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The ring-opening reaction of aromatic molecules is a significant and critical process for the construction of carbon-based and related functional materials with desired structures and properties. However, direct observation and control of such a process at a molecular level remains a challenge. Here, we employed the octahedral voids in endohedral metallofullerene (EMF) crystals as nanoreactors to accommodate aromatic m-xylene molecules and regulate the ring-opening reaction of guest m-xylene by applying a high pressure. We found that the ring-opening reaction of m-xylenes strongly depends on the degree of charge transfer between m-xylene and EMF, which can be tuned by varying the electronegativity of the carbon cages with different endohedral metals. A positive relationship between the electronegativity of fullerenes and the reactivity of m-xylene was revealed. This work demonstrates the potential of tuning the ring-opening reaction of aromatic molecules by charge transfer and manipulates the reaction at a molecule level, providing new insights into the synthesis of carbon materials and fullerene derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of interconnected hollow carbon spheres functionalized with B and Tb single atoms. • B doping increases the Lewis acidity of Tb, promoting the occurrence of rate-determining step of ring-opening reaction. • The prepared TbN 4 B 2 /C can adsorb full band light to achieve efficient photothermal conversion. • The CO 2 cycloaddition reaction with using TbN 4 B 2 /C as catalyst is a photothermal synergistic catalytic mechanism. Nowadays, it is becoming increasingly urgent to lower the escalating carbon dioxide (CO 2) to reduce greenhouse effect. Fortunately, it is an ideal strategy by using the inexhaustible solar energy as the driving force to manipulate the cycloaddition reaction, the atomic efficiency of which is 100 %. This work represents the first attempt on utilization of rare-earth metal Tb with atomic dispersion, and the structure of Tb coordinated with 4 N -atoms and 2B-atoms was constructed on interconnected carbon hollow spheres. The introduction of electron-deficient B reduces the electron density of Tb, thereby boosting Lewis acidity and promoting the occurrence of ring-opening reaction. The mechanism exploration enunciates that TbN 4 B 2 /C is a photothermal synergistic catalyst, the combined action of photogenerated electrons and strong Lewis acidic site of Tb reduces the free energy of the rate-determining step, and then improving the yield of cyclic carbonate up to 739 mmol g-1h−1. [ABSTRACT FROM AUTHOR]

The Chemical Communications journal, published by The Royal Society of Chemistry, features a variety of research articles on topics such as anion recognition, chemiluminescent systems, and ion-pair recognition. The journal includes contributions from researchers worldwide, covering areas like solar energy, biomedical advancements, and catalytic functionality. Articles in this issue discuss advancements in various chemical fields, including optical sensing, catalysis, and materials science, providing valuable insights for researchers and scholars in the chemistry community. [Extracted from the article]

The first synthesis of 3,4-diarylpyrimido[1,2-b]indazole derivatives from 3-aminoindazoles has been realized. The FeCl3-catalyzed intermolecular epoxide ring-opening reaction altered the order of annulation, with the free primary NH2 groups in 3-aminoindazoles preferentially reacting with styrene oxides instead of aromatic aldehydes. This protocol is further highlighted by its broad substrate compatibility, high chemo- and regioselectivities, and the late-stage modifications of bioactive molecules. Without aromatic aldehydes, the synthesis of 3-aryl-4-acylpyrimido[1,2-b]indazole derivatives can also be accomplished using alternative reaction conditions. [ABSTRACT FROM AUTHOR]

Selenium-containing molecules represent a valuable class of compounds with a variety of applications in chemical and biological fields. Selenated reagents are used as intermediates to introduce functional groups (e.g., double bonds) onto different substrates or in the synthesis of various selenated derivatives. Among the variety of selenium-containing reagents, silyl selenides are frequently used to transfer a selenated moiety due to the smooth functionalization of the Se-Si bond, which allows for the generation of selenium nucleophilic species under mild conditions. While the use of the analogous sulfur nucleophiles, namely silyl sulfides, has been widely explored, a relatively limited number of reports on selenosilanes have been provided. This contribution will focus on the application of selenosilanes as nucleophiles in a variety of organic transformations, as well as under radical and redox conditions. The use of silyl selenides to prepare metal complexes and as selenium precursors of materials for atomic layer deposition will also be discussed. [ABSTRACT FROM AUTHOR]

Phosphorus chemistry occupies a pivotal position in contemporary organic chemistry but significant synthetic challenges still endure. In this report, a class of electrophilic phosphiranium salts, bearing fluorinated benzyl quaternizing groups, is introduced for the direct synthesis of diversely β-functionalized phosphines. We show that, in comparison with regular quaternary phosphiranium salts, these species display the sought balance of excellent stability and high electrophilic reactivity that allow the unlocking of the C-centered ring-opening reactions with different classes of weak nitrogen-, sulfur- and oxygen protic nucleophiles. In the arena of strained heterocyclic chemistry, phosphacycles as appealing electrophilic P-containing building blocks are underestimated. Here, the authors report a class of electrophilic phosphiranium salts bearing fluorinated benzyl quaternizing groups for the direct synthesis of diverselyβ-functionalized phosphines. [ABSTRACT FROM AUTHOR]

The document is the contents list for the journal "Chemical Communications" published on September 25, 2024. It includes various articles on topics such as responsive DNA hydrogels, lithium metal-based battery systems, and strategies in photochemical alcohol oxidation. The journal is published by The Royal Society of Chemistry, a leading chemistry community, and aims to connect the world with the chemical sciences. [Extracted from the article]

Chiral carbon nanodots (CNDs) were fabricated through the hydrothermal processing of sulfanilic acid and chiral tartaric acid, exhibiting outstanding catalytic performance for the chiral catalysis of the ring-opening reaction. Furthermore, the catalytic mechanism was proposed to understand the link between the chiral structure and the performance of the catalyst. [ABSTRACT FROM AUTHOR]

Cyclo[n]carbons have recently attracted significant attention owing to their geometric and electronic structures remaining largely unexplored in the condensed phase. In this work, we focus on two anti-aromatic cyclocarbons, namely C12 and C20. By designing two fully halogenated molecular precursors both including 4-numbered rings, we further extend the on-surface retro-Bergman ring-opening reaction, and successfully produce C12 and C20. The polyynic structures of C12 and C20 are unambiguously revealed by bond-resolved atomic force microscopy. More importantly, subtly positioning the C20 molecule into an atomic fence formed by Cl clusters allows us to experimentally probe its frontier molecular orbitals, yielding a transport gap of 3.8 eV measured from scanning tunneling spectroscopy. Our work may advance the field by easier synthesis of a series of cyclocarbons via on-surface retro-Bergman ring-opening strategy. Cyclo[n]carbons have attracted significant attention owing to their geometric and electronic structures remaining largely unexplored in the condensed phase. Here, the authors extend the on-surface retro-Bergman ring-opening reaction and successfully produce two anti-aromatic cyclocarbons C12 and C20. [ABSTRACT FROM AUTHOR]

In light of the small ring strain of five/six-membered cyclic ethers, constructing complex molecules via ring-opening reactions has consistently been a highly challenging topic in organic synthesis. Induced by Lewis acids, the charge redistribution in cyclic ethers forms oxonium ylide intermediates, thereby activating the C–O bond and subsequently facilitating nucleophilic attack for ring opening. In recent years, a variety of novel Lewis acids, encompassing those with new metal centers and frustrated Lewis pairs (FLPs), have been effectively utilized to induce the formation of oxonium ylides, offering a diverse array of methods for the ring opening of five/six-membered cyclic ethers. This review conveys the extensive application advancements of diverse Lewis acid types for cyclic ether ring-opening reactions over the past two decades, originating from the perspective of the classification of Lewis acids. Furthermore, the substrate applicability and chemical transformation efficiency of these Lewis acids in the ring-opening reactions of cyclic ethers have also been discussed herein. [ABSTRACT FROM AUTHOR]

There are great challenges in the field of natural product isolation and purification and in the pharmacological study of oligosaccharide monomers. And these isolation and purification processes are still universal problems in the study of natural products (NPs), traditional Chinese medicine (TCM), omics, etc. The same polymer-modified materials designed for the special separation of oligosaccharides, named Sil-epoxy-PEI and Sil-chloropropyl-PEI, were synthesized via two different methods and characterized by scanning electron microscopy combined with energy spectrum analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential as well as surface area analysis, etc. Several nucleotide/nucleoside molecules with different polarities and selectivities were successfully isolated in our laboratory using stainless-steel columns filled with the synthesized material. In addition, the separation of saccharide probes and oligosaccharides mixtures in water extracts of Morinda officinalis were compared in HILIC mode. The results showed that the resolution of separations for the representative analytes of the Sil-epoxy-PEI column was higher than for the Sil-chloropropyl-PEI column, and the developed stationary phase exhibited improved performance compared to hydrothermal carbon, amide columns and other HILIC materials previously reported. [ABSTRACT FROM AUTHOR]

In order to further enhance the erosion resistance of cement concrete pavement materials, this study constructed an apparent rough hydrophobic structure layer by spraying a micro-nano substrate coating on the surface layer of the cement concrete pavement. This was followed by a secondary spray of a hydroxy-silicone oil-modified epoxy resin and a low surface energy-modified substance paste, which combine to form a superhydrophobic coating. The hydrophobic mechanism of the coating was then analysed. Firstly, the effects of different types and ratios of micro-nano substrates on the apparent morphology and hydrophobic performance of the rough structure layer were explored through contact angle testing and scanning electron microscopy (SEM). Subsequently, Fourier transform infrared spectroscopy and permeation gel chromatography were employed to ascertain the optimal modification ratio, temperature, and reaction mechanism of hydroxy-silicone oil with E51 type epoxy resin. Additionally, the mechanical properties of the modified epoxy resin-low surface energy-modified substance paste were evaluated through tensile tests. Finally, the erosion resistance of the superhydrophobic coating was tested under a range of conditions, including acidic, alkaline, de-icer, UV ageing, freeze-thaw cycles and wet wheel wear. The results demonstrate that relying solely on the rough structure of the concrete surface makes it challenging to achieve superhydrophobic performance. A rough structure layer constructed with diamond micropowder and hydrophobic nano-silica is less prone to cracking and can form more "air chamber" structures on the surface, with better wear resistance and hydrophobic performance. The ring-opening reaction products that occur during the preparation of modified epoxy resin will severely affect its mechanical strength after curing. Controlling the reaction temperature and reactant ratio can effectively push the modification reaction of epoxy resin through dehydration condensation, which produces more grafted polymer. It is noteworthy that the grafted polymer content is positively correlated with the hydrophobicity of the modified epoxy resin. The superhydrophobic coating exhibited enhanced erosion resistance (based on hydrochloric acid), UV ageing resistance, abrasion resistance, and freeze-thaw damage resistance to de-icers by 19.41%, 18.36%, 43.17% and 87.47%, respectively, in comparison to the conventional silane-based surface treatment. [ABSTRACT FROM AUTHOR]

This study reports the degradation of hydroquinone using lab-scale hydrodynamic cavitation approach (aswirl-type micro-nano bubble reactor), which is considered a green and effective method. The effects of inlet pressure, gas flow rate, pH and initial hydroquinone concentration on hydroquinone degradation were analysed based on experimental research. After experiments investigation, it was concluded that with pH 7.38, hydroquinone concentration of 50 mg/L, and int pressure of 0.2 MPa, the degradation efficiency of hydroquinone reached 91.25% in wastewater. Furthermore, this study also investigated the degradation effect of hydroquinone wastewater by hydrodynamic cavitation combined with persulfate oxidation (HC + PS). The kinetics of hydroquinone degradation by HC or PS oxidation alone and HC + PS oxidation were also examined. Compared with the degradation method alone, the degradation of hydroquinone by HC + PS was more pronounced, and the enhancement factor was 4.55, which indicates that HC greatly enhances the oxidation capacity of PS. In additon, from viewpoint of energy consumption and operating cost, the synergy of HC + PS (1.05 mM) is also the most promising combination. Based on the detection results of the Gas chromatography-mass spectrometry (GC-MS) the possible degradation pathways of hydroquinone were analysed: under the action of ·OH and the high temperature and pressure by cavitation process, the hydroquinone molecule undergoes dehydrogenation and ring-opening reaction, demethylation and decarboxylation reaction to produce intermediate products, which are finally converted into CO2 and H2O in micro-nano bubble cavitation process. [ABSTRACT FROM AUTHOR]

Polyurethanes are the result of a reaction between an isocyanate and a polyol. The large variety of possible reagents creates many possible polyurethanes to be made, such as soft foams, rigid foams, coatings, and adhesives. This polymer is one of the most produced and consumed polymers in the world with an ever-increasing demand. Despite its usual petrochemical nature, research on bio-based polyurethanes flourishes due to the ease in creating bio-based polyols. This work covers the synthesis of a novel macauba kernel oil polyol by the epoxidation of the oil, followed by a ring-opening reaction of the epoxide with glycerol, used for the preparation of polyurethane foams using different NCO/OH ratios. The FTIR and H1 results confirm the formation of the epoxide and polyol, and the polymers in all NCO/OH ratios were confirmed by FTIR, showing great similarities between the samples, especially PU 1.0 and PU 1.2. Despite the TGs showing close behaviors for the three samples, their DTGs showed great difference between the samples, with PU 1.0 presenting a regular PU DTG profile with three degradation peaks while the other two sample presented five degradation peaks, indicating a higher crosslinking density in them. [ABSTRACT FROM AUTHOR]

In light of the small ring strain of five/six-membered cyclic ethers, constructing complex molecules via ring-opening reactions has consistently been a highly challenging topic in organic synthesis. Induced by Lewis acids, the charge redistribution in cyclic ethers forms oxonium ylide intermediates, thereby activating the C–O bond and subsequently facilitating nucleophilic attack for ring opening. In recent years, a variety of novel Lewis acids, encompassing those with new metal centers and frustrated Lewis pairs (FLPs), have been effectively utilized to induce the formation of oxonium ylides, offering a diverse array of methods for the ring opening of five/six-membered cyclic ethers. This review conveys the extensive application advancements of diverse Lewis acid types for cyclic ether ring-opening reactions over the past two decades, originating from the perspective of the classification of Lewis acids. Furthermore, the substrate applicability and chemical transformation efficiency of these Lewis acids in the ring-opening reactions of cyclic ethers have also been discussed herein.

5‐Hydroxymethylfurfural (HMF) was transformed into 2,5‐diformylfuran (DFF) with nitric acid as the oxidant. The initial HMF content was as high as 12.5 wt %, and water was the sole solvent. This is an intensely exothermic reaction along with the emission of NO2 gas. A high DFF yield of 83.2 % was achieved if the oxidation ability of nitric acid matched with the requirement of target oxidation reaction while mismatched those of side reactions by regulating the initial concentration of nitric acid (59.5 wt %) and reaction temperature (50–60 °C). The oxidation reaction of HMF, overoxidation of HMF, and skeleton‐cracking reaction of FDCA preferred concentrated HNO3, hot HNO3, and concentrated or hot HNO3, respectively. After liquid‐liquid extraction, filtration, and column chromatography, light‐yellow DFF powders with purity of 92.1 wt % and isolated yield of 40.2 % were obtained and confirmed by NMR, FTIR, UV‐Vis, and elemental analysis. HMF was the dominant impurity due to its affinity to DFF. In addition, chromogenic substances were obtained as a byproduct, and they were potential pH indicators. These chromogenic substances had highly conjugated molecular structures, and they were generated via successive β‐protonation‐based ring‐opening reaction of HMF, aldol reaction, and dehydration reaction. [ABSTRACT FROM AUTHOR]

A transition metal‐free synthesis of alkylidene dihydroisobenzofurans from the ortho‐alkynyl allylic alcohols is reported herein. Notably, a simple base tBuOK is utilized for the 5‐exo‐dig cyclization and double bond isomerization of ortho‐alkynyl allylic alcohols to furnish alkylidene dihydrobenzofurans with Z‐stereoselectivity under shorter reaction times. In addition, the geometry of the double bonds was confirmed by 1D Selective Gradient NOESY and 2D NMR (NOESY) analysis. Furthermore, the effectuality of the ortho‐alkynyl allylic alcohols has been shown by extending to the one‐pot synthesis of indanones via aqueous acid‐mediated hydrolysis (ring‐opening) of in‐situ formed dihydroisobenzofurans followed by intramolecular condensation reaction under acidic conditions [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Green Chemistry," published by The Royal Society of Chemistry. It highlights the articles and papers featured in the current issue, covering a range of topics related to sustainable chemistry and green technologies. The articles include research on bio-based polymers, nitrogen fixation strategies, carbon aerogels for energy storage, and the use of ionic liquids in new energy and biotechnologies. The journal aims to provide cutting-edge research for a greener and more sustainable future. [Extracted from the article]

Potassium diphenyl phosphide (KPPh2), which forms a highly nucleophilic phosphide anion, was used as an initiator for the anionic ring-opening polymerization of glycidyl phenyl ether (GPE). GPE was selected as a model compound for the practical application of various glycidyl-type epoxy resins. MALDI-TOF MS analysis of the resulting polymer clarified the presence of a diphenyl phosphine moiety at initiation, confirming that the anionic polymerization was initiated by nucleophilic attack of the phosphide anion on the epoxide. In addition, compared to various basic catalysts such as phosphines and amines, KPPh2 catalyzed the ring-opening addition of epoxide with o-cresol much more efficiently, demonstrating its potential for application to epoxy–phenol curing systems. [ABSTRACT FROM AUTHOR]

Halohydrin dehalogenases (HHDHs) have demonstrated significant potential as biocatalysts for synthesizing industrial heterocyclic compounds and chiral alkanolamines from aromatic substrates with NaOCN that are not feasible through chemosynthesis. To further study the HHDH reaction in real industrial applications, a diverse panel of HHDHs has been screened for their ability to convert aliphatic cyclohexene oxide. By using the best HHDH variant in form of a whole cell biocatalyst, a novel chemical process, regulated by the cascaded chemoenzymatic reactions for pilot‐scale ring‐opening reactions, has been successfully developed. Using the best HHDH hit in whole‐cell form provides a viable bio‐catalytic approach for the synthesis of related fine chemicals. Our research provides a promising strategy for scaling up non‐native ring‐opening reactions from the laboratory to industrial applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Axially chiral biaryls represent the most important class of atropisomers, and they widely exist in natural products and biologically active molecules. They also constitute a unique scaffold for chiral ligands and catalysts in organic synthesis. The development of synthetic methods to obtain such chiral compounds has received widespread attention, among which catalytically atroposelective ring‐opening of configurationally labile compounds represents one of the most attractive strategies. Various substrates with strained cyclic structures, such as the renowned Bringmann's lactones, can undergo asymmetric transformation into stable atropisomers. Known advancement primarily relies on metal catalyst combined with well‐designed chiral ligands, the approaches utilizing organocatalysis as a critical resolution strategy are notably scarce. In this study, we disclosed a N‐heterocyclic carbene (NHC)‐catalyzed asymmetric ring‐opening reaction of biaryl lactams via direct atroposelective nucleophilic activation. The optimized bulky carbene catalyst ensures that the reaction can proceed under mild conditions, affording the desired product with good to excellent yields and atroposelectivity. [ABSTRACT FROM AUTHOR]

Using Ni(II) as the catalyst, electron-deficient 3,5-dimethylacryloylpyrazole olefin was reacted with C,N-diarylnitrones alone for 10 min to prepare novel five-member heterocyclic products, 4-3,5-dimethylacryloylpyrazole isoxazolidines with 100% regioselectivity and up to 99% yield. And then, taking these cycloadducts as substrates, six kinds of derivatization reactions, like ring-opening, nucleophilic substitution, addition-elimination and reduction, were studied. Experimental results showed that all kinds of transformations could obtain the target products at a high conversion rate under mild conditions, a finding which provided the basic methods for organic synthesis methodology research based on an isoxazolidine skeleton. [ABSTRACT FROM AUTHOR]

Piperazines constitute an important structural feature of many pharmaceuticals. For the discovery of new drugs, the ability to modify the lead compound's structure is crucial. Herein, we provide an efficient method for the synthesis of chiral 2,3,5-trisubstituted piperazine structures. Our route enables the synthesis of several novel chiral aryl aziridinyl ketones that could be converted into aziridine-fused bicyclic imines. The reduction of these imines and the nucleophilic ring-opening reaction of the aziridine ring allowed us to synthesize highly functionalized piperazine derivatives. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Axially chiral biaryls represent the most important class of atropisomers, and they widely exist in natural products and biologically active molecules. They also constitute a unique scaffold for chiral ligands and catalysts in organic synthesis. The development of synthetic methods to obtain such chiral compounds has received widespread attention, among which catalytically atroposelective ring‐opening of configurationally labile compounds represents one of the most attractive strategies. Various substrates with strained cyclic structures, such as the renowned Bringmann's lactones, can undergo asymmetric transformation into stable atropisomers. Known advancement primarily relies on metal catalyst combined with well‐designed chiral ligands, the approaches utilizing organocatalysis as a critical resolution strategy are notably scarce. In this study, we disclosed a N‐heterocyclic carbene (NHC)‐catalyzed asymmetric ring‐opening reaction of biaryl lactams via direct atroposelective nucleophilic activation. The optimized bulky carbene catalyst ensures that the reaction can proceed under mild conditions, affording the desired product with good to excellent yields and atroposelectivity. [ABSTRACT FROM AUTHOR]

Green manufacturing and reducing our cultural dependency on petrochemicals have been the global interest currently, especially in the polyurethane industry segments. We report the fabrication of rigid polyurethane foams (RPUFs) and their flame-retardant property from hemp seed oil as an alternative to petrochemical-based polyols. The cold-pressed hemp-seed oil (HSO) was first oxidized to epoxidized triglyceride oils with acetic acid and hydrogen peroxide, followed by a ring-opening reaction with methanol to fabricate hemp bio-polyols. The formation of polyols was characterized using FT-IR, hydroxyl, and acid values. The bio-polyol was used in different proportions with commercial polyols and other foaming ingredients to produce rigid polyurethane foams via a one-step process. Dimethyl methylphosphonate (DMMP), triethyl phosphate (TEP), and expandable graphite (EG) were added during the foam preparation to improve flame retardancy. The produced foams were analyzed for their apparent density, mechanical properties, thermal degradation behavior, closed cell content, flammability, and cellular morphology. The effect of different flame retardants had a significant influence on the cellular structures, closed-cell content, density, and compressive strength of the polyurethane. A significant improvement in anti-flaming properties was observed as the neat HSO-based foam showed a burning time of 110 s and a weight loss of 82%, whereas 10 wt% of TEP displayed a reduced burning time and weight loss of 19 s and 5%, respectively. DMMP and EG-based RPUFs exhibited similar flame retardancy and mechanical properties relative to neat HSO-based foam. The results demonstrated in this work proposed a potential combination of bio-polyols and commercial polyols as a strategy to fabricate flame-retardant polyurethane foam for high-performance applications. [ABSTRACT FROM AUTHOR]

This study explored the catalytic performance of two robust zirconium-based metal–organic frameworks (MOFs), MIP-202(Zr) and UiO-66-(CO2H)2 in the ring-opening of epoxides using alcohols and amines as nucleophilic reagents. The MOFs were characterized by techniques such as FT-IR, PXRD, FE-SEM, and EDX. Through systematic optimization of key parameters (catalyst amount, time, temperature, solvent), MIP-202(Zr) achieved 99% styrene oxide conversion in 25 min with methanol at room temperature using 5 mg catalyst. In contrast, UiO-66-(CO2H)2 required drastically harsher conditions of 120 min, 60 °C, and four times the catalyst loading to reach 98% conversion. A similar trend was observed for ring-opening with aniline –MIP-202(Zr) gave 93% conversion in one hour at room temperature, while UiO-66-(CO2H)2 needed two hours at 60 °C for 95% conversion. The superior performance of MIP-202(Zr) likely stems from cooperative Brønsted/Lewis acid sites and higher proton conductivity enabling more efficient epoxide activation. Remarkably, MIP-202(Zr) maintained consistent activity over five recycles in the ring-opening of styrene oxide by methanol and over three recycles in the ring-opening of styrene oxide by aniline. Testing various epoxide substrates and nucleophiles revealed trends in reactivity governed by electronic and steric effects. The results provide useful insights into tuning Zr-MOF-based catalysts and highlight the promise of the cost-effective and sustainable MIP-202(Zr) for diverse epoxide ring-opening reactions on an industrial scale. [ABSTRACT FROM AUTHOR]

The bio-depolymerization of coal is a promising technology for converting coal into low-molecular-weight industrial chemicals. In this study, we investigated the characteristics of biodepolymerized coal (BDC) and the associated depolymerization pathway. We analyzed the extracellular enzyme activities of Hypocrea lixii AH in the biodepolymerization system, performed Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance spectroscopy (NMR) of BDC, and performed gas chromatography and mass spectrometry (GC/MS) of the BDC methanol extract. Results showed that the activities of peroxidase (POD), polyphenol oxidase (PPO), laccase (Lac), and lignin peroxidase (LiP) were 1377, 162, 10, and 1.919 U, respectively. Following biodepolymerization by Hypocrea lixii AH, 20 organic compounds were identified. Benzaldehyde 4-hydroxy-3,5-dimethoxy was the most dominant at 33.16%, followed by (Z)-9-octadecenamide, accounting for 14.73%. The aromaticity (fa) decreased from 54.3% to 23.7%, suggesting ring-opening reactions catalyzed by LiP and Lac. The ratio of carbonyl carbon (faC) increased from 8.3% to 16.2%, suggesting oxidation reactions catalyzed by POD. By comparing the structure of the Fushun oxidized coal model and BDC, a biodepolymerization pathway was elucidated. Biodepolymerization of Fushun oxidized coal is an oxidation–depolymerization process catalyzed by a series of enzymes, which breaks the aromatic rings and oxidizes side chains. Altogether, our findings provide a theoretical support for the chemical application of BDC. [ABSTRACT FROM AUTHOR]

Highlights In this work, we prepare epoxidized aramid pulp (AP) by grafting ethylene glycol diglycidyl ether (EGDE) onto the surface of AP via poly catechol/polyamine (PCPA). Subsequently, we premix the epoxidized AP with carboxylated nitrile butadiene rubber (XNBR) to induce a chemical reaction with the carboxyl group in XNBR. The carboxylated nitrile butadiene rubber/cis‐polybutadiene rubber/aramid pulp (XNBR/BR/AP) composites are prepared by mechanical blending. Water contact angle, FTIR, and XPS confirm the grafting of EGDE onto AP via an epoxy group ring‐opening reaction. The rheological performance results indicate that the addition of EGDE decreases the curing time of the composites and increases the degree of cross‐linking of the composites. The compatibility between AP and rubber is analyzed by SEM, and it is deduced that the interfacial bonding between AP and composite is enhanced by EGDE. The tensile strength, tear strength, abrasion resistance, and solvent resistance of the composites are significantly improved after EGDE modification. RPA results show that the modified AP is uniformly dispersed in the composites and reduces the rolling resistance of the composites. A new and effective strategy is provided for the surface functionalization of aramid pulp meal, which has a wide range of rubber industry applications. Composite mechanical properties increase with increasing EGDE content. Rheological properties of composites improved by EGDE incorporation. EGDE improves filler dispersion, reduced rolling resistance of composites. Increased interfacial bonding between AP and rubber due to EGDE. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

The alkylation of arenes is one of the most fundamental transformations in synthetic chemistry and the transition‐metal‐catalyzed direct C−H alkylation represents a straightforward and attractive approach from both atom and step‐economy perspectives. Epoxides, the smallest three‐membered saturated O‐heterocycles that can be easily prepared in racemic or enantioenriched forms, are highly useful building blocks for the synthesis of complex organic molecules. Owing to their inherent high ring‐strain, epoxides readily undergo ring‐opening reactions and have been used as alkylating reagents for C−H alkylation catalyzed by transition metals. This review summarizes recent advances in utilizing epoxides as alkylating reagents in transition‐metal‐catalyzed C−H alkylation as well as their synthetic applications in organic synthesis. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

The document is the contents list for the journal "Chemical Communications" published on July 21, 2024. It includes the editorial, cover image, and highlights of the issue. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The contents list includes feature articles and communications on various topics in chemistry, such as supramolecular chemistry, organocatalysis, metal-organic frameworks, and electrochemistry. The document provides a glimpse into the research and discoveries in the field of chemistry. [Extracted from the article]

The rich reactivity profile of cyclopropanes has been extensively explored to trigger new organic transformations that enable unusual disconnective approaches to synthesize molecular motifs that are not easily reached through conventional reactions. In particular, the chemistry of cyclopropanes has received special attention in the last decade, with multiple new approaches that capitalize on the use of organocatalysis for the activation of the cyclopropane scaffold. This situation has also opened the possibility of developing enantioselective variants of many reactions that until now were only carried out in an enantiospecific or diastereoselective manner. Our group has been particularly active in this field, focusing more specifically on the use of aminocatalysis and Brønsted acid catalysis as major organocatalytic activation manifolds to trigger new unprecedented transformations involving cyclopropanes that add to the current toolbox of general methodologies available to organic chemists for the enantioselective synthesis of chiral compounds. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

The electrochemical advanced oxidation process (EAOP) has shown significant promise in the field of refractory organic wastewater treatment due to its high efficiency and environmentally friendly nature. In this study, Ti/Sb-SnO2 electrodes with varying proportions of Hf were prepared using the sol–gel method. The addition of Hf transformed the original collapsing and broken surface into a flat and regular surface. The results demonstrated that Ti/Sb-SnO2-Hf electrode doped with 6% Hf exhibited a higher oxygen evolution potential (OEP) and excellent stability. The OEP increased from 2.315 V without Hf-doping to 2.482 V, and the corresponding actual life was 321.05% higher than that without Hf. The current density (5–40 mA·cm−2), electrolyte concentration (0.02–0.2 mol·L−1), pH (3–11), and initial pollutant concentration (5–80 mg·L−1) were evaluated to confirm the tetracycline (TC) degradation characterization of Ti/Sb-SnO2-6%Hf electrodes. It was concluded that under the optimal degradation conditions, the removal rate of TC could reach 99.66% within 2 h. The degradation of TC follows first-order reaction kinetics. The oxidative degradation of TC was achieved through indirect oxidation, with ·OH playing a dominant role. TC's electrochemical oxidation degradation pathway has been proposed: Based on LC–MS results, three main pathways are speculated. During the electrocatalytic oxidation process, decarboxylation, deamidation, and ring-opening reactions occur under ·OH attack, producing intermediate compounds with m/z values of 427, 433, 350, 246, 461, 424, 330, 352, 309, 263, and 233. These intermediates are further oxidized to intermediate compounds with an m/z value of 218. This work introduces a new efficient anode electrochemical catalyst for the degradation of TC, providing a strategy for industrial applications. [ABSTRACT FROM AUTHOR]

We present herein an approach for the enantioselective C3-functionalization of 2,1-benzothiazine 2,2-dioxides using N-heterocyclic carbene (NHC) catalysis. Our method involves a sequence of [3+3] cycloaddition and ring-opening reactions with different N- and O-nucleophiles, followed by silylation. Overcoming the challenge of selectivity targeting the C3 position, this protocol demonstrates a broad substrate scope and high enantioselectivity. This marks a significant advancement in the field of NHC-catalyzed transformations. [ABSTRACT FROM AUTHOR]

With phenacyl chlorides as simple nucleophilic species, the asymmetric Darzens reaction of isatins using Ni(acac)2 as the Lewis acid and imidazolidine‐pyrroloimidazolone pyridine as the ligand is reported. In the presence of 1 mol% of the catalyst, diverse spiro‐epoxyoxindoles with two new contiguous stereocenters were afforded in 82–99% yields, >20:1 dr, with 91–99% ee. Chiral spiro‐epoxyoxindoles could undergo ring‐opening reactions in further transformations. The developed method was applied to the derivatization of complex molecules including indomethacin, gemfibrozil, and febuxostat‐derived α‐chloroketones. A strong positive nonlinear effect was observed, which was caused by the precipitation of a less‐soluble racemic catalyst complex. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of biocompatible three different maleic anhydride co-polymer conjugated with two different beta-lactam antibiotics at in vitro conditions were conducted. The polymer–drug conjugates were synthesized by coupling β-lactam antibiotics via amide bonds to the copolymer. In this work, six different drug-functionalized maleic anhydride copolymers (DFMACs) were synthesized by the chemical conjugation method. This method is based on the ring-opening reaction of the anhydride ring of the copolymer to form an amide bond linking the drug. The synthesized DFMACs were characterized by 1H NMR and FTIR/ATR spectroscopies and analyses were carried out by UV/VIS spectroscopy and Zeta-sizer instrument in detail with consecutive antibacterial tests. The existence of a newly formed amide covalent bond between the drug and the copolymer chains was confirmed by 1H NMR and FTIR/ATR studies. This is the first report on the application of the selected branched biodegradable polymeric matrices for the covalent conjugation of ampicillin and cefalexin. Optimum stability and activity conditions for the synthesized DFMACs were determined. Analyses were conducted under in vitro conditions including varying pH values and simulated body fluids as a function of time to obtain new drug delivery system candidates for the two different antibiotics. [ABSTRACT FROM AUTHOR]

A novel synthesis method has been developed for the construction of functionalized 2,4-diarylpyridines. The reaction involves several key processes, including a reduction reaction, Michael reaction, decarboxylation, intramolecular cyclization, oxidation, ring-opening and aromatization reaction. All of these processes are facilitated by heating a mixture of the starting materials in an environmentally benign solvent, propylene carbonate (PC), with the oxidant (air) and the catalyst Cu(OAc)2. This cascade reaction not only forms two new bonds but also cleaves three existing bonds in a single pot. The protocol presented in this study is a valuable tool for synthesizing functionalized unsymmetrical 2,4-diarylpyridines. [ABSTRACT FROM AUTHOR]

The elucidation of the ring–opening reaction mechanism is a critical step towards improving the catalytic performance for the conversion of biomass into value–added chemicals. Herein, we focused on the stepwise C−O bond hydrogenolysis mechanism of oxygen–containing heterocycles (O‐heterocycles) into α,ω‐diols, in particular THFA to 1,5‐PeD, over selective Ni−La(OH)3 in hydrogen–donor isopropanol. A mechanistic study was carried out on a structurally well–defined Ni−La(OH)3, where the mechanism was elucidated using a combination of kinetic and 13C NMR isotope labeling experiments. It was suggested that both Ni nanoparticles and La(OH)3 support play a critical role in the reaction mechanism, where basic hydroxide species of the support initially deprotonate the CH2OH and −OH modified furan, tetrahydrofuran and tetrahydropyran rings, adsorbing them chemically on the catalyst surface. This step is followed by a direct hydride attack on the second carbon atom of these rings, which is proposed to be the key step for ring cleavage, as indicated by the increased deuteration at this position. In addition to the direct hydrogenolysis using gaseous H2, it is assumed that a catalytic transfer hydrogenolysis reaction (CTH) reaction of THFA is proposed to proceed via the dehydrogenation of isopropanol over isolated Ni species, forming hydrogen species that can be adsorbed on the Ni surface or desorb as H2 molecules. [ABSTRACT FROM AUTHOR]

Homogeneous electrocatalysts can indirect oxidate the high overpotential substrates through single‐electron transfer on the electrode surface, enabling efficient operation of organic electrosynthesis catalytic cycles. However, the problems of this chemistry still exist such as high dosage, difficult recovery, and low catalytic efficiency. Single‐atom catalysts (SACs) exhibit high atom utilization and excellent catalytic activity, hold great promise in addressing the limitations of homogeneous catalysts. In view of this, we have employed Fe‐SA@NC as an advanced redox mediator to try to change this situation. Fe‐SA@NC was synthesized using an encapsulation‐pyrolysis method, and it demonstrated remarkable performance as a redox mediator in a range of reported organic electrosynthesis reactions, and enabling the construction of various C−C/C−X bonds. Moreover, Fe‐SA@NC demonstrated a great potential in exploring new synthetic method for organic electrosynthesis. We employed it to develop a new electro‐oxidative ring‐opening transformation of cyclopropyl amides. In this new reaction system, Fe‐SA@NC showed good tolerance to drug molecules with complex structures, as well as enabling flow electrochemical syntheses and gram‐scale transformations. This work highlights the great potential of SACs in organic electrosynthesis, thereby opening a new avenue in synthetic chemistry. [ABSTRACT FROM AUTHOR]

There is a pressing need for methods that can connect enantioenriched organic compounds with readily accessible building blocks via asymmetric functionalization of unreactive chemical bonds in organic synthesis and medicinal chemistry. Herein, the asymmetric chemoselective cleavage of two unactivated C(Ar)−O bonds in the same molecule is disclosed for the first time through an unusual nickel‐catalyzed carbomagnesiation. This reaction facilitates the evolution of a novel atroposelective ring‐opening difunctionalization. Utilizing readily available dibenzo bicyclic substrates, diverse valuable axially chiral biaryls are furnished with high efficiencies. Synthetic elaborations showcase the application potential of this method. The features of this method include good atom‐economy, multiple roles of the nucleophile, and a simple catalytic system that enables the precise magnesiation of an α‐C(Ar)−O bond and arylation of a β‐C(Ar)−O bond. [ABSTRACT FROM AUTHOR]

This article, published in the journal Synlett, discusses a study on the development of a rhodium-catalyzed direct vinylene annulation reaction. The researchers focused on using vinyl selenones as vinylene-transfer reagents and successfully demonstrated a three-component reaction to construct isoquinolone scaffolds. The article includes a table showing the optimization of reaction conditions. The study also explored the scope and limitations of the reaction system, proposing a mechanism for the coupling reaction and concluding that further optimization is needed. [Extracted from the article]

The syntheses of the neutral molybdenum imido alkylidene N‐heterocyclic carbene (NHC) complexes of the general formula [Mo(NAr)(CHCMe2Ph)(NHC)XY] (Ar=2‐tBu‐C6H4, 2‐CF3‐C6H4, 2,6‐Me2‐C6H3, 2,6‐Cl2‐C6H3, adamantyl; X, Y=OTf, OC(CF3)3, OCH(CF3)2, OC6F5, SC6F5, 2,5‐bis(pentafluorophenyl)phen‐1‐yl) bearing electron‐withdrawing NHCs (1,3‐dimethyl‐4,5‐dichloroimidazol‐2‐ylidene (IMeCl2), 1,3,4‐triphenyl‐1,2,4‐triazol‐5‐ylidene (TPT)) are reported. Complementary, the corresponding cationic molybdenum imido alkylidene NHC complexes of the general formula [Mo(NAr)(CHCMe2R)(NHC)X+][B(ArF)4−/Al(OC(CF3)3)4−] (R=Me, Ph; B(ArF)4−=tetrakis (3,5‐bis(trifluoromethyl)phenyl)borate) have been prepared. Aiming at tungsten oxo complexes, reaction of [W(O)Cl2(CHCMe2Ph)(PMe2Ph)2] with [1,3‐dimethyl‐4,5‐dichloroimidazol‐2‐ylidene⋅AgI] (IMeCl2⋅AgI) followed by the addition of lithium terphenoxide yields [W(O)(CHCMe2Ph)(IMeCl2)(DPPO)2]. For comparison, [W(O)Cl(CHCMe2Ph)(IMes)(OSi(OtBu)3)] was prepared via reaction of [W(O)Cl2(CHCMe2Ph)(PMe2Ph)(IMes)] with KOSi(OtBu)3. [W(O)(CHCMe2Ph)(IMeCl2)(DPPO)(Et2O)+][B(ArF)4−] (DPPO=2,6‐diphenylphenoxide) became accessible via reaction of [W(O)(DPPO)2(CHCMe2Ph)(IMeCl2)] with anilinium B(ArF)4−. The structural peculiarities of selected complexes are reported. Benchmark ring‐closing metathesis and homometathesis reactions revealed that the neutral complexes bearing weakly coordinating NHCs such as IMeCl2 and TPT possessed only moderate activity, which could, however, be improved by preparing the corresponding cationic metal alkylidene complexes. [ABSTRACT FROM AUTHOR]

Ring-opening addition reaction between a tri-aziridine, pentaerythriyol-tris[3-(1-aziridinyl)propionate] (AZOH) or 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] (AZ), and a thiol-carboxylic acid, thioglycolic acid (TGA) or thiolactic acid (TLA) or 3-mercaptopropionic acid (MPA), at room temperature in ethyl acetate produced porous polymers. The polymer networks were formed by the ring-opening reactions between the aziridine group of the tri-aziridine compounds with both the carboxylic acid and thiol groups of the thiol-carboxylic acids. The morphology of the porous polymers was composed by connected particles, whose averaged diameters ranged from about 2.5 to 7.5 µm. The reaction of AZOH and MPA under a high monomer concentration (40 wt%) yielded the porous polymer with co-continuous monolithic structure, whose backbone was formed by connected small particles of diameters of less than 0.2 µm. The porous polymers formed with TLA showed higher Young's modulus due to small particle size and high density. The porous polymers showed good thermal stability. All porous polymers were decomposed in methanol within 50 days at room temperature. [ABSTRACT FROM AUTHOR]

The remote C(sp3)‐SCN bond formation via ring‐opening functionalization of cycloalkanols with N‐thiocyanatosaccharin as the precursor of SCN radicals and pyrylium salt as the organic photocatalyst under visible light has been developed. Thus, various terminal keto thiocyanates were prepared without transition metals and oxidants in moderate to good yields. The simplicity, wide substrate scope and mild conditions feature its synthetic application capability. [ABSTRACT FROM AUTHOR]

This article discusses the importance of peptides in scientific research and the need for sustainable methods of peptide synthesis. It introduces the use of trialkylaluminum as a solution for protecting amide NH bonds in diketopiperazines (DKPs), which are important in peptide elongation. The study demonstrates a method for synthesizing mono-Boc-DKPs and their potential use in forming peptide bonds. The article also discusses previous methods and challenges associated with DKPs. The article includes a table showing the results of reactions using trialkylaluminum and provides information on yields and selectivity. The authors found that the use of trialkylaluminum with silicon reagents yielded the desired results and demonstrated the scalability and applicability of the method. [Extracted from the article]

Reactive open-shell ring systems comprising C, N, O, and S atoms are crucial for the radiation-induced molecular evolution and relevant to life and interstellar regions. Herein, we targeted the dehydro radical isomers derived from five-membered heterocycles pyrazole 1, isothiazole 2, and isoxazole 3. Using electronic structure and unimolecular decomposition-based mechanistic calculations, we attempted to envisage the variables influencing the thermodynamic and kinetic stability of radical isomers 1a–1d, 2b–2d and 3b–3d. Evidence suggests that the factors including (hetero)aromaticity, the radical electron's role in delocalization (resonance), and the ring strain play a significant role. The N-centered pyrazole radical 1a was found to be entirely delocalised, which impacts its higher thermodynamic and kinetic stability. Conversely, the C-centered radicals (1b–1d, 2b–2d, and 3b–3d) show important contributions from the interaction between the radicals and lone pair electrons, evident from the NBO analysis. The mechanistic studies through unimolecular decomposition channels show the importance of ring-opening channels as the decisive factor in their kinetic stability. Preferential cleavage of X–N or C–X bonds and formation of fragmented products like acetylene, HCN, HNC, CO, CS, NHCCH radicals, SCCH radicals, OCCH radicals, HNNC radicals, SNC radicals, and ONC radicals were also characterized. [ABSTRACT FROM AUTHOR]

A Mn‐electrocatalytic ring‐opening azidation of tert‐cyclobutanols has been developed. The regioselective method is applicable for the azidation of a diverse array of cyclobutanols to provide practical γ‐azido ketones in 23–91% yields under chemical oxidants‐free reaction conditions. Detailed mechanistic studies suggest the process of Mn‐mediated alkoxy radical generation followed by β‐scission to form carbon‐centered radical species is possibly involved in this transformation. [ABSTRACT FROM AUTHOR]