductive cross‐coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis, which constitutes an efficient protocol for the synthesis of a range of functionalized arylsilanes. The combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes, allowing their cross‐coupling in a reductive fashion. The low‐valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed, which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o‐amide auxiliary. [ABSTRACT FROM AUTHOR]

This study aims to find more efficient ways to manufacture highly reactive polyisobutylene (HRPIB) and modified conventional PIB materials (MCPIB) industrially with high vinyl exo‐group contents through cationic polymerization at mild temperatures. The study performed polymerizations using aluminum trichloride (AlCl3) as a catalyst with different nonpolar solvents (hexane and toluene), reaction temperatures (10 and 30°C), and co‐catalysts (water and dibutyl ether [DBE]). At 30°C, toluene can provide vinyl contents above 30 mol%. Particularly, an important synergetic effect was observed between toluene and ether, as corroborated by statistical analyses, resulting in vinyl contents above 50 mol%, while reactions performed in n‐hexane provided maximum vinyl content of 20 mol%. In all cases, number average molar masses ranged from 200 to 1000 Da, which are typical of CPIB and MCPIB materials. Moreover, addition of excess of ether indicated the likely inhibition of reaction rates in presence of high ether concentrations (≥1.18 × 10 −1 mol/L). The obtained results indicated that AlCl3 can be used successfully to manufacture MCPIB products with terminal vinyl contents above 50 mol% at mild temperatures in common nonpolar solvents (n‐hexane and toluene) and in presence of common co‐catalysts (water and DBE) with high rates of reactions. [ABSTRACT FROM AUTHOR]

An N‐allylation of monosubstituted acyl hydrazines with allylic alcohols has been developed by using B(C6F5)3 catalysis. This protocol allows for convenient access to various synthetically useful N‐allylated hydrazine products in 48–96% yields with broad substrate scope and wide functional group compatibility. The operationally simple reaction proceeds without calling for stringent removal of air and moisture, and can be readily scaled up to gram scale. Preliminary mechanistic studies support the generation of an allylic carbon cation that is involved in the catalytic cycle, and the reaction proceeds via the in situ formation of diallyl ethers as intermediates. [ABSTRACT FROM AUTHOR]

We designed and synthesized thirty novel quinoxaline aryl ethers as anticancer agents, and the structures of final compounds were confirmed with various analytical techniques like Mass, 1H NMR, 13C NMR, FTIR, and elemental analyses. The compounds were tested against three cancer cell lines: colon cancer (HCT‐116), breast cancer (MDA‐MB‐231), prostate cancer (DU‐145), and one normal cell line: human embryonic kidney cell line (HEK‐293). The obtained results indicate that two compounds, FQ and MQ, with IC50 values < 16 μM, were the most active compounds. Molecular docking studies revealed the binding of FQ and MQ molecules in the active site of the c‐Met kinase (PDB ID: 3F66, 1.40 Å). Furthermore, QikProp ADME prediction and the MDS analysis preserved those critical docking data of both compounds, FQ and MQ. Western blotting was used to confirm the impact of the compounds FQ and MQ on the inhibition of the c‐Met kinase receptor. The apoptosis assays were performed to investigate the mechanism of cell death for the most active compounds, FQ and MQ. The Annexin V/7‐AAD assay indicated apoptosis in MDA‐MB‐231 cells treated with FQ and MQ, with FQ (21.4%) showing a higher efficacy in killing MDA‐MB‐231 cells than MQ (14.25%). The Caspase 3/7 7‐AAD assay further supported these findings, revealing higher percentages of apoptotic cells for FQ‐treated MDA‐MB‐231 cells (41.8%). The results obtained from the apoptosis assay conclude that FQ exhibits better anticancer activity against MDA‐MB‐231 cells than MQ. [ABSTRACT FROM AUTHOR]

A novel coating for stir bar sorptive extraction was developed by growing a covalent organic framework, TpPa‐1 (derived from phenylenediamine and 1,3,5‐trimethylphloroglucinol), onto the surface of Ni‐Al layered double hydroxide. Using a poly(ether ether ketone) tube as the supporting substrate, a TpPa‐1/layered double hydroxide–coated stir bar was fabricated and demonstrated excellent extraction performance for Sudan dyes. Notably, its extraction efficiency significantly exceeded that of stir bars modified with only TpPa‐1 or Ni‐Al layered double hydroxide. Based on this innovative coating, a stir bar sorptive extraction‐high performance liquid chromatography method was established. This method exhibited low limits of detection (0.04–0.08 ng/mL) for the analysis of Sudan dyes. It also featured a wide linear range (0.25–100 or 200 ng/mL) and demonstrated good repeatability with relative standard deviations ≤6.22%. The recoveries obtained for spiked lake water and chili powder samples were 93.5%–105.2% and 87.8%–100.6%, respectively, demonstrating the practical potential of the developed method for detecting trace Sudan dyes in real samples. [ABSTRACT FROM AUTHOR]

Aromatic nucleophilic substitution polymerization was used to synthesize five poly(ether nitrile imide)s (PENIs) that include benzonitrile and bulky cardo groups from a mixture of phenolphthalein (PP), 4,4′‐bis(4‐fluorophthalimide) diphenyl ether (4,4′‐BFPI), and 2,6‐difluorobenzonitrile (DFBN). The structure and properties relationship of PENIs with different ratios of DFBN and 4,4′‐BFPI was explored. It was found that the glass transition temperature (Tg) of PENIs decreased from 280 to 260°C, while the temperature of 5% thermal weight loss (T5%) in N2 increased from 429 to 453°C as the benzonitrile content in PENI increased. The produced PENI films had good mechanical characteristics, including tensile strengths of 103–112 MPa, elongations at break of 5.6%–8.2%, and tensile moduli of 2.9–3.4 GPa. Furthermore, the solubility and melt processability were also improved with the introduction of the benzonitrile group. Compared with poly(ether ketone imide)s (PEKIs) and poly(ether sulfone imide)s (PESIs), PENIs with benzonitrile displayed higher Tg, tensile modules, and lower complex viscosity. [ABSTRACT FROM AUTHOR]

Membrane‐based gas separations are crucial for an energy‐efficient future. However, it is difficult to develop membrane materials that are high‐performing, scalable, and processable. Microporous organic polymers (MOPs) combine benefits for gas sieving and solution processability. Herein, we report membrane performance for a new family of microporous poly(arylene ether)s (PAEs) synthesized via Pd‐catalyzed C−O coupling reactions. The scaffold of these microporous polymers consists of rigid three‐dimensional triptycene and stereocontorted spirobifluorene, endowing these polymers with micropore dimensions attractive for gas separations. This robust PAE synthesis method allows for the facile incorporation of functionalities and branched linkers for control of permeation and mechanical properties. A solution‐processable branched polymer was formed into a submicron film and characterized for permeance and selectivity, revealing lab data that rivals property sets of commercially available membranes already optimized for much thinner configurations. Moreover, the branching motif endows these materials with outstanding plasticization resistance, and their microporous structure and stability enables benefits from competitive sorption, increasing CO2/CH4 and (H2S+CO2)/CH4 selectivity in mixture tests as predicted by the dual‐mode sorption model. The structural tunability, stability, and ease‐of‐processing suggest that this new platform of microporous polymers provides generalizable design strategies to form MOPs at scale for demanding gas separations in industry. [ABSTRACT FROM AUTHOR]

In this work, we conducted a study of 7‐exo‐trig cyclizations mechanism involving aryl, vinyl, and alkyl radicals on oxime ethers. Initially, the reaction of brominated oxime ether 9 a with (TMS)3SiH and AIBN gave rise to aryl radicals that underwent a 7‐exo‐trig cyclization on the oxime ether, yielding dibenzoxepine 10 a, and the ipso reaction and reduction products were obtained as well. Approximate rate constants at 80 °C for the 7‐exo‐trig (1.0×108 s−1) and the ipso cyclization (4.3×107 s−1) were determined by competition experiments. DFT calculations showed good agreement with the experimental results. The reduction rate constant of the N‐alkoxyaminyl radical with (TMS)3SiH was calculated to be 4.1×10−1 M−1 s−1; while the rate constants for the 7‐exo‐trig cyclizations of vinyl and alkyl radicals on the oxime ether were estimated in the ranges of 106 s−1–108 s−1 and 103 s−1–108 s−1, respectively. The 7‐exo‐trig cyclization reactions involving aryl, vinyl, and alkyl radicals with oxime ethers were found to be an exothermic and irreversible process, with the oximic carbon showing a preference for nucleophilic alkyl radicals. This kinetic study contributes to the deeper understanding of radical‐mediated cyclizations, enabling the efficient design of complex synthetic routes. [ABSTRACT FROM AUTHOR]

A novel method to prepare asymmetric amine ethers is reported. Tertiary amine alcohol hydrogen sulfate intermediates are prepared through a reactive distillation process, followed by the transesterification process to afford eventually asymmetric amine ethers. Experiments and DFT calculations revealed the essential roles the sulfate group plays in the highly selective monoesterification process. This clean method is tolerant towards various functional groups with good yields under mild condition, which is obviously superior compared to the conventional processes. [ABSTRACT FROM AUTHOR]

The anionic ring‐opening copolymerization of commercially available bio‐based cardanol glycidyl ether (CGE) was investigated without any prior purification. As a first step, anionic‐ring‐opening homopolymerization was attempted through active chain‐end and monomer‐activated mechanisms. Both strategies were unsuccessful. Conversely, in a second step, the anionic alternating ring‐opening copolymerization (AAROP) of CGE with the renewable N‐acetyl homocysteine thiolactone (NHTL) was successfully carried out in the presence of a strong base. Anisole, a solvent classified as sustainable and rarely used in anionic ring‐opening polymerization, proved to be a suitable for the AAROP. This polymerization is an unusual example of synthesis of linear polyesters with cardanol‐based monomers. The copolymers were carefully characterized by 1H, 13C, COSY, HSQC, 1H‐15N NMR and MALDI‐ToF, demonstrating an alternating structure. Then, CGE was copolymerized with NHTL and another additional epoxide. The cardanol‐derived monomers enable the preparation of functionalizable poly(ester‐alt‐thioether) bearing multiple allyl and alkene groups. The AAROP method in anisole offers new opportunity for green anionic polymerization through the use of sustainable chemicals, witnessed by the valorization of cardanol‐derived compounds and expands the scope of synthesized renewable polyesters. [ABSTRACT FROM AUTHOR]

An operationally simple anhydrous carbene insertion reaction to construct DNA‐encoded libraries (DEL) is reported. The developed reaction employs visible light photolysis of diazo compounds and Reversible Adsorption to Solid Support (RASS) strategy. From readily available amines, alcohols, phenols, and carboxylic acids, a variety of high‐value molecules, including useful unnatural amino acids, ethers, and esters, promising clinical drug derivatives, and bioactive molecules have been constructed. [ABSTRACT FROM AUTHOR]

Axially chiral diaryl ethers are present in numerous natural products and bioactive molecules. However, only few catalytic enantioselective approaches have been established to access diaryl ether atropisomers. Herein, we report the N‐heterocyclic carbene‐catalyzed enantioselective synthesis of axially chiral diaryl ethers via desymmetrization of prochiral 2‐aryloxyisophthalaldehydes with aliphatic alcohols, phenol derivatives, and heteroaromatic amines. This reaction features mild reaction conditions, good functional group tolerance, broad substrate scope and excellent enantioselectivity. The utility of this methodology is illustrated by late‐stage functionalization, gram‐scale synthesis, and diverse enantioretentive transformations. Control experiments and DFT calculations support the association of NHC‐catalyzed desymmetrization with following kinetic resolution to enhance the enantioselectivity. [ABSTRACT FROM AUTHOR]

New derivatives of crown compounds were successfully prepared via multicomponent reactions of a thia‐podand, an β‐keto ester and ammonium acetate based on modifications of the Petrenko‐Kritschenko reaction. The structure of the synthesized compounds was identified by physical‐chemical methods of analysis including IR, NMR, HRMS, and single‐crystal X‐ray diffraction. In addition, an in vitro assay against the α‐glucosidase of synthetic compounds was first evaluated and showed positive results. The most active compound exhibited an IC50 value of 5.69±0.27 μM, which is 37 fold more potent than the standard drug of acarbose (IC50 208.42±4.68 μM). Furthermore, prediction of ADMET parameters revealed that almost all synthesized trithiacrown ether derivatives expressed drug‐like characteristics. Our results provide useful evidence that crown ether compounds are not only good chelators with metal ions but also scaffolds for developing lead candidates in the treatment of diabetic disease. [ABSTRACT FROM AUTHOR]

2,2,6,6‐Tetramethylpiperidinium‐nitroxide (TEMPO) is a mild and efficient catalyst, which is important in the industrial production of selective oxidation of alcohols to the corresponding aldehyde or ketone compounds. However, it is a challenge to recover the expensive TEMPO catalyst in homogeneous catalytic systems. In this study, a novel polymer‐supported catalyst was prepared using 4‐hydroxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxy (4‐OH‐TEMPO) and polyaromatic ether sulfone (PAES). The successful grafting of 4‐OH‐TEMPO in PAES‐C was demonstrated by 1H nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT‐IR), load capacity can be calculated by elemental analysis (EA). BET and scanning electron microscopy (SEM) to depict the structure‐performance relationship. Herein, SEM images revealed the existence of porous structure. This structure can effectively adsorb NO molecules to form a PAES‐TEMPO/NOx catalytic system to selectively oxidize benzyl alcohol. The experimental results indicated the high activity, the subsequent benzyl alcohol oxidation cycle can reach more than 93% conversion without showing a large loss of selectivity. More importantly, the as‐prepared catalyst exhibited the attractive recyclability (recovery rate is 98%). After 10 consecutive runs, no significant loss of conversion and selectivity was observed (the conversion rate of benzyl alcohol was more than 93% and the selectivity was more than 95%). This study might provide some recommendation on the development of highly efficient catalysts for alcohol oxidation. [ABSTRACT FROM AUTHOR]

The Cp*Co(III) C−H allylation of (hetero)arenes with allyl aryl ethers has been developed using an amide as directing group (24 examples). DFT calculations have shed light on the mechanistic course and reactivity pattern, showing that strong electron releasing groups favour the reaction by reducing the activation barrier of the rate‐determining C−H activation step. However, the steric strain can increase the energy of the migratory insertion step to the point of completely preventing the reaction, as in the case of the 3,5‐dimethylbenzamide. The obtained allylated compounds have been transformed into a variety of interesting heterocyclic and carbocyclic structures, such as isoquinolones and isochromanones. [ABSTRACT FROM AUTHOR]

The following paper proposes a modern method of obtaining an extract from Viola tricolor L. with a high rutin content and enhanced antioxidant activity. Conventional isolation of active substances from plant raw material is high‐cost, elaborate and often harmful to the environment. The ultrasonic assistance micelle‐mediated extraction method (UAMME) and the cloud‐point extraction/separation technique are interesting alternatives. This work discusses the relationship between salt concentration and the cloud‐point extraction (CPE) yield. The molecular dynamic simulations investigated the impact of hydrocarbon chain length and the ratio of oxyethylene/oxypropylene units of model surfactants on the interactions between extraction system components. Micellar extract from the Viola tricolor was obtained using C9‐11 Pareth‐5 at 1 wt/vol% and subsequently concentrated by CPE with the addition of NaCl in concentrations from 5% to 30%. For comparison, water and ethanol extracts were also prepared. Antioxidant properties, polyphenols and flavonoid contents were measured for all samples. The HPLC method was used to determine the rutin concentration. The simulation part of the study confirmed the dependence of bioflavonoid solubilization efficiency on the surfactant structure. The determined descriptors allowed for finding the optimal structure of the model surfactants and gave a hint for their application to obtain extracts with high concentrations of antioxidants. [ABSTRACT FROM AUTHOR]

An expedient synthesis of silyl ethers is reported via photocatalytic free radical coupling of ketones with hydrosilanes and subsequent [1, 2]‐Brook rearrangement. This strategy features the advantages of 100 % atom economy, environmental friendliness, easily available starting materials as well as late‐stage functionalization of complex molecules. [ABSTRACT FROM AUTHOR]