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We report copper(II) and copper(III) trifluoromethyl complexes supported by a pyridinedicarboxamide ligand (L) as a platform for investigating the role of electron transfer in C(sp2)−H trifluoromethylation. While the copper(II) trifluoromethyl complex is unreactive towards (hetero)arenes, the formal copper(III) trifluoromethyl complex performs C(sp2)−H trifluoromethylation of a wide range of (hetero)arenes. Mechanistic studies using the copper(III) trifluoromethyl complex suggest that the mechanism of arene trifluoromethylation is substrate‐dependent. When the thermodynamic driving force for electron transfer is high, the reaction proceeds through a previously unidentified single electron transfer (SET) mechanism, where an initial electron transfer occurs between the substrate and oxidant prior to CF3 group transfer. Otherwise, a CF3 radical release/electrophilic aromatic substitution (SEAr) mechanism is followed. These studies provide valuable insights into the role of strong oxidants and potential mechanistic dichotomy in Cu‐mediated C(sp2)−H trifluoromethylation. [ABSTRACT FROM AUTHOR]

The growing demand for cost‐effective and sustainable energy‐storage solutions has spurred interest in novel anode materials for lithium‐ion batteries (LIBs). In this study, the potential of small‐molecule polycyclic aromatic hydrocarbons (SMPAHs) as promising candidates for LIB anodes is explored. Through a comprehensive experimental approach involving electrode fabrication, material characterization, and electrochemical testing, the electrochemical performance of SMPAHs, including naphthalene, biphenyl, 9,9‐dimethylfluorene, phenanthrene, p‐terphenyl, and pyrene (Py), is thoroughly investigated. In the results, the impressive cycle stability, high specific capacity, and excellent rate capability of the SMPAH electrode are revealed. Additionally, a direct contact prelithiation strategy is implemented to enhance the initial Coulombic efficiency (ICE) of SMPAH anodes, yielding significant improvements in the ICE and cycle stability. Computational simulations provide valuable insights into the electrochemical behavior and lithium‐storage mechanisms of SMPAHs, confirming their potential as effective anode materials. The simulations reveal favorable lithium adsorption sites, the predominant storage mechanisms, and the dissolution mechanism of Py through computational calculations. Overall, in this study, the promise of SMPAHs is highlighted as sustainable anode materials for LIBs, advancing energy‐storage technologies toward a greener future. [ABSTRACT FROM AUTHOR]

We describe novel amine‐mediated transformation of alkynyl ketones and amides to generate 2‐methylene‐2H‐pyrans, substituted 3‐hydroxy‐9H‐fluoren‐9‐ones, and amine‐incorporated arenes. These cascade processes are initiated by conjugate addition of secondary amine followed by hydrolysis of the enamine/vinylogous amide intermediates. The product distribution is highly sensitive to the steric and electronic effects of the substituents on both the alkyne moieties, the tether structure connecting them, and the nature of the amine. Alkynyl amide participates in the Alder‐ene reaction favorably to generate more reactive allene amide that reacts with amine to generate amine‐incorporated arene products. These metal‐free cascade reactions are a useful synthetic method that can be exploited for the construction of various hetero‐ and carbocyclic systems. [ABSTRACT FROM AUTHOR]

We describe the use of acyl imidazoles derived from aliphatic carboxylic acids for the N-heterocyclic carbene/organic photoredox co-catalyzed meta -selective functionalization of electron-rich arenes. Compared to our previous work, a change of the wavelength of the applied LED light from 440 nm to 390 nm promotes this reaction efficiently. [ABSTRACT FROM AUTHOR]

Functionalized 1,2,4,5-tetrasubstituted benzenes are synthetically difficult or laborious to access. The Rh-catalyzed [2+2+2] cycloaddition of a diyne and internal alkyne offers a seemingly straightforward route to these scaffolds; however, this has been largely restricted to alkynes bearing activating (coordinating) functional groups, with very few examples of unactivated alkynes. In this work, we disclose an assessment of Rh-catalyzed [2+2+2] cycloadditions employing unactivated internal alkynes, focusing on the structural diversity and compatibility of both alkyne and diyne components. The limitations of this method are disclosed, with exceptionally bulky alkynes and specific functional groups undergoing side reactions. Furthermore, the practicalities of gram-scale reactions and catalyst recovery/reuse are demonstrated. [ABSTRACT FROM AUTHOR]

The formation of carbon‐fluorine (C−F) bonds is an important research field in organic synthesis because inserting a fluorine atom into an organic compound can alter its physicochemical properties, such as metabolic stability and permeability. Due to this unique property, organic fluorinated compounds, especially aryl fluorides, have a wide range of applications in various fields, including agrochemicals, pharmaceuticals, and materials science. Therefore, numerous metal‐ or metal‐free‐mediated fluorination reactions have been developed to synthesize aryl fluorides. In this mini‐review, we summarize recent ten years' advances in fluorination reactions for the synthesis of aryl fluorides. [ABSTRACT FROM AUTHOR]

Although dearomative functionalizations enable the direct conversion of flat aromatics into precious three‐dimensional architectures, the case for simple arenes remains largely underdeveloped owing to the high aromatic stabilization energy. We herein report a dearomative sequential addition of two nucleophiles to arene π‐bonds through umpolung of chromium–arene complexes. This mode enables divergent dearomative carbonylation reactions of benzene derivatives by tolerating various nucleophiles in combination with alcohols or amines under CO‐gas‐free conditions, thus providing modular access to functionalized esters or amides. The tunable synthesis of 1,3‐ or 1,4‐cyclohexadienes as well as the construction of carbon quaternary centers further highlight the versatility of this dearomatization. Diverse late‐stage modifications and derivatizations towards synthetically challenging and bioactive molecules reveal the synthetic utility. A possible mechanism was proposed based on control experiments and intermediate tracking. [ABSTRACT FROM AUTHOR]

Catalytic olefin hydroamination reactions are some of the most atom‐economical transformations that bridge readily available starting materials–olefins and high‐value‐added amines. Despite significant advances in this field over the last two decades, the formal hydroamination of nonactivated aromatic compounds remains an unsolved challenge. Herein, we report the extension of olefin hydroamination to aromatic π‐systems by using arenophile‐mediated dearomatization and Cu‐catalysis to perform 1,2‐hydroamination on nonactivated arenes. This strategy was applied to a variety of substituted arenes and heteroarenes to provide general access to structurally complex amines. We conducted DFT calculations to inform mechanistic understanding and rationalize unexpected selectivity trends. Furthermore, we developed a practical, scalable desymmetrization to deliver enantioenriched dearomatized products and enable downstream synthetic applications. We ultimately used this dearomative strategy to efficiently synthesize a collection of densely functionalized small molecules. [ABSTRACT FROM AUTHOR]

The synthetic relevance of bicyclo[2.2.2]octadienes is witnessed by their successful application in various chemical domains, promoting a recurrent interest in the concise assembly of these bridged bicycles. Seminal examples of strategies to craft these compounds are presented, together with more-recent applications that exploit visible light. In this context, a general intramolecular method for the para -cycloaddition of an allenamide arm onto simple aryl rings is highlighted. [ABSTRACT FROM AUTHOR]

The intramolecular coupling of dichloro‐substituted helically fused anthracenes using the Yamamoto coupling yielded cyclized products with sterically congested molecular structures. The X‐ray analysis and DFT calculations showed that the aromatic framework adopted a nonplanar structure with a twisted conformation about the newly formed single bond, which acts as a chiral axis. Interestingly, the X‐ray structure obtained through the Hirshfeld atom refinement revealed short interatomic distances between the inner hydrogen atoms (1.648–1.692 Å), much shorter than the sum of their van der Waals radii. Owing to these unusually short contacts, the 1H NMR spectrum exhibited a significant deshielding (12.5 ppm) and a large nuclear Overhauser effect (44 %). Additionally, the IR spectrum displayed a high‐frequency shift of the C−H stretching vibration. These observations, along with the noncovalent interaction plot indicative of a characteristic steric environment, strongly support the presence of steric hindrance. Moreover, dynamic NMR measurement of the mesityl‐substituted derivative yielded a barrier to helical inversion of 84 kJ mol−1. The optical properties and crystal packing of the cyclized products are also reported. [ABSTRACT FROM AUTHOR]

The electrophilic activation of various substrates via double or even triple protonation in superacidic media enables reactions with extremely weak nucleophiles. Despite the significant progress in this area, the utility of organophosphorus compounds as superelectrophiles still remains limited. Additionally, the most common superacids require a special care due to their high toxicity, exceptional corrosiveness and moisture sensitivity. Herein, we report the first successful application of the "Brønsted acid assisted Brønsted acid" concept for the superelectrophilic activation of 2-hydroxybenzo[e][1,2]oxaphosphinine 2-oxides (phosphacoumarins). The pivotal role is attributed to the tendency of the phosphoryl moiety to form hydrogen-bonded complexes, which enables the formation of dicationic species and increases the electrophilicity of the phosphacoumarin. This unmasks the reactivity of phosphacoumarins towards non-activated aromatics, while requiring only relatively non-benign trifluoroacetic acid as the reaction medium. [ABSTRACT FROM AUTHOR]

This article presents trioxa[9]circulene (3) as a novel member of hetero[n]circulenes. Its synthesis began with the synthesis of dimethoxydioxa[8]helicene (5) and used dimethoxydiepoxycyclononatrinaphthalene (4) as a key intermediate, despite the condensation reaction predominantly yielding a 1,4‐addition byproduct. The structures and properties of 3–5 were extensively investigated using experimental and computational methods. Analysis of the crystal structures reveal elongation of the internal C−C bonds in the nine‐membered ring of 3 compared to 4 and 5. Computational studies demonstrate the remarkable flexibility of trioxa[9]circulene's saddle‐shaped polycyclic framework, while the other two compounds are rigid with large racemization barriers. Optically pure forms of 4 and 5 exhibit absorption and luminescence dissymmetry factors on the order of 10−2, with smaller values observed for compound 4. In the crystal structures, molecules of 3 stack to form columns with remarkable π–π overlap, and the π–π interactions of 4 exhibit short intermolecular C‐to‐C contacts. Consequently, the solution‐processed film of 4 functioned as a p‐type organic semiconductor in field effect transistors. [ABSTRACT FROM AUTHOR]

Organic fluorophores that efficiently emit ultraviolet (UV) light in the solid state are expected to accelerate the development of potentially attractive UV‐OLEDs. Herein, we demonstrate that 2′,5′‐dialkoxy‐, 2′,5′‐bis(siloxy)‐, and 2′‐(alkoxy)‐5′‐(siloxy)‐p‐terphenyls and 2,5‐dioxy‐1,4‐(1‐naphthyl)benzenes are efficient UV‐emitting solid fluorophores. The teraryls were prepared by a Pd‐catalyzed Suzuki–Miyaura cross‐coupling reaction of readily available 2,5‐dialkoxy‐1,4‐diiodobenzenes with phenyl‐ and (1‐naphthyl)boronic acid, followed by dealkylation–silylation. The dioxy‐p‐teraryls are thermally stable, with some having glass transition temperatures ranging from −8 to 47 °C. Single‐crystal X‐ray diffraction analysis of 2′,5′‐bis(triphenylsiloxy)‐ and 2′‐(hexyloxy)‐5′‐(triphenylsiloxy)‐p‐terphenyls revealed that the terphenyl moieties adopted twisted conformations, and there were no intramolecular π–π interactions in the crystal packing. The terphenyls in CH2Cl2 fluoresced at 370–386 nm with quantum yields of 0.30–0.44. Efficient UV emission (362–391 nm) of the teraryls was observed in the solid state, with quantum yields of 0.20–0.46. Density functional calculations suggest that the optical excitation of the terphenyls involves intramolecular charge transfer from the ethereal oxygen, with the moieties accepting the charge transfer depending on the substituents on the ethereal oxygen atoms. [ABSTRACT FROM AUTHOR]

Four dicationic palladium and platinum ethylene complexes of the type [M(PNP)(C2H4)]X2 (M=Pd, Pt; X=BF4, SbF6, PNP=2,6‐bis(diphenylphosphinomethyl)pyridine) were studied as pre‐catalysts for the intermolecular hydroarylation of acetylene under acid‐free conditions. The palladium complex [Pd(PNP)(C2H4)](SbF6)2 was found to be the most active catalyst for the addition of pentamethylbenzene to acetylene at room temperature. In a 31P NMR spectroscopic study the impact of the counter anion on the rate determining step was demonstrated. Various reaction parameters were screened to optimize the catalytic efficiency. The presence of small amounts of water were beneficial and increased the reaction rate. Water acts as co‐catalyst assisting in proton transfer during the catalytic reaction. After optimization of the reaction conditions, a benchmark for the palladium(II) catalyzed hydroarylation of acetylene was achieved with TON 200 at room temperature in 24 h under acid‐free conditions. However, this catalytic system has a very limited substrate scope. [ABSTRACT FROM AUTHOR]

The “precursor approach” has proved particularly valuable for the preparation of insoluble and unstable π-conjugated polycyclic compounds (π-CPCs), which cannot be synthesized via in-solution organic chemistry, for their improved processing, as well as for their electronic investigation both at the material and single-molecule scales. This method relies on the synthesis and processing of soluble and stable direct precursors of the target π-CPCs, followed by their final conversion in situ, triggered by thermal activation, photoirradiation or redox control. Beside well-established reactions involving the elimination of carbon-based small molecules, i.e., retro-Diels–Alder and decarbonylation processes, the late-stage extrusion of chalcogen fragments has emerged as a highly promising synthetic tool to access a wider variety of π-conjugated polycyclic structures and thus to expand the potentialities of the “precursor approach” for further improvements of molecular materials’ performances. This review gives an overview of synthetic strategies towards π-CPCs involving the ultimate elimination of chalcogen fragments upon thermal activation, photoirradiation and electron exchange.

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure. Herein, we synthesized a series of novel Cu-based catalysts, Cu@NS-SiO2 (NS = nano sphere) and alkali metals (Na, K, Rb, and Cs) doped Cu@NS-SiO2, and applied them in hydrodeoxygenation reaction of anisole. High Cu dispersion was presented on all catalysts. The modification of alkali metals on Cu@NS-SiO2 significantly enhanced the electron density of Cu sites in the following order: Cs > Rb > K > Na, among which Cs decreased the Cu 2p3/2 binding energy most (by 0.7 eV). Moreover, the modification did not substantially affect the geometric structure of Cu species. This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole, and thus promoted the selectivity of benzene. Compared with Cu@NS-SiO2 (∼59%), the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO2 at ∼83%.

This review summarizes the studies on the palladium carboxylate π-complexes with unsaturated hydrocarbons (alkenes, alkynes, and arenes) as well as with N-heterocyclic carbenes, phosphonyl-substituted ferrocene ligands, etc. In these complexes the palladium atoms are coordinated with unsaturated hydrocarbons via the carbon atoms forming the multiple bonds. These complexes are traditional objects in fundamental coordination chemistry including chemistry of polynuclear compounds. They are also applied as pre-catalysts and as model intermediates for catalytic transformations of unsaturated hydrocarbons, e.g., oxidation and isomerization of alkenes, hydrogenation and coupling reactions of alkenes, alkynes, and arenes. [ABSTRACT FROM AUTHOR]

An assorted set of sulfonyl arenes such as β‐naphthylamines, β‐naphthols, phenols and naphthalenes could be accessed in a divergent manner by base‐mediated annulation of sulfonyl enynals. The strategy is extended to the synthesis of heterocycles such as carbazole, quinoline and benzothiophene. Benzannulation is demonstrated on derivatives of natural steroids like estrone and cholesterol. [ABSTRACT FROM AUTHOR]

Highly oxygenated cyclohexanes, including (amino)cyclitols, are featured in natural products possessing a notable range of biological activities. As such, these building blocks are valuable tools for medicinal chemistry. While de novo synthetic strategies have provided access to select compounds, challenges including stereochemical density and complexity have hindered the development of a general approach to (amino)cyclitol structures. This work reports the use of arenophile chemistry to access dearomatized intermediates which are amenable to diverse downstream transformations. Practical guidelines were developed for the synthesis of natural and non‐natural (amino)cyclitols from simple arenes through a series of strategic functionalization events. [ABSTRACT FROM AUTHOR]

In this study, we explore feasibility of the mechanochemical approach in the synthesis of tetrabenzofluorenes (fluoreno[5]helicenes). For this, commercially available phenylated cyclopentadiene precursors are subjected to the Scholl reaction in the solid state using FeCl3 as an oxidant and sodium chloride as the solid reaction medium. This ball milling process gave access to the 5‐membered ring containing‐helicenes in one synthetic step in high (95–96 %) isolated yields. The solution‐phase reactions, however, were found to be moderate to low yielding in this regard (10–40 %). [ABSTRACT FROM AUTHOR]

The given text is a collection of scientific documents discussing the synthesis and characterization of various compounds. The compounds mentioned include vinblastine analogues, indoles, Benzofuran 12, compound 12, benzofuran 13, compounds 13 and 14, compounds 15 and 27, the second diastereomer of compound 15, compound 16, compound 17, and compounds 18 and 19. The documents provide detailed procedures for the synthesis of these compounds, as well as information about their physical properties and spectroscopic data. The information presented can be useful for researchers studying these compounds and their properties. [Extracted from the article]

This manuscript presents a regioselective chlorination of arenes, yielding almost exclusively the monochlorinated product. It tolerates free hydroxy groups, 1°, 2° and 3° amines, and carboxylic acids, among other polar and nonpolar functional groups, as well as mono‐ and polysubstituted aromatic rings. Additionally, the utilization of chlorosulfonium salts as the chlorinating agent is demonstrated. The method emerges as an alternative to other processes where organic byproducts must be separated from the reaction mixture. In addition, the main byproducts are gaseous materials such as CO and CO2. This publication introduces the application of sulfoxides, oxalyl chloride, and aqueous hydrogen peroxide as the chlorination mixture. [ABSTRACT FROM AUTHOR]

Cyclic [3]spirobifluorenylene with bulky alkyl groups at the ends (1) was designed and synthesized to investigate the electron transfer phenomena in a π‐conjugated system including orthogonal π‐conjugated chains. The three bifluorenyl units in 1 are conjugated to each other via spiro‐conjugation, resulting in the splitting of the HOMO levels to a small extent. Therefore, the SOMO‐HOMO gap of the radical cation species is small, which is considered to allow the facile intramolecular electron transfer. The electronic properties of 1 and its partial structures were characterized by absorption and fluorescence measurements and electrochemical analysis. From the electrochemical oxidation, the interchain Coulombic repulsion was observed. In the TD‐DFT calculations for the radical cation species of 1, the geometry‐featured interchain electronic transitions were visualized by NTO calculations. The radical cation species of 1 generated by chemical oxidation with SbCl5 exhibited a broadened and lower‐energy NIR absorption band exceeding 2000 nm. Considering the results of the TD‐DFT calculations, the NIR band of the radical cation of 1 was attributed to the intramolecular electron transfer processes among the bifluorenyl units in the macrocycle. ESR experiments also indicated the delocalization of a spin of 1⋅+ in the whole molecule via hole hopping in the ESR time scale at room temperature. This work demonstrates the usefulness of spiro‐conjugation as a bridging unit in molecular wires to facilitate smooth electron transfer. [ABSTRACT FROM AUTHOR]

The catalytic C−H borylation of (hetero)arenes involving borenium species has witnessed fast development in the past decade. This review aims at summarize recent progress made in this field, with an emphasis on synthetic application and reaction mechanisms. [ABSTRACT FROM AUTHOR]

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures. For the liquid-phase hydrodeoxygenation (HDO) based on metallic catalysts, the preservation of aromatic rings in lignin or its derivatives remains a challenge. Herein, we synthesized Mn-doped Cu/Al2O3 catalysts from layered double hydroxides (LDHs) for liquid-phase HDO of lignin-derived anisole. Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al2O3. With Mn doping increasing, the surface of Cu particles was modified with MnOx along with enhanced generation of oxygen vacancies (Ov). The evolution of active sites structure led to a controllable adsorption geometry of anisole, which was beneficial for increasing arenes selectivity. As a result, the arenes selectivity obtained on 4Cu/8Mn4AlOx was increased to be more than 6 folds of that value on 4Cu/4Al2O3 over the synergistic sites between metal Cu and Ov generated on MnOx.

[Display omitted] Conversion of isobutyl alcohol over the HMFI/SiC composite has been for the first time studied. Isobutanol (bioisobutanol) considered as a promising product of biomass processing was catalytically converted into aromatic hydrocarbons of the benzene–toluene–xylene fraction (BTX) and olefins C 2 –C 4 (mainly propylene and butenes). Compared with the pure zeolite, the incorporation of HMFI into the SiC matrix enhanced the yields of C 2 –C 4 olefins and BTX in the isobutanol conversion due to increased densities of Brønsted and Lewis acid centers [ABSTRACT FROM AUTHOR]

Fluorinated compounds have attracted attention in both the pharmaceutical industry and materials science due to the small size and strong electron-withdrawing property of the fluorine atom. In materials science, perfluorinated polyphenylenes play an important role as electron transport layers in organic electronics. While various strategies for the preparation of fluorinated arenes have been reported, the number of synthetic methods available for perfluorinated arenes remains limited, mainly due to the change in reactivity of reagents and substrates at the reaction site upon the introduction of additional fluorine atoms. Given the important applications of perfluorinated polyphenyl-based compounds, this article describes the one-step synthesis of the dendrimer perfluoro-3,3'5,5'-tetrakisphenyldiphenyl-1,1', which to date no example of a targeted synthesis has been reported in literature, and the synthetic methodology for the direct preparation of linear perfluorinated para-sexiphenyl. Both strategies use starting materials that are either commercially available or can be easily accessed using standard literature methods. [ABSTRACT FROM AUTHOR]

Corannulene, a curved polycyclic aromatic hydrocarbon, is prepared in a multigram scale through mechanochemical synthesis. Initially, a mixer mill approach is examined and found to be suitable for a gram scale synthesis. For larger scales, planetary mills are used. For instance, 15 g of corannulene could be obtained in a single milling cycle with an isolated yield of 90 %. The yields are lower when the jar rotation rate is lower or higher than 400 revolutions per minute (rpm). Cumulatively, 98 g of corannulene is produced through the ball milling‐based grinding techniques. These results indicate the future potential of mechanochemistry in the rational chemical synthesis of highly curved nanocarbons such as fullerenes and carbon nanotubes. [ABSTRACT FROM AUTHOR]

This article presents two groups of V‐shaped π‐scaffolds that consist of two N‐heteroacene units fused with either a rigid or flexible eight‐membered ring. These rigid and flexible N‐heteroacene dimers were synthesized through the condensation of tetraphenylenetetraone with the corresponding diamine and the Pd‐catalyzed cross‐coupling of tetrabromodibenzo[a,e]cyclooctatetraene with the corresponding diamine, respectively. A comparison of electronic structures and properties of the two groups of V‐shaped N‐heteroacene dimers shows subtle difference between the rigid and flexible eight‐membered ring linkers in forming extended π‐systems. X‐ray crystallography of these V‐shaped molecules has revealed interesting π‐π interaction modes, which are dependent on the central connecting units and substituting groups. These π‐π interactions between the V‐shaped π‐scaffolds have enabled the molecules to function as organic semiconductors in solution‐processed field effect transistors. [ABSTRACT FROM AUTHOR]

The Newman Kwart Rearrangement (NKR) offers an efficient and high‐yielding method for producing substituted thiophenols from phenols. While an industrially important protocol, it suffers from high activation energy barriers (35–43 kcal/mol), requiring the use of extreme temperatures (>200 °C) and specialty equipment. This report details a highly efficient and straightforward method for facilitating the NKR using photothermal conversion. This underused, unique reactivity pathway arises from the irradiation of nanomaterials that relax via a non‐radiative decay pathway to generate intense thermal gradients. We show carbon black (CB) can be an inexpensive and abundant photothermal agent under visible light irradiation to achieve a facile NKR under mild conditions. The scope includes a wide array of stereo‐ and electronically diverse substrates with increasing difficulty of rearrangement, including BHT and BINOL as effective substrates. Furthermore, we demonstrate the unique application for temporal control in a thermal reaction and tunability of thermal gradients by modulating light intensity. Ultimately, photothermal conversion enables high‐temperature reactions with simple, visible light irradiation. [ABSTRACT FROM AUTHOR]

The utilization of DMSO or Ph2SO/(COBr)2 or (COCl)2 for the bromination or chlorination of arenes has been explored. Notably, monobromination of activated arenes can be achieved with high regioselectivity using the combination of dimethyl sulfoxide and oxalyl bromide. Bromodimethylsulfonium bromide generated in situ was proposed to be the active species for bromination. In contrast, the practicality of chlorination of arenes with DMSO or Ph2SO/(COCl)2 is limited due to production of the formation of by-products such as aryldimethylsulfonium chlorides or dichlorinated arenes. [ABSTRACT FROM AUTHOR]

Urease is an important virulence factor involved in the colonization and infection of gastric mucosa by Helicobacter pylori. In this work, the urease inhibitory activity of a series of γ-alkylidenebutenolides analogues of natural rubrolides is presented. The compounds were prepared from a commercial 3,4-dibromofuran-(5H)-2-one, as previously reported, including three new derivatives. The rubrolide analogues (at 500 µM) showed percentages of urease inhibition ranging from 20.7 to 99.3%. The most active compounds (IC50 from 111.5 to 306.0 µM) were shown to be more potent than hydroxyurea (IC50 844.4 µM), a standard urease inhibitor. Rubrolide analogues with phenolic hydroxyl groups revealed higher potency compared with other substances evaluated. Their physicochemical parameters (partition coefficient, molecular weight, hydrogen bonding acceptors, number of hydrogen bonding donor groups, number of rotatable bonds, and the number of aromatic bonds) related to general pharmacokinetic requirements showed drug-like properties for the evaluated rubrolide analogues. Docking studies suggest that the presence of hydroxy groups at the ortho position favors both the formation of reversible interactions with urease and the formation of a covalent adduct with the active site causing blocking of the enzyme, like what happens with catechol, its natural inhibitor. The high biological activity herein reported indicates that rubrolides constitute promising leads for the development of a new class of urease inhibitor drugs. [ABSTRACT FROM AUTHOR]

Fragments of buckminsterfullerene (C60) include the monumental three compounds corannulene, sumanene, and truxene. These three have served as leading molecules in ongoing research for curved, fused, and π‐extended polyaromatic materials. Achieving more structural variations that join the ranks of these three archetypes remains challenging. Herein we report synthesis of an octacyclic hydrocarbon that is an unexplored C60‐fragment, namely, a 4,11‐dihydrodiindeno[7,1,2‐ghi:7′,1′,2′‐pqr]chrysene (C28H16, which we named Metelykene). The key to success was solution‐compatible synthesis in which double pentagonal rings flank hexagonal ones. This solution‐phase approach, coupled with the resulting non‐planar π‐conjugation, is so straightforward that it offers an entry to a derivative such as a cardo aromatic monomer. [ABSTRACT FROM AUTHOR]

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure. Herein, we synthesized a series of novel Cu-based catalysts, Cu@NS-SiO2 (NS ¼ nano sphere) and alkali metals (Na, K, Rb, and Cs) doped Cu@NS-SiO2, and applied them in hydrodeoxygenation reaction of anisole. High Cu dispersion was presented on all catalysts. The modification of alkali metals on Cu@NS-SiO2 significantly enhanced the electron density of Cu sites in the following order: Cs > Rb > K > Na, among which Cs decreased the Cu 2p3/2 binding energy most (by 0.7 eV). Moreover, the modification did not substantially affect the geometric structure of Cu species. This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole, and thus promoted the selectivity of benzene. Compared with Cu@NS-SiO2 (~59%), the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO2 at ~83%. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The direct use of non‐prefunctionalized arene and alkane as the starting materials to construct Caryl−Calkyl bond is an unfulfilled target and approaches to this challenge rarely surface in methodology studies. Current methods for thermocatalytic arene‐alkane couplings (AAC) occur with specific substrates and/or inconvenient reagents. Herein, we report a one‐pot relay bicatalysis system for AAC involving (pincer)Ir‐catalyzed alkane transfer dehydrogenation and Fe(OTf)3‐catalyzed olefin hydroarylation. This system exhibits broad scope and is particularly effective for alkylation of arenes with arylalkanes to form 1,1‐diarylalkanes with high chemo‐ and regioselectivity, making it potentially useful for late‐stage alkylation of complex molecules. Experimental mechanistic data provide a view into the factors controlling the regioselectivity. Finally, the strategy of dehydrogenation‐enabled arene‐alkane couplings has been successfully extended to a tandem catalysis by using a heterogeneous olefin hydroarylation catalyst. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The direct use of non‐prefunctionalized arene and alkane as the starting materials to construct Caryl−Calkyl bond is an unfulfilled target and approaches to this challenge rarely surface in methodology studies. Current methods for thermocatalytic arene‐alkane couplings (AAC) occur with specific substrates and/or inconvenient reagents. Herein, we report a one‐pot relay bicatalysis system for AAC involving (pincer)Ir‐catalyzed alkane transfer dehydrogenation and Fe(OTf)3‐catalyzed olefin hydroarylation. This system exhibits broad scope and is particularly effective for alkylation of arenes with arylalkanes to form 1,1‐diarylalkanes with high chemo‐ and regioselectivity, making it potentially useful for late‐stage alkylation of complex molecules. Experimental mechanistic data provide a view into the factors controlling the regioselectivity. Finally, the strategy of dehydrogenation‐enabled arene‐alkane couplings has been successfully extended to a tandem catalysis by using a heterogeneous olefin hydroarylation catalyst. [ABSTRACT FROM AUTHOR]

Herein, we report the design of meso‐aryl BODIPYs as a structural motif for aggregation‐caused quenching (ACQ) to aggregation‐induced emission (AIE) transformation. A series of meso‐aryl BODIPY derivatives were synthesized, by systematically increasing the size of the chromophore at the meso‐position from phenyl to pyrene. The effect of various factors, such as the aryl ring size, solvents, viscosity, and metal cations, on the photophysical properties was analyzed. The emission properties are well correlated with the flexibility of the aromatic ring for free rotation around the Caryl−CBODIPY bond. Accordingly, meso‐phenanthrene BODIPY (PhB) has the highest emission characteristics. The emission property of less bulky aryl‐substituted BODIPYs increases by increasing the solvent viscosity. The interaction of Fe3+ ions with aryl‐BODIPYs provides a prominent photophysical response based on Lewis‐acid supported decomplexation of BF2 in aryl‐BODIPYs. The bichromophoric meso‐aryl BODIPYs exhibit notable intramolecular excitation energy transfer from the aromatic ring to the BODIPY core, which is higher in meso‐anthracene BODIPY(AB). Hence, decorating BODIPYs with polycyclic aromatic systems generates a twisted structure, which inhibits the π‐π stacking between the planar aromatic molecules. This can be proposed as an effective approach at the molecular level to convert planar aryl luminophores having ACQ to AIEgens. Besides, the meso‐pyrene BODIPY derivative shows excellent mechanofluorochromic behaviour. [ABSTRACT FROM AUTHOR]

New molecular scaffolds of C‐, Z‐ and box‐shaped configurations are constructed by fusing phenazine and pyrene units with oxanorbornene. As revealed by X‐ray crystallography, the C‐shaped molecules exhibit two interesting π‐π stacking modes of phenazine depending on the substituting groups, and the box‐shaped molecule accommodates two chloroform molecules in the cavity and forms H‐bonds with another four molecules of chloroform. The C‐ and Z‐shaped molecules as a pair of diastereomers exhibit almost the same charge transfer absorption and emission including positive solvatochromism, indicating that the intramolecular charge transfer between pyrene (π‐donor) and phenazine (π‐acceptor) is not dependent on the overall molecular geometry. [ABSTRACT FROM AUTHOR]

Herein, we report the redox reactivity of a multimetallic uranium complex supported by triphenylsiloxide (−OSiPh3) ligands, where we show that low valent synthons can be stabilized via an unprecedented mechanism involving intramolecular ligand migration. The two‐ and three‐electron reduction of the oxo‐bridged diuranium(IV) complex [{(Ph3SiO)3(DME)U}2(μ‐O)], 4, yields the formal "UII/UIV", 5, and "UI/UIV", 6, complexes via ligand migration and formation of uranium‐arene δ‐bond interactions. Remarkably, complex 5 effects the two‐electron reductive coupling of pyridine affording complex 7, which demonstrates that the electron‐transfer is accompanied by ligand migration, restoring the original ligand arrangement found in 4. This work provides a new method for controlling the redox reactivity in molecular complexes of unstable, low‐valent metal centers, and can lead to the further development of f‐elements redox reactivity. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) hydrogenolysis can produce benzene, toluene, and xylene (BTX), where the selectivity control is challenging. We report a reaction pathway dictated by the Ru coordination environment by examining the binding geometries of adsorbates on differently coordinated Ru centers and their evolution during PET hydrogenolysis. A BTX yield of 77 % was obtained using a Ru/TiO2 with a Ru coordination number of ca. 5.0 where edge/corner sites are dominant, while more gas and saturated products were formed for Ru/TiO2 containing primarily terrace sites. Density functional theory and isotopic labelling revealed that under‐coordinated Ru edge sites favor "upright" adsorption of aromatic adsorbates while well‐coordinated Ru sites favor "flat‐lying" adsorption, where the former mitigates ring hydrogenation and opening. This study demonstrates that reaction pathways can be directed through controlled reactant/intermediate binding via tuning of the Ru coordination environment for efficient conversion of PET to BTX. [ABSTRACT FROM AUTHOR]

A mild and efficient copper‐mediated trifluoromethylation of diaryliodonium salts with readily available fluoroform has been developed. The reaction exhibits excellent functional group tolerance, affording trifluoromethylated arenes in good yields. This approach provides a straightforward incorporation of CF3 group into complex molecules for drug discovery. [ABSTRACT FROM AUTHOR]

Deuterium(D)‐labeled aromatics play an essential part in the Yield of fine chemicals. However, deuteration reactions are particularly dependent on the specific chemical environment of the metal to finish the oxidative addition and reductive elimination. Herein, a complex valence Pt/Ca12Al14Ox catalyst was successfully synthesized for the deuteration of toluene using inexpensive D2O. It exhibited high deuteration efficiency, achieving 96% deuteration in just 4 hours, 14% higher than the most commonly Pt/C catalyst. The catalyst can also be reactivated and recycled up to 16 times. Multiple characterization techniques were used to demonstrate the interaction between Pt and Ca12Al14Ox generates the co‐existence of Pt(δ+) and Pt(0). The synergy between Pt(δ+) and Pt(0) can promote the completion of oxidation and elimination reactions. Thus, the complex valence of Pt improves the processes required for H−D exchange and boosts the reaction rate and stability of the hydrogen isotope exchange system. [ABSTRACT FROM AUTHOR]

Herein we show that hybridisation of buckybowl corannulene and thiophene‐S,S‐dioxide motifs is a general approach for the preparation of high electron affinity molecular materials. The devised synthesis is modular and relies on thienannulation of corannnulene‐based phenylacetylene scaffolds. The final compounds are highly soluble in common organic solvents. These compounds also exhibit interesting optical properties such as absorption and emission in the blue/green regions of the electromagnetic spectrum. Importantly, a bis‐S,S‐dioxide derivative exhibits three reversible reductions similar in their strength to the prevalent fullerene‐based electron acceptor phenyl‐C61‐butyric acid methyl ester (PC61BM). [ABSTRACT FROM AUTHOR]

Fluoroarenes are abundant and readily available feedstocks. However, due to the high reduction potentials of mono‐fluoroarenes, their photoreduction remains a continuing challenge, motivating the development of efficient activation modes to address this issue. This report presents the blue light‐induced N‐heterocyclic carbene (NHC)‐catalyzed single electron reduction of mono‐fluoroarenes for biaryl cross‐couplings. We discovered that under blue light irradiation, NHC/tBuOK combination could construct powerful photoactive architectures to promote single electron transfer for Caryl−F bond reduction via forming highly reducing NHC radical anion. Notably, the strategy was also successful to reduce Caryl−O, Caryl−N, and Caryl−S bonds for biaryl cross‐couplings. [ABSTRACT FROM AUTHOR]

Combination of Karstedt's catalyst or Pt(dba)2 [dba: dibenzylideneacetone] with activated carbon was found to be an efficient catalyst system for the arene hydrogenation of a variety of functionalized aromatic compounds. The reaction proceeds at ambient temperature under atmospheric hydrogen pressure to afford the corresponding carbo‐ and heterocyclic compounds in good to high yields without contamination of the metallic species. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the platinum species effectively after the reaction. Similar sustaining effect was observed by the addition of vinyl siloxane derivatives. [ABSTRACT FROM AUTHOR]

Microporous zeolites are commonly employed as catalysts for the benzylation of arenes and benzyl alcohol. However, their catalytic efficiency is often compromised by diffusion limitations, particularly in reactions involving larger arenes. In this study, we developed metal-ion modified HY zeolites using Zn, Mg, and Ni as dopants and investigated their catalytic performance in the benzylation of a range of arenes, including toluene, benzene, mesitylene, p-xylene and with benzyl alcohol (BzOH). The structural and acidic properties of the modified HY zeolites were characterized using a combination of techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), N₂ adsorption–desorption isotherms, Fourier-transform infrared (FTIR) spectroscopy, ammonia temperature-programmed desorption (NH₃-TPD), and proton magic angle spinning nuclear magnetic resonance (1H MAS NMR) spectroscopy. The presence of catalytically active Brønsted acid sites (BAS) was detected by 1H MAS NMR spectroscopy and it was demonstrated that the HY zeolite's acidity is considerably modulated by the addition of metal ions. The catalytic evaluations indicated that the metal-ion modified HY zeolites exhibited superior activity compared to unmodified HY zeolite, with the catalytic performance following the order Zn/HY > Ni/HY > Mg/HY > HY for the benzylation of benzyl alcohol with mesitylene. Further investigation into the mechanism revealed that the synergistic effect of metal ions and acidity plays a crucial role in enhancing the accessibility of arenes to the surface catalytic sites and thereby improving catalytic performance. These findings underscore the importance of the metal-acidity synergy in optimizing the catalytic efficacy of modified HY zeolites for selective benzylation reactions. [Display omitted] • Metal-ion modified HY zeolites were developed with Zn, Mg, and Ni as dopants. • HY zeolites were characterized using SEM, XRD, and N₂ adsorption–desorption isotherms. • These modified zeolites were tested for catalytic performance in the benzylation of arenes like toluene, benzene and mesitylene • Zn/HY showed the highest catalytic activity, followed by Ni/HY, Mg/HY and unmodified HY. [ABSTRACT FROM AUTHOR]

Treatment of phosphino(imino)pyridine (PIP) molybdenum cyclooctadiene (COD) complexes [(PIP)Mo(COD)] with dihydrogen in the presence of benzene selectively furnished the molybdenum cyclohexadienyl hydrides [(PIP)MoH(η5‐C6H7)], which are precatalysts for the hydrogenation of benzene to cyclohexane. [(PIP)MoH(η5‐C6H7)] arises from a rarely observed insertion of benzene into a molybdenum‐hydride bond, a key step in the molybdenum‐catalyzed homogeneous hydrogenation of arenes. The reaction with toluene afforded a single isomer of the corresponding molybdenum cyclohexadienyl hydride while para‐xylene predominantly formed the molybdenum η6‐arene complex with the insertion product being a minor component. Addition of carbon monoxide to a cyclohexane‐d12 solution of [(PIP)MoH(η5‐C6H7)] liberated cyclohexadiene, providing experimental support for a higher kinetic barrier for the subsequent steps en route to cycloalkanes. [ABSTRACT FROM AUTHOR]

Versatile fluorescent polyaromatic compounds of alternating benzene and furan rings, para - and meta -bis(5-phenylfur-3-yl)benzenes, were expeditiously synthesized by double Mn(OAc)3-catalyzed oxidative decarbonylation and Paal–Knorr reactions of β-ketoesters, prepared from the conjugate addition of ethyl acetoacetate to para - and meta -bis(chalcones). Stronger fluorescence intensity was observed for meta -bis(phenylfuryl)benzene with ortho -methoxy substitution, whereas longer fluorescence wavelength was observed for para -bis(phenylfuryl)benzene with para -methoxy substitution. [ABSTRACT FROM AUTHOR]

Fluorine-containing functional groups are important motifs influencing physical and biological properties of organic compounds. Visible-light photoredox catalysis as a powerful strategy for the activation of small molecules contributed significantly to the rapid progress of new synthetic procedures allowing introduction of fluorine atoms into organic substrates. In this review, we highlight the distinct strategies for transition metal- and organic-photocatalytic fluorination of arenes and heteroarenes by a broad range of fluorinating compounds. The presented procedures are divided into two groups. The first group involves the reactions enabling a direct attachment of CF3-, CnFm-, F-, CF3O-, CF3S-, and SO2F- substituents to various aromatic compounds. The second group presents the tandem reactions where the formation of the aromatic system occurs after installation of the fluorine-containing group on the non-aromatic fragment of the molecule. [ABSTRACT FROM AUTHOR]