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Abstract: No catalyst pre-activation, no suicide alkyne, and no additive is required in an extremely simple procedure for the metathesis of alkyl-, alkenyl-, and aryl-propynes: just mix Mo(CO)6, p-chlorophenol, and the alkyne in 1,2-dichloroethane, heat at 85°C for 9–24h, and the symmetrical alkyne is produced in ca. 95% yield. [Copyright &y& Elsevier]

Three new series of phosphorus-containing dendrimers are described. Their solubility depends on the type of end groups they bear. Perfluoroalkyl chains give dendrimers soluble in chlorofluorocarbons, whereas guanidinium and pyridinium derivatives give water-soluble compounds. The thermal stability of these compounds, as well as of 19 other dendrimers of various generations, having various cores, or various end groups, or branching points is studied. The main feature of this study is that the internal structure of these dendrimers is thermally stable at least up to 376°C. The number of the generation has practically no influence, whereas the principal criterion influencing the thermal stability is the type of end groups. The water-soluble cationic dendrimers are the least stable, but even those are stable up to 225°C. For most of these dendrimers, an important percentage of mass (around 50%) is retained even at a temperature as high as 1000°C. In the best case, up to 70% of the initial mass is retained at 1000°C. [Copyright &y& Elsevier]

The preparation of a triptych nanomaterial made of TiO 2 nanoparticles as semiconductor, Ag plasmonic nanoparticles and a carbo -benzene macrocyclic molecule as photosensitizer is described, and used to produce hydrogen by photo-reduction of pure deionized water under 2.2 bar argon pressure without any electrical input. Silver nanoparticles (~5 nm) are grafted onto the surface of commercial TiO 2 nanoparticles (~23 nm) by a photo-deposition process using an original silver amidinate precursor. The thickness of the photosensitive layer (2 nm), which completes the assembly, plays a crucial role in the efficiency and robustness of the triptych nanocatalyst. Thanks to the organic layer reorganization during the first ~24 h of irradiation, it leads to an enhancement of the hydrogen production rate up to 5 times. The amount of silver and carbo -benzene are optimized, along with the mass concentration of nanocatalyst in water and the pH of the aqueous medium, to allow reaching a hydrogen production rate of 22.1 μmol·h−1·g photocatalyst −1. Image 1 • Triptych nanocatalyst TiO 2 /Cbz2%/Ag3% for green photocatalytic hydrogen production. • Reorganization of the photosensitive layer during UV–visible irradiation. • The hydrogen production rate is increased by 5 time after reorganization. • H 2 production rate of 22.1 μmol·h−1·g−1 under 2.2 bar argon gas in pure water. • Original and valuable data for benchmarking purposes are provided. [ABSTRACT FROM AUTHOR]

This work proposes a new efficient, long-lasting scalable and low-cost triptych photocatalyst by assembling a semiconductor thin film (planar anatase TiO 2), a photosensitive molecule of the carbo -benzene (Cbz) family and plasmonic Ag nanoparticles with exquisite degree of intimacy with the semiconductor. Under simulated sunlight conditions over 48 h, the triptych TiO 2 /Ag/Cbz photocatalyst allows a hydrogen production rate of 0.18 mmol g photocatalyst −1 h−1 in conditions of applicative pressure (2.2 bars) and temperature (ambient) suitable for commercial applications. A ternary synergy (~33%) for hydrogen production is clearly evidenced with the triptych material in comparison with the diptych counterpart. The role of each component (TiO 2 , Ag and Cbz) on the H 2 production is investigated systematically by discriminating the light absorption from the different materials and interfaces. We show how to achieve an efficient vertical Schottky junction between Ag nanoparticles and the TiO 2 substrate that is demonstrated to be of crucial importance in the water-splitting process. • TiO 2 planar photocatalyst with Ag nanoparticles and Carbo- benzene photosensitizer. • Design of a new efficient, long-lasting and low-cost triptych photocatalyst. • Hydrogen production under ambient and pressurized conditions. • New general technological pathway to manufacture of triptych photocatalyst. • Original nanostructure and valuable data for benchmarking purposes are provided. [ABSTRACT FROM AUTHOR]

Ethynylogation of a chiral lipidic dialkynylcarbinol (DAC), identified as a lead for cytotoxicity against HCT116 cancer cells, is shown to typify the butadiynyl-alkynylcarbinol (BAC) unit as a new pharmacophore. The enantiomers of the internal BAC have been synthesized with 72–75% yield and 85% ee through the use of a modified Carreira reaction shown here for the first time to be compatible with butadiyne and ynal substrates. One enantiomer of the internal BAC could be characterized by X-ray crystallography. In this particular case, the ‘DAC to BAC’ ethynylogation results in a slight enhancement of the eutomer potency with a preserved vanishing eudismic ratio (IC 50 values from 102±14 nM to 42±12 nM for the (+) enantiomers). [ABSTRACT FROM AUTHOR]

Chiral lipidic dialkynylcarbinols (DACs), recently highlighted as antitumoral pharmacophores, have been conjugated to difluoroboron-dipyrromethene (bodipy), 7-hydroxy-coumarine, and 7-nitro-benzoxadiazole (NBD) fluorophore motifs through triazole clips. The labeled lipids preserve cytotoxic activity against HCT116 cells, and fluorescence microscopy of the stained cells showed clear signals in the intra-cellular membrane system. While the bodipy conjugate also labels lipid droplets very brightly, as expected, the coumarine and NBD probes appear as promising specific tools for the identification of the intra-cellular targets of DACs’ cytotoxicity. [ABSTRACT FROM AUTHOR]

The chiral alkynylcarbinol motif typically found in natural marine products, has been the subject of intense research activity for its pharmacophoric properties, in particular cytotoxicity against tumor cell lines. In a chemical synthesis-driven four-parameter structure–activity relationship (SAR) study from the ( S , E )-eicos-4-en-1-yl-3-ol natural reference 1 , the ( S )-dialkynylcarbinol unit of the non-natural dehydro derivative 2 emerged as an unprecedented anti-tumoral pharmacophore. An extended study of lipidic alkynylcarbinol pharmacophores is presented, addressing additional structural parameters: Z→E isomerization of the alkenyl carbinol substituent of 1 , variation of the lipidic chain length of 2 (C 3n , n =3, 4, 6), oxidation or substitution of the carbinol unit of 2 (to ketone, tertiary methylcarbinol, or methylether), cyclomethylenation of the double bond of 1 . The synthesis of these analogues is described, including the preparation of enantio-enriched chiral alkynylcarbinol derivatives using a modified Carreira procedure for Zn-mediated addition of (trialkylsilyl)acetylene substrates to ynals in the presence of (−)- or (+)- N -methylephedrine. Preliminary cytotoxicity evaluation of 12 new products against the HCT 116 tumor cell line are finally reported and the results compared with those obtained for 1 and 2 . These observations support and refine the relevance of the pharmacophoric character of secondary DAC units. [ABSTRACT FROM AUTHOR]

Herein, the optical properties of thiophene-functionalized quadrupolar carbo -benzenes and a benzenic parent, of generic structure Th–C C–[core]–C C–Th, Th = R 2 C 4 HS, are comparatively investigated. Beyond the previously unknown dioctylthienylethynylbenzene (core = p -C 6 H 4 , R = n Oct), two bis-dialkylthienylethynyl- carbo -benzenes (core = C 18 Ph 4 , R = n Oct, n Bu) are envisaged for the unique " carbo -aromatic" character of the C 18 macrocycle. The three targets were synthesized from the corresponding ethynylthiophenes in 47, 20 and 10% yield, respectively, then characterized by classical methods such as NMR spectroscopy, and X-ray crystallography for one of the carbo -benzenes. Regarding linear and nonlinear optical properties, our results show that the carbo -merization induces a significant shift to lower energies of the one-photon electronic excitations accompanied by an 8-fold increase of the molar extinction coefficient compared to the parent molecule. Intriguingly, these excitations lead to a broad band of photoluminescence comprising decay transitions of the type S 1 → S 0 but also of the type S 2 → S 0. This phenomenon of emission from higher excited states, which is contrary to Kasha's rule, is assigned to - or revealed by - a reduction of the internal conversion efficiency between S 2 and S 1. Two-photon induced transitions are also enhanced, the two-photon absorption cross-section (σ 2PA) being in average five times larger for the carbo -benzenes than for their benzene parent in the wavelength range 650–950 nm, with a maximum of σ 2PA = 1430 GM (1 GM = 10−50 cm4 s/photon). Beyond a moderate nonlinearity, this comparative study provides quantitative insights about the way carbo -merization or insertion of a π-conjugated macrocycle between chromophoric functions (here thiophene rings) can tune optical properties of organic molecules. The optical properties of the bis-dialkylthienylethynyl- carbo -benzenes are also discussed in regard of recent reports on organic chromophores based on other types of π-conjugated macrocyclic cores. Image 1 • A full core-carbo-meric effect analysis on optical properties is reported for the first time. • Enhancement of 2 PA in a carbo -benzene is demonstrated versus its benzenic parent. • Anomalous luminescence is observed in the carbo- benzene due to simultaneous radiative decays from different excited states. • Janus aromatic softness in a "super-soft" chromophore: atom-governed in thiophene (S), size-governed in carbo-benzene (C18). [ABSTRACT FROM AUTHOR]

New aza-BODIPYs with significant bathochromic shifts in their UV–vis absorption spectrum were synthesized by the installation of 1-ethyl-indol-3-yl moieties at the 1,7-positions of the aza-BODIPY core bearing 4-substituted phenyl or thien-2-yl groups at the 3,5-positions. The compounds described herein show strong NIR absorptions up to 779 nm, and emissions up to 805 nm in chloroform solution, and present large molar extinction coefficients. The absorption and emission bands of aza–BODIPYs were significantly red-shifted, by ca 100 nm, relative to the 3,5-dianisyl-1,7-diphenyl aza-BODIPY. TD-DFT calculations indicate an effective electronic conjugation between the aza-BODIPY core and the substituents. Absorption of the studied aza-BODIPY derivatives corresponds to a charge transfer from donor substituents toward the boron-centered core. Moreover, computational results show that all the compounds present HOMO–LUMO band gap values that are in the organic semiconductor range. [Display omitted] • A series of new aza-BODIPYs with 1-ethyl-indol-3-yl substituents were synthesized. • These dyes show strong NIR absorptions up to 779 nm, and emissions up to 805 nm in chloroform solution. • DFT-calculated and optical band gap values are found to lie in the organic semiconductor range. [ABSTRACT FROM AUTHOR]

[Display omitted] • Alkynylcarbinols acetates were resolved by lipase-mediated kinetic resolution (LMKR). • Three lipidic alkynylcarbinols (LACs) and a dialkynylcarbinol (DAC) were resolved. • (R)-Alcohols and (S)-acetates were obtained in enantiomeric/enantiorich forms. • Immobilized C. antarctica B lipase was a robust biocatalyst in the LMKR of the LACs. • Immobilized T. lanuginosus lipase provided optimal LMKR of the DAC C 5 synthon. Lipase-mediated kinetic resolution (LMKR) of three racemic lipidic alkynylcarbinol (LAC) acetates, rac -heptadeca-1,4-diyn-3-yl acetate (rac - 2 -Ac), rac- heptadeca-1,4,6-triyn-3-yl acetate (rac - 3 -Ac) and rac- heptadeca-1-yn-3yl acetate (rac - 4 -Ac), besides the versatile C 5 synthon dialkynylcarbinol (DAC) acetate, rac -(triisopropylsilyl)penta-1,4-diyn-3-yl acetate (rac - 5), was studied. CAL-B immobilized on acrylic resin was investigated as catalyst on LMKR of rac - 2 - 5 -Ac. Fourteen commercial lipases (immobilized and free forms), besides one esterase, were also investigated on the LMKR of rac - 5 -Ac. After investigation of reaction parameters, optimal conditions were established for each compound, yielding both (R)- and (S)-alcohols in 50 % conversions, enantioselectivities (E) >200 and high e.e. values [(R)- 2 and (S)- 2 -Ac, e.e. >99 %; (R)- 3 and (S)- 3 -Ac, e.e. 98 %; (R)- 4 and (S)- 4 -Ac, e.e. 96 %; (R)- 5 and (S)- 5 -Ac, e.e. >99 %]. Except for rac - 5 -Ac that had Thermomyces lanuginosus immobilized on immobead-150 as best catalyst, CAL-B was the most efficient lipase on LMKR of rac - 2 - 4 -Ac. (S)-Alcohols were obtained by lipase-mediated hydrolysis of (S)-acetate compounds, using CAL-B for (S)- 4 -Ac (57.5 % yield and e.e. 96 %) and lipase from Candida rugosa for (S)- 5 -Ac (53 % yield and e.e. >99 %). [ABSTRACT FROM AUTHOR]