Total synthesis of cis-solamin and its inhibitory action with bovine heart mitochondrial complex I

A convergent total synthesis of cis-solamin (1a) and its diastereomer (1b) was accomplished. A key reaction of this approach was the use of VO(acac)₂-catalyzed diastereoselective epoxidation of (Z)-bis-homoallylic alcohol 3 followed by spontaneous cyclization for the cis-THF ring formation. By comparison of the optical rotation of the two possible diastereomers, it is suggested that the absolute configuration of natural cis-solamin is 1a. Inhibitory action of synthetic 1a and 1b with bovine heart mitochondrial complex I are reported.     

Stannyl radical addition-cyclization of oxime ethers connected with olefins

Stannyl radical addition-cyclization of oxime ethers connected with olefin moieties was studied. The radical reactions proceeded effectively by the use of triethylborane as a radical initiator to provide the functionalized pyrrolidines via a carbon-carbon bond-forming process.     

Synthesis and structure of 16 pi octaalkyltetraphenylporphyrins

The oxidized octaethyltetraphenylporphyrin (1, OETPP) and the corresponding newly prepared octaisobutyltetraphenylporphyrin (3, OisoBuTPP) could be isolated from the reaction of OETPPLi2 (or OisoBuTPPLi2) with SOCl2. The X-ray analysis and the characteristic UV-vis spectra of 1 and 3 revealed that these are the first examples of 16 pi nonaromatic porphyrins.     

Bromination by means of sodium monobromoisocyanurate (SMBI)

A variety of aromatic compounds with both activating and deactivating substituents were brominated with sodium monobromoisocyanurate (SMBI) 1, diethyl ether, diethyl ether-methanesulfonic acid, trifluoroacetic acid, or sulfuric acid were employed as solvents. Thus nitrobenzene was conveniently brominated in sulfuric acid, benzene was readily monobrominated in diethyl ether-methanesulfonic acid, and phenol was selectively brominated at the ortho position under mild conditions in refluxing diethyl ether. With substituents that are easily protonated, trifluoroacetic acid may be employed as solvent in the reaction with 1, in contrast NBS was ineffective in trifluoroacetic acid. This renders 1 a superior reagent relative to NBS. In addition to aromatics, alkenes, ketones and esters were also brominated with 1. Diethyl malonate was brominated with 1 and then subjected to a Bingel reaction with NaH to afford the desired methanofullerene in reasonable yield.     

Enantioselectively catalyzed oxidation of 3,4-dihydroxy-l-phenylalanine by N-lauroyl L or D-histidine-Cu(II) complex in CTABr micelles.

In order to investigate the enzyme model reaction the oxidation of 3,4-dihydihydroxy-L-phenylalanine(L-DOPA) was carried out using optically active catalyst, N-lauroyl L or D-histidine-Cu(II) complex(L or D-LauHis-Cu(II)), showing appreciable enantioselectivity in the presence of the mixed micelles with CTABr.     

Production of poly(methyl methacrylate) particles by dispersion polymerization with mercaptopropyl terminated poly(dimethylsiloxane) stabilizer in supercritical carbon dioxide

Poly(methyl methacrylate) (PMMA) particles were produced by dispersion polymerization of methyl methacrylate in the presence of mercaptopropyl terminated poly(dimethylsiloxane) (MP-PDMS) in supercritical carbon dioxide at about 30 MPa for 24 h at 65 °C. The particle diameter could be controlled in a size range of submicron to micron by varying MP-PDMS concentration. The MP-PDMS worked as not only a chain transfer agent but also a colloidal stabilizer, which was named tran stab.Part CCLI of the series Studies on suspension and emulsion     

New alkaline earth aluminum hydride with one-dimensional zigzag chains of [AlH6]: synthesis and crystal structure of BaAlH5

The title hydride and its deuteride were successfully synthesized. The crystal structure of the deuteride was determined by time-of-flight neutron powder diffraction. BaAlD(5) crystallizes with a new orthorhombic structure in space group Pna2(1) (No. 33), cell parameters a = 9.194(1) A, b = 7.0403(9) A, and c = 5.1061(6) A, Z = 4. BaAlH(5) is the first example that contains one-dimensional zigzag chains of [AlH(6)] along the crystallographic c axis.     

Application of europium(III) extraction with organophosphinic acid to liquid membrane transport

The extraction behavior of Eu(III) has been studied using di(2,4,4-trimethylpentyl)phosphinic acid (DTMPPA, HA) in kerosene. Europium was extracted as Eu(HA₂)₃ with the extraction constant of 2.0·10^–3. This extraction system was applied to the transport of Eu(III) across a DTMPPA liquid membrane supported on porous polytetrafluoroethylene. Europium was quantitatively moved through the liquid membrane containing 0.1M (HA)₂ as a mobile carrier from the feed solution of pH above 3 into the product solution of 0.1M HNO₃, yielding a concentration factor of ten. The transport rate increased with increasing pH and DTMPPA concentration.     

Single-bubble sonochemiluminescence in aqueous luminol solutions

Sonochemiluminescence (SCL) of luminol due to a single bubble is studied through spectral measurement. No SCL was observed from a stable single bubble that emitted high-intensity sonoluminescence (SL). In contrast, SCL was observed under conditions of an unstable dancing bubble, where a bubble grows and ejects tiny bubbles, making it "dance" by counteraction. Furthermore, SCL was observed from dancing bubbles even when SL was not observed, depending on the dissolved gas content. The instability of bubble collapse is the key parameter governing SCL.