Syntheses and thermal reactions of 2-alkyl(or aryl)-1-benzoyl-3,4-dihydro-2-thianaphthalenes

1-Benzoyl-2-methy1-3,4-dihydro-2-thianaphthalene ($\text{4a}$) underwent novel intermolecular 1,4-rearrangement in refluxing toluene to give an enol ether $\text{5a}$, while rearrangement of 2-phenyl derivative $\text{4e}$ proceeded intramolecularly in refluxing xylene to afford a 1,4-rearranged enol ether $\text{5b}$. On the other hand, ylides $\text{4a–e}$ were refluxed in alcohols to afford some ring-opened products $\text{10–12}$.     

A quantum chemical study of interchain hopping model of negatively charged solitons in polyacetylene

Phonon-assisted interchain hopping of negatively charged solitons in polyacetylene has been studied using a local chemical reaction model CH + CH₄ → CH₄ + CH. Quantum chemical characteristics of the electron transfer process have been analyzed in terms of the dynamic electron density and the mutual polarization moment. The CH stretching vibrational motion of CH₄, which is a local model of the sp³ defect, has been found to play a significant role for the electron transfer. The excitation of the corresponding vibrational mode of the sp³ defect would promote the interchain hopping of the charged soliton. The electron transfer process has also been studied in terms of the “regional” density functional theory. It has been shown that the driving force of the electron transfer is represented by the regional chemical potentials.     

Palladium-catalyzed oxidation of alcohols via their allyl carbonates under neutral conditions

Treatment of alkyl allyl carbonates derived from various alcohols with a palladium catalyst in MeCN affords ketones and aldehydes in high yields. This new method of oxidation of alcohols can be applied to various alcohols except simple primary alcohols.     

The study of electron beam flue gas treatment for coal-fired thermal plant in Japan

The fundamental research work with simulated coal-fired flue gas was performed in JAERI to get basic data for electron beam treatment of flue gas from thermal power plants in Japan. The standard condition of the experiments was set to be the same as that of next large scale pilot test in Nagoya. The concentrations of NO_x and SO_x were 225 ppm and 800 ppm, respectively. The temperature of the system was 65°C. The effect of multiple irradiation was observed for NO_x removal. The target SO_x and NO_x removals (94% and 80%, respectively) with low NH₃ leakage (less than 10 ppm) were achieved at 9 kGy irradiation with 0.9 NH₃ stoichiometry during 7 hours continuous operation. The facility for the pilot plant (12,000 Nm³/hr) has just built at the site of Shin-Nagoya power plant of Chubu Electric Power Company and will be started in full operation in November 1992.     

Use of allyl, 2-tetrahydrofuryl, and 2-tetrahydropyranyl ethers as useful C3-, C4-, and C5-carbon sources: palladium-catalyzed allylation of aldehydes

Palladium-diethylzinc or palladium-triethylborane catalytically promotes self-allylation of 2-(allyloxy)tetrahydrofurans, 2-(allyloxy)tetrahydropyrans, and their hydroxy derivatives on the rings (ribose, glucose, mannose, deoxyribose, deoxyglucose). All the reactions proceed at room temperature and provide polyhydroxyl products, sharing a structural motif of a homoallyl alcohol, in good to excellent yields with high levels of stereoselectivity. Useful C3-unit elongation, which makes the best use of an allyl ether as a protecting group and a nucleophilic allylation agent, is demonstrated. Mechanisms for the umpolung reaction (of an allyl ether into an allylic anion) and stereoselectivity associated with allylation of aldehydes are discussed.     

Simultaneous polymerization and formation of polyacetylene film on the surface of concentrated soluble Ziegler-type catalyst solution

A direct method of simultaneously polymerizing and forming acetylene monomer to produce uniformly thin films of polyacetylene was investigated in terms of catalyst system, catalyst concentration, and polymerization temperature. The best catalyst was a Ti(OC₄H₉)₄–Al(C₂H₅)₃ system (Al/Ti = 3–4) and the critical concentration was 3 mmole/l. of Ti(OC₄H₉)₄. Below the critical concentration, only a solid or a powder was obtained. The configuration of the polymers obtained depends strongly upon the polymerization temperature. Thus an all-cis polymer was obtained at temperatures lower than ?78°C, whereas an all-trans polymer resulted at temperatures higher than 150°C. Observations either in an electron microscope by direct transmission or in a scanning electron microscope showed that the film is composed of an accumulation of fibrils about 200–300 Å in width and of indefinite length.     

Effects of Aerosol-OT reversed micelles in carbon tetrachloride on acid-base indicator equilibria

ApparentpK _a values of thymol blue solubilized in Aerosol-OT reversed micelles in carbon tetrachloride at 25 °C were determined spectrophotometrically. The effects of the Aerosol-OT concentration and the (water)/(surfactant)R ratio were investigated. The apparentpK _a values increase as a function of increasing (R). All the measuredpK _a values are less than that in water. The decrease ranges from 1.23 units (detergent=0.4 M,R=1.39) to 0.42 units (Aerosol-OT=0.6 M,R=9,25). These results are rationalized in terms of decreased hydronium ion activity in the micellar core due to its binding to the detergent SO₃ ^? groups.     

Novel quinazoline ring synthesis by cycloaddition of N-arylketenimines with N,N-disubstituted cyanamides

The reaction of N-aryl-substituted ketenimines with N,N-disubstituted cyanamides or (MeS)2C=N-CN under high pressure afforded 4-(N,N-disubstituted amino) or 4-(MeS)2C=N-substituted quinazoline derivatives, respectively. These products were formed by [4+2] cycloaddition between the aza-diene moieties of the N-arylsubstituted ketenimines and cyano groups. A 4-(unsubstituted amino)quinazoline derivative was synthesized by hydrolysis of the latter product.     

Synthesis and analgesic activity of novel heterocycles, [1]benzothiopyrano[3,4-b]pyrrole derivatives

In order to develop analgesic compounds possessing a sulfur atom in the alicyclic ring, novel cis-fused heterocycles, [1]benzothiopyrano[3,4-b]pyrrole derivatives (II) were synthesized via a unique cyclization reaction starting from 4-(4-methoxyphenylthio)-2-butanone (1) or 6-methoxy-3,4-dihydro-2H-1-benzothiopyran-4-one (7). The analgesic effects of benzothiopyranopyrroles (16, 18) were measured by means of the writhing test. The phenolic derivative 18 completely inhibited the appearance of writhing at the dose of 50 mg/kg, but the methoxy derivative 16 had no analgesic effect.     

Cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic and benzylic Grignard reagents and their application to tandem radical cyclization/cross-coupling reactions

Details of cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic Grignard reagents are disclosed. A combination of cobalt(II) chloride and 1,2-bis(diphenylphosphino)ethane (DPPE) or 1,3-bis(diphenylphosphino)propane (DPPP) is suitable as a precatalyst and allows secondary and tertiary alkyl halides--as well as primary ones--to be employed as coupling partners for allyl Grignard reagents. The reaction offers a facile synthesis of quaternary carbon centers, which has practically never been possible with palladium, nickel, and copper catalysts. Benzyl, methallyl, and crotyl Grignard reagents can all couple with alkyl halides. The benzylation definitely requires DPPE or DPPP as a ligand. The reaction mechanism should include the generation of an alkyl radical from the parent alkyl halide. The mechanism can be interpreted in terms of a tandem radical cyclization/cross-coupling reaction. In addition, serendipitous tandem radical cyclization/cyclopropanation/carbonyl allylation of 5-alkoxy-6-halo-4-oxa-1-hexene derivatives is also described. The intermediacy of a carbon-centered radical results in the loss of the original stereochemistry of the parent alkyl halides, creating the potential for asymmetric cross-coupling of racemic alkyl halides.