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The development of optoelectronically‐active soft materials is drawing attention to the application of soft electronics. A room‐temperature solvent‐free liquid obtained by modifying a π‐conjugated moiety with flexible yet bulky alkyl chains is a promising functional soft material. Tuning the elastic modulus (G′) is essential for employing optoelectronically‐active alkyl–π liquids in deformable devices. However, the range of G′ achieved through the molecular design of alkyl–π liquids is limited. We report herein a method for controlling G′ of alkyl–π liquids by gelation. Adding 1 wt % low‐molecular‐weight gelator formed the alkyl–π functional molecular gel (FMG) and increased G′ of alkyl–π liquids by up to seven orders of magnitude while retaining the optical properties. Because alkyl–π FMGs have functional π‐moieties in the gel medium, this new class of gels has a much higher content of π‐moieties of up to 59 wt % compared to conventional π‐gels of only a few wt %. More importantly, the gel state has a 23 % higher charge‐retention capacity than the liquid, providing better performance in deformable mechanoelectric generator‐electret devices. The strategy used in this study is a novel approach for developing next‐generation optoelectronically‐active FMG materials. [ABSTRACT FROM AUTHOR]

Supramolecular gels are generally formed by the self-assembly of organic molecules called low-molecular-weight gelators. However, supramolecular gels can also be formed with the assistance of metal ions. These organic-inorganic hybrids are key for creating highly functional materials. Unique properties and functions that cannot be obtained from organic molecules alone are observed in the metal ion containing supramolecular gels. In this study, several examples of supramolecular gels formed with the assistance of metal ions, cholesterol derivatives, amino acids and peptides, nucleic acid derivatives, oxalic acid, and C3-symmetric tris-urea derivatives are introduced. This provides an overview of existing supramolecular gels to better understand the scope for possible future research for their practical applications. [ABSTRACT FROM AUTHOR]

Benzo[de]chromene‐7,8‐dione derivatives are known to have important biological and pharmacological properties. Thus, a novel and efficient method was developed for the synthesis of benzo[de]chromene‐7,8‐dione derivatives via the tandem reaction of 5‐bromo‐2‐hydroxynaphthalene‐1,4‐dione and terminal alkynes, which proceeds under the typical reaction conditions for Sonogashira coupling using Pd and Cu catalysts. The process likely occurs via a tandem reaction due to the synthesized Sonogashira coupling product undergoing intramolecular cyclization in the presence of a Cu catalyst. This method is superior to existing synthesis methods in that it can access benzo[de]chromene‐7,8‐dione compounds without the post‐oxidation of benzo[de]chromenes. Furthermore, it enables the direct supply of several biologically active compounds. The minimum inhibitory concentrations (MICs) of the synthesized compounds against multidrug efflux pump‐deficient strains of S. aureus, E. coli, and P. aeruginosa and their parent strains were determined. Certain synthesized compounds exhibited strong antimicrobial activity, indicating that they are substrates for multidrug efflux pumps. [ABSTRACT FROM AUTHOR]

The self-assembling of tetrakis(4-hydroxyphenyl)-cavitand and terta(4-pyridyl) cavitand into a heterodimeric capsule by the four ArOH...pyridyl hydrogen bonds in CD[Cl.sub.3] with high thermodynamic stability is described. The balance among electrostatic potential repulsion, CH-[pi] interaction, in tetrakis(4-hydroxyphenyl)-cavitand and terta(4-pyridyl) cavitand-guest assembly has affected the orientational isomeric selectivity of unsymmetrical guests within tetrakis(4-hydroxyphenyl)-cavitand and terta(4-pyridyl) cavitand.

Fine and/or drastic tuning of the capsule space was achieved by alteration of the hydrogen-bonding linker and/or hemispherical cavitand, respectively. This simple operation based on the combination of cavitands and hydrogen-bonding linkers provides highly tunable capsule space, which brings about a dramatic change of the guest-encapsulation selectivity.

A study is conducted to present the formation of a homo or hetero cavitand cage comprising of two kinds of ligands with different coordination ability as donors on metal and as an acceptor like tetra (4-pytidyl)-cavitand and Pt (dppp)(OTF)(sub 2). The results prove that the selectivity for the self-assembly of the homo or hetero cavitand cage is controlled by the balance between kinetic and thermodynamic stabilities of cages depending on factors like coordination ability and steric demand of the cavitands.

Research has been conducted on the pyridine derivatives from alkynes and nitrile. Results indicate that these derivatives have been formed via azazirconacyclopentadiene reaction with propargyl halides in the presence of CuCl.

Alzheimer's disease (AD) causes cognitive impairment in the elderly and is a severe problem worldwide. One of the major reasons for the pathogenesis of AD is thought to be due to the accumulation of amyloid beta (Aβ) peptides that result in neuronal cell death in the brain. In this study, bioassay‐guided fractionation was performed to develop seed compounds for anti‐AD drugs that can act as dual inhibitors of BACE1 and Aβ aggregation from secondary metabolites produced by Streptomyces sp. To improve the solubility, the crude extracts were methylated with trimethylsilyl (TMS) diazomethane and then purified to yield polyketides 1–5, including the new compound 1. We synthesized the compounds 6 and 7 (original compounds 2 and 3, respectively), and their activities were evaluated. KS‐619‐1, the demethylated form of 4 and 5, was isolated and evaluated for its inhibitory activity. The IC50 values for BACE1 and Aβ aggregation were found to be 0.48 and 1.1 μM, respectively, indicating that KS‐619‐1 could be a lead compound for the development of therapeutic agents for AD. [ABSTRACT FROM AUTHOR]

Maltose is a ubiquitous disaccharide produced by the hydrolysis of starch. Amphiphilic ureas bearing hydrophilic maltose moiety were synthesized via the following three steps: I) construction of urea derivatives by the condensation of 4‐nitrophenyl isocyanate and alkylamines, II) reduction of the nitro group by hydrogenation, and III) an aminoglycosylation reaction of the amino group and the unprotected maltose. These amphiphilic ureas functioned as low molecular weight hydrogelators, and the mixtures of the amphipathic ureas and water formed supramolecular hydrogels. The gelation ability largely depended on the chain length of the alkyl group of the amphiphilic urea; amphipathic urea having a decyl group had the highest gelation ability (minimum gelation concentration=0.4 mM). The physical properties of the supramolecular hydrogels were evaluated by measuring their thermal stability and dynamic viscoelasticity. These supramolecular hydrogels underwent gel‐to‐sol phase transition upon the addition of α‐glucosidase as a result of the α‐glucosidase‐catalyzed hydrolysis of the maltose moiety of the amphipathic urea. [ABSTRACT FROM AUTHOR]

Urea derivatives that were substituted with a 2‐benzylphenyl group and an alkyl group functioned as low molecular weight gelators for various organic solvents and ionic liquids. Urea derivatives with long alkyl chains were effective for the gelation of polar solvents. However, they were not suitable for the gelation of non‐polar solvents, whereas urea derivatives with short alkyl chains were effective. Ionic liquids were similar to polar solvents in that urea derivatives with long alkyl chains were the most effective gelators. The physical properties of the formed supramolecular gels were analyzed by dynamic viscoelasticity measurements using a rheometer. [ABSTRACT FROM AUTHOR]

A novel method of large-scale synthesis of alpha,beta-unsaturated ketones through the use of Lewis acid-promoted coupling reactions of acid chlorides was designed. The procedure featured the reaction of organoaluminum and organozinc reagents in the induction of coupling reactions. A distinctive approach was the elimination of hydrogen chloride from the chloro ketone to (E)-pent-3-en-2-one. The stability afforded by the presence of dialkylzinc was found to be advantageous for the procedure.