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exo‐6b2‐Methyl‐substituted pentabenzocorannulene (exo‐PBC‐Me) was synthesized by the palladium‐catalyzed cyclization of 1,2,3‐triaryl‐1H‐cyclopenta[l]phenanthrene. Its bowl‐shaped geometry with an sp3 carbon atom in the backbone and a methyl group located at the convex (exo) face was verified by X‐ray crystallography. According to DFT calculations, the observed conformer is energetically more favorable than the endo one by 39.9 kcal/mol. Compared to the nitrogen‐doped analogs with intact π‐conjugated backbones (see the main text), exo‐PBC‐Me displayed a deeper bowl depth (avg. 1.93 Å), redshifted and broader absorption (250–620 nm) and emission (from 585 to more than 850 nm) bands and a smaller optical HOMO–LUMO gap (2.01 eV). exo‐PBC‐Me formed polar crystals where all bowl‐in‐bowl stacking with close π ⋅ ⋅ ⋅ π contacts is arranged unidirectionally, providing the potential for applications as organic semiconductors and pyroelectric materials. This unusual structural feature, molecular packing, and properties are most likely associated with the assistance of the methyl group and the sp3 carbon atom in the backbone. [ABSTRACT FROM AUTHOR]

In X‐ray structures of the isomorphic mer‐[IrX3(THT)(CNXyl)2] (X=Cl 1, Br 2; THT=tetrahydrothiophene; Xyl=2,6‐Me2C6H3−) complexes, we revealed short intermolecular contacts between the C‐atom of an isocyanide methyl group and halide ligands of another molecule. Geometrical consideration of the X‐ray data and analysis of appropriate DFT studies allowed the attribution of these contacts to CMe⋅⋅⋅X−IrIII (X=Cl, Br) tetrel bond. Specifically, through the application of DFT calculations and various theoretical models, the presence of tetrel bonding interactions was validated, and the contribution of the CMe⋅⋅⋅X−IrIII interaction was assessed. The reinforcement of the tetrel bond upon the isocyanide coordination to iridium(III) is substantiated by molecular electrostatic potential (MEP) surface calculations. To distinguish the tetrel bonding characteristics of CMe⋅⋅⋅X−IrIII (X=Cl, Br) interactions from conventional hydrogen bonding, we employed multiple computational methodologies, including Natural Bond Orbital (NBO) analysis and Electron Localization Function (ELF) analysis. Additionally, Energy Decomposition Analysis (EDA) was applied to selected model systems to explore the underlying physical nature of these interactions. [ABSTRACT FROM AUTHOR]

Functionalization of Si‐bound methyl group provides an efficient access to diverse organosilanes. However, the asymmetric construction of silicon‐stereogenic architectures by functionalization of Si‐bound methyl group has not yet been described despite recent significant progress in producing chiral silicon. Herein, we disclosed the enantioselective silylmethyl functionalization involving the aryl to alkyl 1,5‐palladium migration to access diverse naphthalenes possessing an enantioenriched stereogenic silicon center, which are inaccessible before. It is worthy to note that the realization of asymmetric induction at the step of metal migration itself remains challenging. Our study constitutes the first enantioselective aryl to alkyl 1,5‐palladium migration reaction. The key to the success is the discovery and fine‐tuning of the different substituents of α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol (TADDOL)‐based phosphoramidites, which ensure the enantioselectivity and desired reactivity. [ABSTRACT FROM AUTHOR]

Tetra‐cyano substituted naphthalene diimides (TCNDIs) with calculated LUMO of −5.2 eV, form one of the strongest electron‐acceptors known to date. However, the synthesis and isolation of this class of molecules remain challenging due to its reactivity emanating from its ultra‐electron‐deficiency. Herein we have established an improved synthetic methodology of TCNDIs with cost‐effective reagents and circumventing metallic catalysts. The synthesis is amenable to TCNDIs with the shortest axial alkyl groups, i. e. methyl group and also longer alkyl chains. We also gained insight on how axial alkyl chain lengths influence electron‐deficiency, Meisenheimer complex formation, reactivity, and charge‐transfer of TCNDIs from computation, spectroscopy, and electrochemical studies. The TCNDIs with Me/Et axial groups were found to be more susceptible to moist solvents vis‐à‐vis the TCNDIs with longer alkyl groups. The single crystal structures of the TCNDIs show infinitely π‐stacked structure, and a new C=O ⋅ ⋅ ⋅ C≡N or C≡N ⋅ ⋅ ⋅ π motif is discerned. Finally, toluene‐mediated charge‐transfer properties of TCNDIs in the single crystals as well as in solution have been examined. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate an Oxa‐Diels‐Alder reaction of 3‐trifluoroacetyl‐4‐methyl‐quinolin‐2(1H)‐one with aldehydes in the presence of a base to engineer the functionalized pyrano[3,4‐c]quinolones. This reaction proceeds through an in‐situ generated hetero dendralene intermediate and features perfect stereoselectivity on a wide range of substrates with excellent atom economy. The high electron‐withdrawing nature of CF3‐group is responsible for making the methyl group present in quinolone moiety more acidic to furnish the corresponding hetero dendralene intermediate. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Photoinitiators of the oxime ester (OXE) or ketoxime ester (OXE‐CO) type can rapidly undergo N—O bond cleavage and generate free radicals to initiate photopolymerization under LED excitation, occupying an important position in the field of photocuring. However, the commercial OXEs, e.g., OXE 01 and 02 with λmax's at 326 and 344 nm, respectively, still do not well match the emission spectra of LEDs. Developing novel OXEs/OXE‐COs with high photosensitivity for long‐wavelength LEDs has great significance. Here, four new OXEs/OXE‐COs with nitro‐carbazole‐styrene conjugated chromophore were designed, synthesized, and used as photoinitiators. Results demonstrated that all photoinitiators had strong absorption within the UV–vis range (λmax: 381—392 nm, εmax: 8200—11500 M−1·cm−1). Molecular design of the oxime ester cleavage to produce a small volume methyl group and a methacryl group with an unsaturated double bond brings high activity and low migration, respectively, in one‐photon polymerization under 365—450 nm LEDs excitation. Moreover, OXEs/OXE‐COs with PETA exhibited a wide processing window, high resolution (line accuracy~100 nm) and good nano‐patterning capability under 780 nm femtosecond laser irradiation in two‐photon polymerization, indicating their great potential in 2D/3D microfabrication technologies. [ABSTRACT FROM AUTHOR]

This study investigates polyaniline (PANI) for its sensing characteristics for detecting acetaldehyde. Pristine PANI is further modified in two ways to improve its sensing capabilities: 1) addition of a side chain (i.e., two methyl groups) to form poly (2,5‐dimethylaniline), 2) addition of small amounts of metal oxide dopant (In2O3 in this case) to PANI. All the materials are evaluated for their sensing characteristics with respect to both sensitivity and selectivity. The sensitivity of PANI toward acetaldehyde is found to improve with both types of modification (i.e., poly (2,5‐dimethylaniline) and PANI doped with different wt.% of In2O3). However, upon evaluating selectivity toward acetaldehyde using binary and ternary gas mixtures, pristine PANI exhibited higher selectivity compared to its modified counterparts. [ABSTRACT FROM AUTHOR]

First case of regiospecific formation of indole fused with a triterpene scaffold is observed. Starting from 3‐oxo‐24‐nor‐allobetulin Fischer reaction with phenylhydrazine under the influence of weak acid catalyst led to 3H‐indole (indolenine) 4. This process was accompanied by a change in the configuration of the methyl group at C‐4 that was confirmed by x‐ray diffraction method. On the other hand, 3,2‐indole 5 was synthesized under the influence of strong acid catalyst (using phenylhydrazine hydrochloride in AcOH acid or phenylhydrazine in MeOH with a few drops of HCl). [ABSTRACT FROM AUTHOR]

The histone deacetylases (HDACs) are being explored as a promising therapeutic target for the treatment of various diseases. Here, the synthesis of a series of pyrimidine‐based 1,3,4‐oxadiazoles, in which the oxadiazole scaffold is attached to the pyrimidine ring via a methyleneoxy spacer, is described and their HDAC inhibitory activity studied. The target compounds were synthesized by sequence of reactions involving O‐alkylation of 2‐(methylthio)pyrimidin‐4(3H)‐ones with ethyl 2‐bromoethanoate followed by oxidation of the 2‐methylthio group, displacement of the obtained 2‐methylsulfonyl group with amines, hydrazinolysis of the obtained ethyl (2‐amino‐substituted pyrimidin‐4‐yloxy)acetates to give the corresponding hydrazides and their cyclization under the treatment with ethyl O‐ethyl xanthate or carbonyldiimidazole to 1,3,4‐oxadiazole‐2(3H)‐thiones and 1,3,4‐oxadiazol‐2(3H)‐one, correspondingly. In addition, two 1,3,4‐oxadiazole‐2(3H)‐thiones were converted into (N3)‐morpholinomethyl derivatives by the Mannich reaction with formaldehyde and morpholine. The yields of intermediates and target compounds ranged from moderate to excellent. The synthesized compounds were characterized by 1H and 13C NMR spectra and HRMS data, their purity was controlled by TLC. The synthesized pyrimidine‐based 1,3,4‐oxadiazoles (18 compounds) were tested as inhibitors of the HDAC4 and HDAC8 isoforms and their inhibitory activity was compared with that of Vorinostat. Most of the oxadiazolethiones containing methyl group at the position 6 of the pyrimidine moiety were found to be more selective towards HDAC8, while oxadiazolethiones with propyl group in the pyrimidine ring were active against HDAC4. Among the tested compounds, 5‐((2‐(dibutylamino)‐6‐propylpyrimidin‐4‐yloxy)methyl)‐1,3,4‐oxadiazole‐2(3H)‐thione (48) was found to have the strongest inhibitory activity for HDAC4 isoform (IC50 = 4.2 μM vs. IC50 = 59 μM for Vorinostat) while 5‐((2‐(cyclopentylamino)‐6‐propylpyrimidin‐4‐yloxy)methyl)‐1,3,4‐oxadiazole‐2(3H)‐thione (50) was the most potent HDAC8 inhibitor (IC50 = 6.8 μM). [ABSTRACT FROM AUTHOR]

Genomic DNA methylation patterns play a crucial role in the developmental processes of plants and mammals. In this study, we aimed to investigate the significant effects of epigenetic mechanisms on the development of soybean seedlings and metabolic pathways. Our analyses show that 5‐azaC‐treatment affects radicle development from two Days After Imbibition (DAI), as well as both shoot and root development. We examined the expression levels of key genes related to DNA methylation and demethylation pathways, such as DRM2, which encodes RNA‐directed DNA Methylation (RdDM) pathway, SAM synthase, responsible for methyl group donation, and ROS1, a DNA demethylase. In treated seedling roots, we observed an increase in DRM2 expression and a decrease in ROS1 expression. Additionally, 5‐azaC treatment altered protein accumulation, indicating epigenetic control over stress response while inhibiting nitrogen assimilation, urea cycle, and glycolysis‐related proteins. Furthermore, it influenced the levels of various phytohormones and metabolites crucial for seedling growth, such as ABA, IAA, ethylene, polyamines (PUT and Cad), and free amino acids, suggesting that epigenetic changes may shape soybean responses to pathogens, abiotic stress, and nutrient absorption. Our results assist in understanding how hypomethylation shapes soybean responses to pathogens, abiotic stress, and nutrient absorption crucial for seedling growth, suggesting that the plant's assimilation of carbon and nitrogen, along with hormone pathways, may be influenced by epigenetic changes. [ABSTRACT FROM AUTHOR]

Chalcogen bonds (ChB) are moderately strong, directional, and specific non‐covalent interactions that have garnered substantial interest over the last decades. Specifically, the presence of two σ‐holes offers great potential for crystal engineering, catalysis, biochemistry, and molecular sensing. However, ChB applications are currently hampered by a lack of methods to characterize and control chalcogen bonds. Here, we report on the influence of various substituents (halogens, cyano, and methyl groups) on the observed self‐complementary ChB networks of 2,1,3‐benzoselenadiazoles. From molecular electrostatic potential calculations, we show that the electrostatic surface potentials (ESP) of the σ‐holes on selenium are largely influenced by the electron‐withdrawing character of these substituents. Structural analyses via X‐ray diffraction reveal a variety of ChB geometries and binding modes that are rationalized via the computed ESP maps, although the structure of 5,6‐dimethyl‐2,1,3‐benzoselenadiazole also demonstrates the influence of steric interactions. 77Se solid‐state magic‐angle spinning NMR spectroscopy, in particular the analysis of the selenium chemical shift tensors, is found to be an effective probe able to characterize both structural and electrostatic features of these self‐complementary ChB systems. We find a positive correlation between the value of the ESP maxima at the σ‐holes and the experimentally measured 77Se isotropic chemical shift, while the skew of the chemical shift tensor is established as a metric which is reflective of the ChB binding motif. [ABSTRACT FROM AUTHOR]

The molecular structure of a crystalline monolayer of hydrocarbon chains was modeled and studied via computer simulation using the Metropolis Monte Carlo algorithm at a temperature T = 300 K. The only interactions in this system occur through Lennard‐Jones dispersion forces and short‐range atom‐atom repulsion. The intent was to establish whether the chains were either rigidly extended or twisted via the thermal formation of gauche bonds and apply the results to understand observations made on two possible oleogelators: triacontane and stearic acid. Specifically, we aimed to understand if their observed crystalline monolayer thicknesses are due to gauche‐bond‐shortened hydrocarbon chains oriented perpendicular to the monolayer surface, or to fully extended rigid chains oriented at a tilt angle with respect to the surface. The results showed that crystals of hydrocarbon chains did not include significant gauche bonds, so that all molecules were rigidly extended, thus explaining the experimental data previously reported. Accordingly, TC and SA dimer molecules are packed in crystalline multilayers with tilt angles in relation to the methyl group plane. [ABSTRACT FROM AUTHOR]

A series of novel 2‐(2‐pyridyl)quinazoline luminophores containing a donor aryl fragment at position 4 and methyl or methoxy groups at benzene ring has been synthesized by efficient three‐step route. The linear optical properties have been studied by UV/Vis absorption and photoluminescence spectra in two solvents. We revealed that introduction of additional methyl group or the replacement of methyl substituents with methoxy ones lead to sequentially shift of absorption and emission maximum to blue region. 9H‐Carbazol‐9‐yl‐containing derivative is characterized by hypsochromically shifted absorption band compared to its NEt2 and NPh2 counterparts. Unlike 9H‐carbazol‐9‐yl‐derivative, Et2N‐ and Ph2N‐bearing quinazolines demonstrate considerable decrease in quantum yield values when going from toluene to MeCN. Solvatochromic properties have been explored, the pronounced bathochromic shift was observed in fluorescence spectra with the increase of solvents polarity. Moreover, the compounds show significant shift of emission band with the increase of water fraction in DMSO/H2O mixture. Two‐photon optical properties have been also studied, the two‐photon absorption cross‐sections in MeCN and toluene reached 120 GM and 210 GM, respectively. The presence of additional methyl group has little impact on δTPA value, while introduction of methoxy substituents dramatically decreases TPA cross sections. Additionally, a quantum‐chemical calculations of synthesized compounds were performed to support the experimental data. [ABSTRACT FROM AUTHOR]

This study employs grand canonical Monte Carlo (GCMC) simulations to investigate the impact of functional group modifications (CH3, OH, NH2, and OLi) on the adsorption performance of CH4/N2 on Ni‐MOF‐74. The results revealed that functional group modifications significantly increased the adsorption capacity of Ni‐MOF‐74 for both CH4 and N2. The packed methyl groups in CH3‐Ni‐MOF‐74 create an environment conducive to CH4, leading to the highest CH4 adsorption capacity. The electrostatic potential distribution indicates that the strong electron‐donating effect introduced by the alkali metal Li results in the highest electrostatic potential gradient in Li‐O‐Ni‐MOF‐74, leading to the strongest adsorption of N2, this is unfavorable for CH4/N2 separation. At 1500 kPa the selectivity order of adsorbents for mixed gases was as follows: CH3‐Ni‐MOF‐74 > NH2‐Ni‐MOF‐74 > OH‐Ni‐MOF‐74 > Ni‐MOF‐74 > Li‐O‐Ni‐MOF‐74. This study highlights that CH3‐Ni‐MOF‐74 possesses optimal CH4 selectivity and adsorption performance. Given the current lack of research on functionalized MOF‐74 for the separation of CH4 and N2, the findings of this study will serve as a theoretical guide and provide references for the applications of CH4 adsorption and CH4/N2 separation. [ABSTRACT FROM AUTHOR]

Nickel‐catalyzed cross‐electrophile coupling reactions of two aliphatic alcohol derivatives remain a challenge. Herein, we report a nickel‐catalyzed reductive methylation reaction of aliphatic mesylates with methyl tosylate. This reaction provides straightforward access to compounds bearing aliphatic methyl groups from alkyl alcohol derivatives. Isotopically labelled substrates and reagents can be employed in the reaction to provide perdeuterated and 13C‐labelled products. This transformation can be achieved by employing stoichiometric Mn reductant or electrochemically. Additionally, mechanistic experiments show that alkyl iodides are key intermediates in the transformation which undergo a stereoablative reaction via radical intermediates. [ABSTRACT FROM AUTHOR]

In nature, hydrogen bonding is a common physical occurrence that has a significant impact on the surroundings of anthocyanins. Water molecules will create hydrogen bonds with anthocyanin molecules in various configurations, but the characteristics of these hydrogen bonds will change. Varied hydrogen bonding characteristics have varied impacts on solvent solutions. This research analyzes the differences in hydrogen bonding qualities caused by different methyl structures, as well as the underlying explanations. In this study, the cyanidin and peonidin structures of anthocyanin molecules were calculated in various stable hydrogen bond configurations using the density functional theory B3LYP/6‐31G(d,p), combined with information from the infrared spectroscopy spectrum, atoms in molecules analysis, interaction energy E, and intermolecular hydrogen bond length. The hydrogen bond structure that is the most stable is determined by analyzing it, as well as the effects of replacing the hydroxyl group with a methyl group and any potential underlying causes. Future anthocyanins research can benefit from the precise theoretical reference that this study can offer. [ABSTRACT FROM AUTHOR]

In this work, the reactions of nonacarbonyldiiron with 8‐alkynyloxyquinoline ligands (L1‐L3) and their resultant iron carbonyl complexes (1a, 1b, 2, and 3) are described. The complexes including the ligands were fully characterized by using a variety of spectroscopic techniques. The four complexes were also crystallographically determined. In the reactions, the quinoline N atom underwent cyclization to form a quinolinium skeleton while the C‐H bond of the quinoline at position 2 or the substituted methyl group was cleaved to form Fe‐C bond(s). Meanwhile, the alkynyl triple bond was reduced to a single bond (1a) or double bonds (1b, 2, and 3) to further coordinate the iron in σ‐bonds or η‐bonds. Particularly, pathways of hydrogenation (1a and 2) and/or dehydrogenation (1b and 3) were accompanied by the reactions. Moreover, the oxidation states of the iron centers in these complexes were identified through analyses of their bond formation, FTIR and NMR spectroscopic signals (1H NMR and DEPT‐135) in combination with their diamagnetic nature, that is, iron (0) for 2 and iron (I) for the rest of the diiron complexes. [ABSTRACT FROM AUTHOR]

Recently, various carbazole‐based self‐assembled monolayers (SAMs) have been investigated for use in the hole transport layer (HTL) of perovskite solar cells (PSCs). In particular, [4‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl)butyl] phosphonic acid (Me‐4PACz) is attracting attention as an HTL for high‐efficiency PSC due to its potential for high open‐circuit voltage (VOC) and fill factor (FF). However, Me‐4PACz has strong hydrophobicity due to its methyl group (–CH3) and long alkyl chain (C4H8), which makes it difficult to deposit a high‐quality perovskite layer on top of conventionally coated Me‐4PACz. In this study, to overcome these limitations, a new SAM deposition method based on a vacuum‐assisted deposition (VD) process is attempted. As a result, a uniform perovskite layer is deposited on top of Me‐4PACz through a very simple VD process, achieving 20.31% efficiency, which is not only close to the highest efficiency among Me‐4PACz‐based PSCs, but also improved long‐term stability of the device. It is believed that the findings of this study can be a cornerstone for using SAM‐based HTL with high hydrophobicity in the future. [ABSTRACT FROM AUTHOR]

Springtails use unique compounds for their outermost epicuticular wax layer, often of terpenoid origin. We report here the structure and synthesis of socialane, the major cuticular constituent of the Collembola Hypogastrura socialis. Socialane is also the first regular nonaprenyl terpene with a cyclic head group. The saturated side chain has seven stereogenic centers, making the determination of the configuration difficult. We describe here the identification of socialane and a synthetic approach using the building blocks farnesol and phytol, enantioselective hydrogenation, and α‐alkylation of sulfones for the synthesis of various stereoisomers. NMR experiments showed the presence of an anti‐configuration of the methyl groups closest to the benzene ring and that the other methyl groups of the polyprenyl side‐chain are not uniformly configured. Furthermore, socialane is structurally different from [6+2]‐terpene viaticene of the closely related H. viatica, showing species specificity of the epicuticular lipids of this genus and hinting at a possible role of surface lipids in the communication of these gregarious arthropods. [ABSTRACT FROM AUTHOR]

Pectin structures have received increasing attention as emergent prebiotics due to their capacity to promote beneficial intestinal bacteria. Yet the collective activity of gut bacterial communities to cooperatively metabolize structural variants of this substrate remains largely unknown. Herein, the characterization of a pectin methylesterase, BpeM, from Bifidobacterium longum subsp. longum, is reported. The purified enzyme was able to remove methyl groups from highly methoxylated apple pectin, and the mathematical modelling of its activity enabled to tightly control the reaction conditions to achieve predefined final degrees of methyl‐esterification in the resultant pectin. Demethylated pectin, generated by BpeM, exhibited differential fermentation patterns by gut microbial communities in in vitro mixed faecal cultures, promoting a stronger increase of bacterial genera associated with beneficial effects including Lactobacillus, Bifidobacterium and Collinsella. Our findings demonstrate that controlled pectin demethylation by the action of a B. longum esterase selectively modifies its prebiotic fermentation pattern, producing substrates that promote targeted bacterial groups more efficiently. This opens new possibilities to exploit biotechnological applications of enzymes from gut commensals to programme prebiotic properties. [ABSTRACT FROM AUTHOR]

In this work, five phenanthroline derivatives substituted with different methyl groups have been selected to synthesize β‐diketonate‐based europium complexes to check the influence of the substitutions on the degradation effect of those complexes in poly(methyl methacrylate) (PMMA) films. The photophysical properties of Eu(III) complexes, including absorbance, excitation, and emission have been carefully investigated in solution, solid‐state, and doped in PMMA film. In all these states, the complexes exhibit an impressive red emission at 614 nm with a high photoluminescence quantum yield of up to 85 %. The films have been exposed under outdoor, indoor, and dark storage stability lifetime conditions for 1200 hours. The photoluminescence measurements recorded every 400, 800, and 1200 hours demonstrated that the film containing europium complex with phenanthroline ligand substituted by a high number of methyl groups (Eu(TTA)3L5) showed good photoluminescent stability in indoor and dark conditions, and exhibited better resistance to degradation in outdoor conditions compared to other complexes. This study has proved that phenanthroline ligands could be tuned chemically leading to better stability of those types of complexes in films which can be end‐used for future stable optoelectronic devices such as luminescent solar concentrators. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) membranes with rich functionality and a tunable pore system are promising for molecular separation. However, an inadequate pore microenvironment and low water stability may hamper the extension of their use in gas separation to liquid separation (e.g., organic solvent dehydration). In this study, we report a high‐valence Zr‐MOF membrane with high stability and tunable pore microenvironment, prepared using a mixed‐ligand strategy based on fumarate (fum) and 2‐methylfumarate (mes) ligands for the pervaporation dehydration of alcohols. The introduction of a methyl group in the ligand side chain narrowed the aperture size while balancing the hydrophilicity, thus facilitating the fast and selective permeation of water over alcohol molecules. The resulting mes/fum‐Zr‐MOF membrane with a mes content of 30% displayed excellent butanol/water separation performance with total flux of 5226 g−1·m−2·h−1, separation factor of 1281, and water content of 99.3% in the permeate, transcending the upper‐bound of state‐of‐the‐art MOF and polymer membranes, thereby exhibiting immense potential for alcohols dehydration. [ABSTRACT FROM AUTHOR]

2,4‐dimethylfuran has a rare disubstitution pattern in the five‐membered heterocyclic furan ring that is highly interesting chemically but challenging to access synthetically. We present a heterogeneously catalysed route to synthesise 2,4‐dimethylfuran from commonly available 2,5‐dimethylfuran using a zeolite packed‐bed flow reactor. As supported by DFT calculations, the reaction occurs inside the zeolite channels, where the acid sites catalyse proton transfer followed by migration of a methyl group. The zeotype Ga‐silicate (MFI type) appears superior to an aluminium‐containing ZSM‐5 by demonstrating higher selectivities and slower catalyst deactivation. This work provides new opportunities for the continuous valorisation of bio‐feedstock molecules in the perspective of the emerging biorefinery era. [ABSTRACT FROM AUTHOR]

In this paper, three epoxy resin systems commonly used in power equipment are prepared to obtain cross‐linked networks with structural differences. The relationship between microscopic structures and dielectric properties of epoxy resins is investigated and discussed. Experimental results show that the polarization and conductance losses are inhibited in the anhydride‐cured systems with methyl groups. The molecular dynamics (MD) simulation shows that rigid anhydride structures (such as methyl groups) play a major role in reducing the local segment mobility and increasing the free volume at cross‐linking points. The decrease in local segment mobility has been confirmed by the decrease of mean square displacement (MSD) at the cross‐linking points, which is consistent with the change of measured polarization and conductance loss. In the glassy state, the dielectric properties of different anhydride‐cured systems can be reflected by local MSD at the cross‐linking points. At high temperatures near the glass transition temperature, both the free volume and network mobility increase significantly, which reflects the increased dielectric relaxation strength and conductance loss. The understanding of the structure–property relationships could provide a theoretical foundation for epoxy modification in a controlled manner for power equipment applications. [ABSTRACT FROM AUTHOR]

Three novel mononuclear 4‐vinylpyridine‐based Fe(III) complexes [FeL(4‐VP)]BPh4 (4‐VP=4‐vinylpyridine; H2L=bis(salicylicdeneaminopropyl)amine, H2salten, 1; H2L=bis(salicylicdeneaminopropyl)methylamine, H2saltenMe, 2; H2L=bis(3‐methoxysalicylideneaminopropyl)methylamine, 3‐OMeH2saltenMe, 3) were synthesized and characterized. Single‐crystal X‐ray diffraction analyses revealed that 1–3 both present the mononuclear structure based on 4‐VP coordinated with bis(salicylicdeneaminopropyl)amine and its derivatives, which give 2D architectures by various interactions among cations and counter‐ions. Magnetic studies showed that both 1 and 2 exhibit one‐step complete spin‐crossover (SCO) behaviours with critical transition temperatures (T1/2) of 178 and 87 K respectively, while 3 exhibits one‐step incomplete spin crossover behaviour (T1/2,3=93 K). The introduction of methyl groups on the amine nitrogen of the Schiff base ligands in 2 and 3 give the bigger repulsive effect, further decrease the cooperation of spin centres, resulting in their spin transition occurring at lower temperatures. In addition, the presence of C−H⋯O weak interactions in 1 and 3 with synergistic effect, led to their spin transition temperatures being higher than that of 2. [ABSTRACT FROM AUTHOR]

Lignin represents the largest aromatic carbon resource in plants, holding significant promise as a renewable feedstock for bioaromatics and other cyclic hydrocarbons in the context of the circular bioeconomy. However, the methoxy groups of aryl methyl ethers, abundantly found in technical lignins and lignin‐derived chemicals, limit their pertinent chemical reactivity and broader applicability. Unlocking the phenolic hydroxyl functionality through O‐demethylation (ODM) has emerged as a valuable approach to mitigate this need and enables further applications. In this review, we provide a comprehensive summary of the progress in the valorization of technical lignin and lignin‐derived chemicals via ODM, both catalytic and non‐catalytic reactions. Furthermore, a detailed analysis of the properties and potential applications of the O‐demethylated products is presented, accompanied by a systematic overview of available ODM reactions. This review primarily focuses on enhancing the phenolic hydroxyl content in lignin‐derived species through ODM, showcasing its potential in the catalytic funneling of lignin and value‐added applications. A comprehensive synopsis and future outlook are included in the concluding section of this review. [ABSTRACT FROM AUTHOR]

The coordination nature of 2‐mono‐ and 2,6‐disubstituted pyridines with electron‐withdrawing halogen and electron‐donating methyl groups for [N−X−N]+ (X=I, Br) complexations have been studied using 15N NMR, X‐ray crystallography, and Density Functional Theory (DFT) calculations. The 15N NMR chemical shifts reveal iodine(I) and bromine(I) prefer to form complexes with 2‐substituted pyridines and only 2,6‐dimethylpyridine. The crystalline halogen(I) complexes of 2‐substituted pyridines were characterized by using X‐ray diffraction analysis, but 2,6‐dihalopyridines were unable to form stable crystalline halogen(I) complexes due to the lower nucleophilicity of the pyridinic nitrogen. In contrast, the halogen(I) complexes of 2,6‐dimethylpyridine, which has a more basic nitrogen, are characterized by X‐crystallography, which complements the 15N NMR studies. DFT calculations reveal that the bond energies for iodine(I) complexes vary between −291 and −351 kJ mol−1 and for bromine between −370 and −427 kJ mol−1. The bond energies of halogen(I) complexes of 2‐halopyridines with more nucleophilic nitrogen are 66‐76 kJ mol−1 larger than those of analogous 2,6‐dihalopyridines with less nucleophilic nitrogen. The experimental and DFT results show that the electronic influence of ortho‐halogen substituents on pyridinic nitrogen leads to a completely different preference for the coordination bonding of halogen(I) ions, providing new insights into bonding in halogen(I) chemistry. [ABSTRACT FROM AUTHOR]

5‐Azacytosine (5‐AC) is one of the best interesting noncanonical nucleobases due to its functionalization and structural imitation of natural bases. 5‐AC can be used as the scaffold of two important chemotherapeutic medicines, 5‐azacytidine and 2′‐deoxy‐5‐azacytidine. Furthermore, increased sensitivity to UV leads to the photochemical effects of 5‐AC also attracted attention. Yet, no study has been reported to explore the effect of glycosyl groups on the photophysical and photochemical properties of 5‐AC, which can help to reveal the photostability of related actual clinic drugs. In this study, the excited‐state dynamics of 5‐azacytidine and 2′‐deoxy‐5‐azacytidine are studied by femtosecond transient absorption and quantum‐chemical calculations while revisiting that of 5‐AC with a wider probe spectral range. It is shown that glycosyl substitution on the N1 position leads to ultrafast excited‐state relaxation within several picoseconds in both nucleosides, which is distinct compared with the 17 ps lifetime seen in 5‐AC. It is proposed that these changes are due to altering the energy level of the dark nπ* state. Moreover, our results suggest that it should be cautioned to simply replace sugar groups with methyl groups when doing a theoretical calculation study on nucleobases and their derivatives. [ABSTRACT FROM AUTHOR]

5‐Azacytosine (5‐AC) is one of the best interesting noncanonical nucleobases due to its functionalization and structural imitation of natural bases. 5‐AC can be used as the scaffold of two important chemotherapeutic medicines, 5‐azacytidine and 2′‐deoxy‐5‐azacytidine. Furthermore, increased sensitivity to UV leads to the photochemical effects of 5‐AC also attracted attention. Yet, no study has been reported to explore the effect of glycosyl groups on the photophysical and photochemical properties of 5‐AC, which can help to reveal the photostability of related actual clinic drugs. In this study, the excited‐state dynamics of 5‐azacytidine and 2′‐deoxy‐5‐azacytidine are studied by femtosecond transient absorption and quantum‐chemical calculations while revisiting that of 5‐AC with a wider probe spectral range. It is shown that glycosyl substitution on the N1 position leads to ultrafast excited‐state relaxation within several picoseconds in both nucleosides, which is distinct compared with the 17 ps lifetime seen in 5‐AC. It is proposed that these changes are due to altering the energy level of the dark nπ* state. Moreover, our results suggest that it should be cautioned to simply replace sugar groups with methyl groups when doing a theoretical calculation study on nucleobases and their derivatives. [ABSTRACT FROM AUTHOR]

The ortho C−H methylation and ipso C−O alkenylation of aryl triflates was regio‐selectively achieved in one pot by palladium/norbornene (NBE) synergistic catalysis. This work provides an efficient method for preparing poly‐substituted aromatics with (deuterated) methyl and alkenyl groups from the readily available phenoxides. [ABSTRACT FROM AUTHOR]

Developing efficient catalytic processes for obtaining biobased monomers for plastics can significantly contribute to a more sustainable economy. The biomass‐derived and chemical platform 5‐hydroxymethylfurfural (HMF) can be converted to various key intermediates, which is often hampered by side reactions due to the reactive nature of the formyl group in HMF. Here, we present a stepwise approach involving a protecting agent to obtain dimethyl furan‐2,5‐dicarboxylate (MFDC), which is a monomer for polyalkylene furanoates, a new class of biobased polyesters. Methanol is used as a solvent, reactant, and protecting agent for HMF's formyl group. In the first step, the oxidative esterification of the hydroxymethyl group to methyl carboxylate in HMF‐dimethylacetal catalyzed by Au/CeO2 affords methyl 5‐formylfuran‐2‐carboxylate dimethylacetal (MFFC‐acetal) in high yields (>90 %) from concentrated methanolic solutions (~20 wt %). Without protecting agent, a mixture of methyl‐5‐hydroxymethylfuran‐2‐carboxylate (MHMFC), MFDC, and humin byproduct was obtained. The deprotection of MFFC‐acetal in the second step proceeded efficiently in acetone with Amberlyst‐15, affording MFFC in a >90 % yield. In the final step, oxidative esterification of MFFC in methanol (10 wt %) afforded MFDC in a 93 % yield using Au/CeO2. The acetal protection strategy with methanol offers an efficient route toward MFDC in two oxidative esterification steps. [ABSTRACT FROM AUTHOR]

Converting CO2 to olefins is an ideal route to achieve carbon neutrality. However, selective hydrogenation to light olefins, especially single‐component olefin, while reducing CH4 formation remains a great challenge. Herein, we developed ZnZrOx/SSZ‐13 tandem catalyst for the highly selective hydrogenation of CO2 to light olefins. This catalyst shows C2=−C4= and propylene selectivity up to 89.4 % and 52 %, respectively, while CH4 is suppressed down to 2 %, and there is no obvious deactivation. It is demonstrated that the isolated moderate Brønsted acid sites (BAS) of SSZ‐13 promotes the rapid conversion of intermediate species derived from ZnZrOx, thereby enhancing the kinetic coupling of the reactions and inhibit the formation of alkanes and improve the light olefins selectivity. Besides, the weaker BAS of SSZ‐13 promote the conversion of intermediates into aromatics with 4–6 methyl groups, which is conducive to the aromatics cycle. Accordingly, more propene can be obtained by elevating the Si/Al ratio of SSZ‐13. This provides an efficient strategy for CO2 hydrogenation to light olefins with high selectivity. [ABSTRACT FROM AUTHOR]

We describe a family of cationic methylstannylene and chloro‐ and azidosilylene organoplatinum(II) complexes supported by a neutral, binucleating ligand. Methylstannylenes MeSn:+ are stabilized by coordination to PtII and are formed by facile Me group transfer from dimethyl or monomethyl PtII complexes, in the latter case triggered by concomitant B−H, Si−H, and H2 bond activation that involves hydride transfer from Sn to Pt. A cationic chlorosilylene complex was obtained by formal HCl elimination and Cl− removal from HSiCl3 under ambient conditions. The computational studies show that stabilization of cationic methylstannylenes and cationic silylenes is achieved through weak coordination to a neutral N‐donor ligand binding pocket. The analysis of the electronic potentials, as well as the Laplacian of electron density, also reveals the differences in the character of Pt−Si vs. Pt−Sn bonding. We demonstrate the importance of a ligand‐supported binuclear Pt/tetrel core and weak coordination to facilitate access to tetrylium‐ylidene Pt complexes, and a transmetalation approach to the synthesis of MeSnII:+ derivatives. [ABSTRACT FROM AUTHOR]

Histone modifications play a critical role in the control over activities of the eukaryotic genome; among these chemical alterations, the methylation of lysine K9 in histone H3 (H3K9) is one of the most extensively studied. The number of enzymes capable of methylating H3K9 varies greatly across different organisms: in fission yeast, only one such methyltransferase is present, whereas in mammals, 10 are known. If there are several such enzymes, each of them must have some specific function, and they can interact with one another. Thus arises a complex system of interchangeability, "division of labor," and contacts with each other and with diverse proteins. Histone methyltransferases specialize in the number of methyl groups that they attach and have different intracellular localizations as well as different distributions on chromosomes. Each also shows distinct binding to different types of sequences and has a specific set of nonhistone substrates. [ABSTRACT FROM AUTHOR]

S‐Adenosyl‐l‐methionine (SAM)‐dependent methyltransferases (MTs) are highly chemoselective enzymes grouped in C‐, N‐, O‐, S‐ and halide MTs, depending on the (hetero) atom that acts as the methyl group acceptor. So far, OMTs present the largest group, including many well investigated candidates. The catechol OMT from mammals such as from Rattus norvegicus (RnCOMT) is involved in the metabolism of neurotransmitters like dopamine. It is known to methylate the hydroxyl of the catechol ring in the 3 position. There are also reports showing that the regioselectivity of different COMTs can vary leading to different products with methyl groups in the 3 and or 4 positions. Nevertheless, there was only O‐methylation reported for COMTs. Another related MT, the caffeate OMT involved in the lignin biosynthesis of plants has also been reported as a chemoselective enzyme. In nature, S‐methylation is a rare phenomenon with different methyl donors being involved in the methyl transfer onto sulfur atoms. Several SAM‐dependent MTs are identified as S‐methyltransferases (SMTs), these are involved in salvaging pathways and xenobiotic metabolism of cells. Here, we report a new function of three OMTs; RnCOMT, a COMT from Myxococcus xanthus (MxSafC), and a CaOMT from Prunus persica (PpCaOMT) with acceptance towards different aromatic thiol substrates with up to full conversion. [ABSTRACT FROM AUTHOR]

We introduce a strategy for the one‐step synthesis of chiral diazabicycloalkanes that delivers the annulated ring system in a single reaction step. The method entails a direct aza‐Michael/aldol reaction of enals in conjunction with modified oxopropanamides and establishes the chiral center via iminium‐enamine tandem catalysis. For this purpose, we developed simple diphenylethylendiamine frameworks as dual activation organocatalyst, effectively engaging both the substrate and reagent, thus leading to yields of 31–86% and enantioselectivities in the range of 80–98%. The final product features not only the diazabicycloalkane moiety but includes also additional functionalities, such as aldehyde motives that can be modified in situ without loss of enantioselectivity, and an sp2‐bearing methyl group. Our approach accommodates a wide array of enals with high functional group tolerance. Additionally, we demonstrated the adjustability of enantioselectivity and yield by modulating the acid cocatalyst's quantity, thus offering multiple optimization possibilities. [ABSTRACT FROM AUTHOR]

Direct C−H methylation is a highly valuable approach for introducing methyl groups into organic molecules, particularly in pharmaceutical chemistry. Among the various methodologies available, photo‐induced methylation stands out as an exceptional choice due to its mild reaction conditions, energy efficiency, and compatibility with functional groups. This article offers a comprehensive review of photochemical strategies employed for the direct and selective methylation of C(sp3)−H, C(sp2)−H, and C(sp)−H bonds in various organic molecules. The discussed methodologies encompass transition‐metal‐based photocatalysis, organophotocatalysis, as well as other metal‐free approaches, including electron donor‐acceptor (EDA)‐enabled transformations. Importantly, a wide range of easily accessible agents such as tert‐butyl peroxide, methanol, DMSO, methyl tert‐butyl ether, TsOMe, N‐(acetoxy)phthalimide, acetic acid, methyl halides, and even methane can serve as effective methylating reagents for modifying diverse targets. These advancements in photochemical C−H methylation are anticipated to drive further progress in the fields of organic synthesis, photocatalysis, and pharmaceutical development, opening up exciting avenues for creating novel organic molecules and discovering new drug compounds. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have witnessed great success in green, red, and near‐infrared light‐emitting diodes (LEDs), yet blue LEDs still lag behind. Reducing undesired energetic disorders – broad n‐phases and halide segregation – is considered as the most critical strategy to further improve the performances. Here, the study reports a newly designed and synthesized di‐ammonium ligand with rigid π‐conjugated rings and additional methyl groups to construct Dion–Jacobson (DJ) structure. Augmented coordination from the extra ammonium site and increased effective bulkiness from methyl groups lead to better distribution control over conventional mono‐ammonium ligands. This enhances the radiative recombination of blue emissions in the film with homogeneous energy landscape and improved surface morphology, as evidenced by a series of imaging and mapping techniques. As a result, it demonstrates DJ perovskite LEDs (PeLEDs) with peak external quantum efficiencies of ≈4% at 484 nm and ≈11% at 494 nm, which are among the top reported for pure DJ phase‐based PeLEDs in the corresponding wavelength regions. The results deepen the understanding of regulating energetic disorders in perovskite materials via molecular engineering. [ABSTRACT FROM AUTHOR]

Here we report the use of a base metal complex [(tBupyrpyrr2)Fe(OEt2)] (1‐OEt2) (tBupyrpyrr22−=3,5‐tBu2‐bis(pyrrolyl)pyridine) as a catalyst for intermolecular amination of Csp3−H bonds of 9,10‐dihydroanthracene (2 a) using 2,4,6‐trimethyl phenyl azide (3 a) as the nitrene source. The reaction is complete within one hour at 80 °C using as low as 2 mol % 1‐OEt2 with control in selectivity for single C−H amination versus double C−H amination. Catalytic C−H amination reactions can be extended to other substrates such as cyclohexadiene and xanthene derivatives and can tolerate a variety of aryl azides having methyl groups in both ortho positions. Under stoichiometric conditions the imido radical species [(tBupyrpyrr2)Fe{=N(2,6‐Me2‐4‐tBu‐C6H2)] (1‐imido) can be isolated in 56 % yield, and spectroscopic, magnetometric, and computational studies confirmed it to be an S = 1 FeIV complex. Complex 1‐imido reacts with 2 a to produce the ferrous aniline adduct [(tBupyrpyrr2)Fe{NH(2,6‐Me2‐4‐tBu‐C6H2)(C14H11)}] (1‐aniline) in 45 % yield. Lastly, it was found that complexes 1‐imido and 1‐aniline are both competent intermediates in catalytic intermolecular C−H amination. [ABSTRACT FROM AUTHOR]

Novel 1‐(ethyl/methyl)‐7‐(p‐methoxybenzyl amino) and 7‐amino‐6‐fluoroquinolone‐boron difluoride complexes were synthesized, and their biological activity was studied, comparing the influence of the nature of 7‐substituent as well as N‐1 substituent. The quinolone compounds were characterized by IR, UV‐Vis, 1H, 13C{1H} and 19F{1H} NMR, and mass spectrometry. The antiproliferative effect of the new fluoroquinolone‐boron complexes in breast cancer (BC) derived cell lines MCF‐7 and SKBR‐3 was investigated. Compounds 9 b and 9 a showed antiproliferative in MCF‐7 cells, and 9 b, 11 b, 9 a, 7 a, 7b and 8 a showed similar effects in SKBR‐3 cells. Derivatives with p‐methoxybenzyl amino moieties at C‐7 and an ethyl or methyl group at N‐1 in the fluoroquinolone ring (9 a and 9 b) were the more efficient in both breast cancer cell lines. In addition, an 8‐nitro group to the fluoroquinolone (11 b) improved activity against SKBR‐3 cell proliferation. These compounds represent potential drug candidates for breast cancer treatment. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations were performed to study structural and dynamic properties of polar butanamine/water/butanamine, pentanoic acid/water/pentanoic acid, butanethiol/water/butanethiol, and nonpolar pentane/water/pentane systems. The mass density profiles along the interface normal to the organic liquid/water system, the difference in the local structure of H2O molecules in bulk and in the vicinity of interface, as well as the diffusion behavior of water molecules at the interface with above‐mentioned organic liquids have been investigated. Our MD simulation has shown that the diffusion of water molecules across the water/organic liquid interface is influenced by the hydrogen bonds nHB between water molecules and the terminal groups of organic liquids. It was found that the loss of the hydrogen bonds nHB in the nonpolar organic liquid leads to a decrease in the value of the normal component of the diffusion coefficient Dz, while the tangential diffusion coefficients, both Dx and Dy, increase. [ABSTRACT FROM AUTHOR]

Carboxy to methyl reduction is an important transformation in organic synthesis, yet existing methodologies often require multi‐step procedures or use hazardous metal hydrides. Herein, a metal‐free catalytic system is reported for the one‐step reduction of esters, carboxylic acids, and carbamates to a methyl group, in the presence of catalytic amounts of boronic acids. By using ammonia borane as a hydrogen donor, a wide range of products bearing different functional groups can be obtained in high yields under relatively mild conditions. Mechanistic studies and control experiments elucidate the complexity of the mechanism and provide an explanation for the observed selectivity. [ABSTRACT FROM AUTHOR]

Six new diiridium complexes containing 2‐methyl‐6‐phenylpyridyl as the cyclometalating ligand with a μ2‐oxamidato or a μ2‐dithioxamidato ligand as the bridge have been synthesized in 60–73 % yields. These complexes were revealed by multinuclear NMR spectroscopy to contain inseparable mixtures of diastereomers (rac, ΔΔ/ΛΛ and meso, ΔΛ) with bridges in anti and syn configurations. The remarkable variety of isomers present was confirmed by X‐ray crystallography on single crystals grown from mixtures of each complex. In one complex with a N,N'‐bis(4‐trifluoromethylphenyl)‐μ2‐oxamidato bridge, two single crystals of anti and syn isomers were structurally determined. Two single crystals of the μ2‐dithioxamidato bridge complex were found to contain rac and meso forms of the syn isomer. Hybrid DFT computations on the four isomers of each diiridium complex revealed negligible energetic preferences for one isomer despite the methyl groups in the 2‐methyl‐6‐phenylpyridyl cyclometalating ligands being close to the neighboring methyl groups and the bridge, thus supporting the experimental findings of isomer mixtures. Two distinct broad emissions with maxima at 522–529 nm and at 689–701 nm observed in these complexes in dichloromethane are attributed to mixed metal‐ligand to ligand charge transfer (MLLCT) excited states involving the pyridyl and bridge moieties respectively with the aid of electronic structure computations. [ABSTRACT FROM AUTHOR]

BACKGROUND: Previously, the herbicidal activity of N‐benzyl‐2‐methoxybenzamides was discovered during a random screening program in our laboratory. The chemicals resulted in bleaching effect of newly grown leaves by interfering with the biosynthesis of β‐carotene in plant. RESULTS: A total of 28 benzamides were synthesized and subjected for the evaluation of herbicidal activity. Structure–activity relationship (SAR) showed that introducing propargyloxy group at 5‐position of benzoyl‐benzene ring and fluorine or methyl group at 3‐ or 4‐position of benzyl‐benzene ring is beneficial for the activity. Post‐emergence herbicidal activities of compounds 406 and 412 were comparable to those of mesotrione and diflufenican. Studies on MOA showed that 406 decreased the level of both β‐carotene and plastoquinone (PQ) in treated plants. The bleaching effect in green alga caused by 406 could be reversed by supplying exogenous homogentisic acid (HGA), the precursor of plastoquinone. CONCLUSION: N‐benzyl‐2‐methoxy‐5‐propargyloxybenzoamides were discovered as new candidates for bleaching herbicides. Preliminary investigation on mechanism of action (MOA) showed that the title compounds might indirectly interfere with carotenoid biosynthesis by blocking the production of PQ. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Methylation reactions are of significant interest when generating pharmaceutically active molecules and building blocks for other applications. Synthetic methylating reagents are often toxic and unselective due to their high reactivity. S‐Adenosyl‐l‐methionine (SAM)‐dependent methyltransferases (MTs) present a chemoselective and environmentally friendly alternative. The anthranilate N‐MT from Ruta graveolens (RgANMT) is involved in acridone alkaloid biosynthesis, methylating anthranilate. Although it is known to methylate substrates only at the N‐position, the closest relatives with respect to amino acid sequence similarities of over 60 % are O‐MTs catalysing the methylation reaction of caffeate and derivatives containing only hydroxyl groups (CaOMTs). In this study, we investigated the substrate range of RgANMT and a CaOMT from Prunus persica (PpCaOMT) using compounds with both, an amino‐ and hydroxyl group (aminophenols) as possible methyl group acceptors. For both enzymes, the reaction was highly chemoselective. Furthermore, generating cofactor derivatives in situ enabled the transfer of other alkyl chains onto the aminophenols, leading to an enlarged pool of products. Selected MT reactions were performed at a preparative biocatalytic scale in in vitro and in vivo experiments resulting in yields of up to 62 %. [ABSTRACT FROM AUTHOR]

Alkylation of one of the inner‐core nitrogen atoms is one possible approach to obtain dianionic corrole ligands, suitable for the coordination of divalent metal ions, such as PdII. Inner‐core N‐methylation can be obtained by treating the corrole with CH3I, but the reaction conditions should be optimized to limit the formation of the dimethylated derivative. Two regioisomers, the N‐21 and the N‐22 methyl derivatives are obtained from the reaction, with the first product achieved in a higher amount. Structural characterization of the reaction products evidenced the distortion induced by the introduction of the methyl groups; the N‐methylcorroles are chiral compounds, and the enantiomers were separated by chromatography, with their absolute configuration assigned by ECD computation. Palladium insertion was achieved in the case of monosubstituted corroles, but not with the dimethylated macrocycle; X‐ray characterization of the complexes showed the distortion of the macrocycles. The Pd complexes do not show luminescence emission, but are able to produce singlet oxygen upon irradiation. The PdII complexes were also inserted in human serum albumin (HSA) and dispersed in water; in this case, the protein protects the corroles from photobleaching, and a switch from the type II to the type I mechanism in reactive oxygen species (ROS) production is observed. [ABSTRACT FROM AUTHOR]

Insolubility of functional molecules caused by polymorphism sometimes poses limitations for their solution‐based processing. Such a situation can also occur in the preparation processes of supramolecular polymers formed in a solution. An effective strategy to address this issue is to prepare amorphous solid states by introducing a "coformer" molecule capable of inhibiting the formation of an insoluble polymorph through co‐aggregation. Herein, inspired by the coformer approach, we demonstrated a solubility enhancement of a barbiturate π‐conjugated compound that can supramolecularly polymerize through six‐membered hydrogen‐bonded rosettes. Our newly synthesized supramolecular coformer molecule features a sterically demanding methyl group in the π‐conjugated unit of the parent molecule. Although the parent molecule exhibits low solubility in nonpolar solvents due to the formation of a crystalline polymorph comprising a tape‐like hydrogen‐bonded array prior to the supramolecular polymerization, mixing with the coformer compound enhanced the solubility by inhibiting mesoscopic organization of the tapes. The two monomers were then co‐polymerized into desired helicoidal supramolecular polymers through the formation of heteromeric rosettes. [ABSTRACT FROM AUTHOR]

In the development of an efficient 18F‐labeling method for the synthesis of PET tracers, it is essential not only to improve the efficiency of [18F]fluorine incorporation into a carrier but also to minimize non‐radioactive side products from the precursor. Highly reactive sulfonate esters are promising precursors for 18F‐nucleophilic fluorination under mild conditions. However, the expected labeling efficiency from the precursor is often hampered by its competitive degradation due to coexisting bases during 18F‐fluorination. In this report, we designed a 2‐methyl‐6‐nitrobenzenesulfonate (2‐MeNs) ester as a precursor for 18F‐fluorination, in which the methyl group suppresses hydrolysis of the sulfonate ester via steric hindrance. An increase in labeling efficiency in the 18F‐labeling of a neopentyl labeling group was observed for the neopentyl 2‐MeNs ester compared with that of the 2‐nitrobenzenesulfonate ester. Ultimately, we achieved the automated synthesis of an 18F‐labeled amino acid using a neopentyl labeling group by using a 2‐MeNs ester as a precursor. [ABSTRACT FROM AUTHOR]

Herein, a 2‐fold interpenetrated metal‐organic framework (MOF) Zn‐BPZ‐TATB with accessible N/O active sites in nonpolar pore surfaces was reported for one‐step C2H4 purification from C2H6 or C3H6 mixtures as well as recovery of C3H6 from C2H6/C3H6/C2H4 mixtures. The MOF exhibits the favorable C2H6 and C3H6 uptakes (>100 cm3 g−1 at 298 K under 100 kPa) as well as selective adsorption of C2H6 and C3H6 over C2H4. The C3H6‐ and C2H6‐selective feature were investigated detailedly by experimental tests as well as sorption kinetic studyies. Molecular modelling revealed the multiple interactions between C3H6 or C2H6 molecules and methyl groups as well as triazine rings in pores. Zn‐BPZ‐TATB not only can directly generate 323.4 L kg−1 and 15.4 L kg−1 of high‐purity (≥99.9 %) C2H4 from C3H6/C2H4 and C2H6/C2H4 mixtures, but also provide a large high‐purity (≥99.5 %) C3H6 recovery capacity of 60.1 L kg−1 from C3H6/C2H4 mixtures. More importantly, the high‐purity C3H6 (≥99.5 %) and C2H4 (≥99.9 %) with the productivities of 38.2 and 12.7 L kg−1 can be simultaneously obtained from C2H6/C3H6/C2H4 mixtures through a single adsorption/desorption cycle. [ABSTRACT FROM AUTHOR]

Herein, a 2‐fold interpenetrated metal‐organic framework (MOF) Zn‐BPZ‐TATB with accessible N/O active sites in nonpolar pore surfaces was reported for one‐step C2H4 purification from C2H6 or C3H6 mixtures as well as recovery of C3H6 from C2H6/C3H6/C2H4 mixtures. The MOF exhibits the favorable C2H6 and C3H6 uptakes (>100 cm3 g−1 at 298 K under 100 kPa) as well as selective adsorption of C2H6 and C3H6 over C2H4. The C3H6‐ and C2H6‐selective feature were investigated detailedly by experimental tests as well as sorption kinetic studyies. Molecular modelling revealed the multiple interactions between C3H6 or C2H6 molecules and methyl groups as well as triazine rings in pores. Zn‐BPZ‐TATB not only can directly generate 323.4 L kg−1 and 15.4 L kg−1 of high‐purity (≥99.9 %) C2H4 from C3H6/C2H4 and C2H6/C2H4 mixtures, but also provide a large high‐purity (≥99.5 %) C3H6 recovery capacity of 60.1 L kg−1 from C3H6/C2H4 mixtures. More importantly, the high‐purity C3H6 (≥99.5 %) and C2H4 (≥99.9 %) with the productivities of 38.2 and 12.7 L kg−1 can be simultaneously obtained from C2H6/C3H6/C2H4 mixtures through a single adsorption/desorption cycle. [ABSTRACT FROM AUTHOR]