Tandem-type Pd(II)-catalyzed oxidative Heck reaction/intramolecular C-H amidation sequence: a novel route to 4-aryl-2-quinolinones

A novel catalytic method for synthesizing 4-aryl-2-quinolinones is reported. The process involves two mechanistically independent, sequential Pd(II)-catalyzed reactions--the oxidative Heck reaction and the intramolecular C-H amidation--both of which smoothly proceed in the presence of a single catalytic system in a one-pot manner.     

Dependence of the resultant Seebeck coefficient on the thickness of Bi<Subscript>0.88</Subscript>Sb<Subscript>0.12</Subscript> alloy in welded M/Bi–Sb/M (M = Cu and Ni) composites

The local Seebeck coefficient α _L and the resultant Seebeck coefficient α _R of M/Bi_0.88Sb_0.12/M (M = Cu and Ni) composites with different thicknesses t _Bi–Sb of Bi–Sb alloy were measured as functions of z and T, where T is the absolute temperature, z is the distance from a center of Bi–Sb alloy to the middle point of two probes and α _L and α _R were measured using two probes separated by s=1.0 mm and s=t _Bi−Sb+0.1 mm, respectively. As a result, α _L was enhanced extremely at the position of 0.2–0.3 mm away from the interfaces, while the local temperature along a composite varies linearly with changes in z within Bi–Sb alloy. The local maximum of α _R at 344 K appeared at t _Bi−Sb≈0.9 mm, so that it is expected to increase up to −167 μV/K at t _Bi−Sb=0.87 mm from the expression fitted well to the experimental data, which is 2.1 times as large as the intrinsic α at 344 K of Bi–Sb alloy. Such a local enhancement in α _L would probably be caused by a temperature gradient across the depletion layer formed at the interface. The thermoelectric figure of merit ZT of a composite with an optimum t _Bi−Sb of 0.87 mm is expected to reach the large value of 0.98 at 344 K, which corresponds to 4.5 times as high a value as ZT=0.22 at 344 K of Bi–Sb alloy. It is thus considered that the increase in α _L at the interface is available as a useful mean of further increase in ZT of thermoelectric devices.     

High thermal conductivity of polymerizable liquid‐crystal acrylic film having a twisted molecular orientation

The aligned films, the homogeneous film, the 90°‐twisted film and the 180°‐twisted film, have been prepared by immobilizing the polymerizable liquid crystals under the UV irradiation. The relation between the thermal conductivity and the aligned molecular direction of the films was investigated. It is indicated that the additional thermal transmission effect, which the increase of the thermal conductivity may be induced, would exist in the twisted films. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1419–1425, 2006     

Medicinal Flowers. Part 29. Acylated Oleanane‐Type Triterpene Bisdesmosides: Perennisaponins G,H, I,J, K,L, and M with Pancreatic Lipase Inhibitory Activity from the Flowers of Bellis perennis

The MeOH extract from the flowers of Bellis perennis was found to show pancreatic‐lipase inhibitory activity (IC₅₀ 455 μg/ml). From the extract, seven new triterpene saponins named perennisaponins G ( 1 ; IC₅₀ 163 μM ), H ( 2 ; 137 μM ), I ( 3 ; 147 μM ), J ( 4 ; 148 μM ), K ( 5 ; 223 μM ), L ( 6 ; 81.4 μM ), and M ( 7 ; 195 μM ) were isolated as pancreatic lipase inhibitors. The stereostructures of 1 – 7 were elucidated on the basis of chemical and spectroscopic evidence.     

Variable on-demand release function of magnetoresponsive hybrid capsules

Magnetoresponsive hybrid capsules formed with polyelectrolytes, amphiphile bilayers and Fe(3)O(4) nanoparticles were fabricated by a colloid-templating technique. Melamine-formaldehyde (MF) core particles with polyelectrolyte multilayer shell were prepared by layer-by-layer assembly. Fe(3)O(4) nanoparticles were additionally deposited on the capsular surface. Hollow capsules were obtained by the removal of the MF core particles. Amphiphile bilayer was finally coated on the obtained hollow capsules. The deposition amount of the Fe(3)O(4) nanoparticles is variable by changing the concentration of Fe(3)O(4) dispersion using for preparation of capsules. Encapsulated dyes were released on-demand by irradiation with an alternating magnetic field, due to a phase transition in the amphiphile membrane, induced by heating of the magnetic nanoparticles. The release rate of the hybrid capsules was controllable through controlling the deposition amount of Fe(3)O(4) nanoparticles on the capsules.     

Cytotoxicological aspects of organic arsenic compounds contained in marine products using the mammalian cell culture technique

Arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethylarsonium iodide, which are contained in marine fishery products, were examined for their potencies on cell growth inhibition, chromosomal aberration and sister chromatid exchange (SCE). Arseno- betaine, the major water-soluble organic arsenic compound in marine animals, exhibited very low cytotoxicity towards mammalian cells. This compound showed no cell growth inhibition at a concentration of 10 mg cm⁻³ and the cytotoxicity was lower than 1/14 000th of that of sodium arsenite and 1/1600th of that of sodium arsenate towards BALB/c 3T3 cells. The chromosomal aberrations caused by arsenobetaine at a concentration of 10 mg cm⁻³ consisted mainly of chromatid gaps and chromatid breaks, but in this concentration chromosomal breakage owing to its osmotic pressure is likely to be considerable. No SCE was observed at a concentration of 1 mg cm⁻³. Arsenocholine and trimethylarsine oxide also showed no cell growth inhibited at a concentration of 10 mg cm⁻³. However, tetramethylarsonium iodide inhibition the growth of BALB/c 3T3 at a concentration of 8 mg cm⁻³. These compounds exhibited a low ability to induce chromosomal aberrations at a concentration range of 2–10 mg cm⁻³ and no SCE was observed at a concentration of 1.0 mg cm⁻³. These results suggested that the major and minor organic arsenic compounds contained in marine fishery products are much less cytotoxic inorganic arsenic, methylarsonic acid and dimethylarsinic acid. © 1998 John Wiley & Sons, Ltd.     

Preparation of J-aggregate liposome dispersions and their chromic transformation

We report the preparation of aqueous liposome dispersions of J-aggregates formed by the amphiphilic merocyanine dye (MD). A series of liposome-forming lipids were dispersed together with MD J-aggregates at different molar ratios of MD to lipid. The MD J-aggregate dispersions prepared with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at the MD to DMPC ratio of 0.16 exhibit good dispersibility; that is, they can be readily redispersed without any flocculation even after their precipitation. By use of different counterions for the MD molecules, two types of J-aggregate dispersions, one that exhibits an absorption band (J-band) at 635 nm (type I) and the other at 600 nm (type II), were obtained. As an example of the use of MD J-aggregates liposome dispersions, the thermochromic transformation of MD J-aggregates was demonstrated. When the dispersions are heated, J-aggregates of type I transformed into type II at a certain temperature (T(disp)). The parameters that control the speed of the transformation and the value of T(disp) were determined.     

Pincer-type bis(carbene)-derived complexes of nickel(II): Synthesis, structure, and catalytic activity

Air- and moisture-stable NHC (N-heterocyclic carbene)-derived CNC-type pincer complexes of nickel(II) 4a-d were successfully synthesized, and their structures were fully characterized using X-ray crystallography and analytical and spectroscopic methods. These complexes exhibit a high catalytic activity for the Suzuki-Miyaura coupling reaction of aryl bromides and chlorides with aryl- and alkenylboronic acids, providing an array of biphenyls and stilbenes generally in high yields.     

Liquid–Liquid Equilibria for Extraction of Citrus Essential Oil Using Ionic Liquids

The object of this study was to measure the liquid–liquid equilibria (LLE) data of binary mixtures containing ionic liquids and citrus essential oil. We investigated linalool as the citrus essential oil, and 1-alkyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C _n MIM]⁺[TFSI]^?) as the ionic liquid. Firstly, the experimental apparatus and procedure for the LLE measurement of mixtures containing ionic liquids were verified by measuring the LLE of the binary mixture 1-hexyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C₆MIM]⁺[TFSI]^?) + 1-hexanol as a reference test system recommended by Marsh et al. (Pure Appl Chem 81:781–789, 2009). Next, the LLE data for IL + linalool were obtained, and the LLE data of two binary mixtures 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C₄MIM]⁺[TFSI]^?) or [C₆MIM]⁺[TFSI]^? + linalool were determined. The experimental LLE data were satisfactorily represented by the non-random two-liquid model.     

Time‐Dependent Emission Enhancement of the Ethynylpyrene‐o‐Carborane Dyad and Its Application as a Luminescent Color Sensor for Evaluating Water Contents in Organic Solvents

The time‐dependent emission enhancement (TDEE) phenomena of the 1‐(o‐carboran‐1‐yl)ethynylpyrene dyad were reported. It was found that the emission intensity from the dyad increased in tetrahydrofuran (THF), acetone and dichloromethane with increasing incubation time. From the mechanistic studies, it was suggested that agglomeration of the dyad gradually proceeded in these media, followed by expression of excimer luminescence. Additionally, it was shown that the rates of TDEE of the dyad were sensitively accelerated in the presence of a trace amount of water. Based on this fact, a detection system for water contents in acetone was constructed. Before and after incubation for 96 h at room temperature, time courses of changes in optical properties were monitored. Finally, water contents in acetone can be estimated by the degrees of TDEE and emission color changes in the range from 0.1 wt % to 2.0 wt % and from 2.0 wt % to 20 wt %, respectively.