Regioselective α-alkylation of ketones with alkyl chlorides and fluorides via highly nucleophilic magnesium enamides

A magnesium enamide derived from N-2-(N′,N′-dimethylamino)ethyl imine reacts with primary and secondary alkyl chlorides and fluorides to give an α-alkylated ketone in good to excellent yields upon hydrolysis of the imine moiety. Reactions of the highly nucleophilic magnesium enamide derived from an unsymmetrical ketone take place regioselectively. In addition, the C-C bond formation is stereospecific: a substantial inversion of stereochemistry at the electrophilic carbon center (Walden inversion) was observed, proving its potential utility for the production of optically active compounds.     

Sterilization of foods with low-energy electrons (“soft-electrons”)

Electrons with an energy of 300 keV or lower were defined as “Soft-electrons”, which showed several advantages over conventional irradiation with gamma-rays or high-energy electrons in decontamination of grains and spices. Energies of electrons necessary to reduce microbial loads to levels lower than 10 CFU/g were 60 keV for brown rice, 75 keV for wheat, 100 keV for white pepper, coriander and basil, 130 keV for buckwheat, 160 keV for rough rice, and 210 keV for black pepper. Electrons with such energies did not significantly influence the quality.     

New High-Performance Catalysts Developed at Mitsui Chemicals for Polyolefins and Organic Synthesis

This contribution reports Mitsui's R&D activities in the field of catalysis technology focusing on molecular catalysts. Examples of the high-performance molecular catalysts developed at Mitsui include bis(phenoxy-imine) group 4 transition metal complex catalysts (FI Catalysts), phosphazene catalysts (PZN catalysts) and b(beta)-ketoiminato Co(II) complex catalysts. Many of the materials stemming from these catalysts were either difficult or impossible to prepare using conventional catalysts.     

A convenient synthesis of 3-formyl-2-oxo-1,2-dihydroquinoxaline chlorophenylhydrazones: Novel tautomeric equilibria between hydrazone imine and diazenyl enamine forms with long-range pSSrototropy

3-Formyl-2-oxo-1,2-dihydroquinoxaline chlorophenylhydrazones 4a-c were synthesized from the reactions of 3-methyl-2-oxo-1,2-dihydroquinoxaline 3 with chlorophenyl diazonium salts, and 4b,c were found to exhibit the tautomeric equilibria between the hydrazone imine and diazenyl enamine forms in the dimethylsulfoxide solutions.     

An ab initio theoretical research on perfluorochemicals as oxygen carriers

In order to elucidate the nature of the interaction force effected in perfluorochemical artificial blood, the basis set dependence of the stabilization energy between a model perfluorochemical and oxygen was investigated in detail. The basis set superposition error was removed in each case. The interaction was estimated to arise from dispersion forces.     

Mesogenicity of Organophosphazenes: The Effect of Phosphazene Rings and Side Groups on the Phase Transition

Cyclotriphosphazene and cyclotetraphosphazene derivatives with mesogenic 4-N-(4-alkoxyphenyl)iminomethyl)phenoxy and 4-(4'-alkoxy)biphenoxy moieties were synthesized. Schiff base moiety has higher mesomorphic stability than that in biphenyl moiety both in cyclotriphosphazene and cyclotetraphosphazene. Cyclotriphosphazenes possess higher thermal stability in the mesomorphic phase than the cyclotetraphosphazenes, suggesting the difference in the molecular structure.     

Fluorescence behavior of individual charge-transfer complexes revealed by single-molecule fluorescence spectroscopy: Influence of the host polymer matrix

Extremely pure polymer matrices were used for elucidating the fluorescence properties of singly isolated charge-transfer (CT) complexes formed between the donor N-ethylcarbazole and the acceptor 1,2,4,5-tetracyanobenzene. Simultaneous measurements (time traces of CT fluorescence intensities and lifetimes) using single-molecule fluorescence spectroscopy showed three patterns: (1) fluctuations in the fluorescence intensities and lifetimes seldom occurred, (2) the fluorescence intensities frequently fluctuated together with the lifetimes, or (3) in addition to the above fluctuations with time, blinking and/or off-states longer than 1 s were observed. For methacrylate polymers, both the degree of fluctuations in the CT fluorescence lifetimes and the percentage of the CT complexes showing off-states increased with the free volume of the host polymers. These results suggest that the degree of fluctuations in the relative geometrical arrangements of the donor and acceptor molecules is related to the availability of space in the host polymer, and that the free volume provides the necessary space for formation of non-fluorescent donor-acceptor geometries of the CT complexes and/or temporal dissociation of the CT complexes. Survival times of the CT fluorescence were also closely related with the free volume of the host polymers.     

End‐functionalization of polystyrene by malto‐oligosaccharide generating aggregation‐tunable polymeric reverse micelle

This article describes that glucose, maltose, maltotriose, maltotetraose, maltopentaose, and maltohexaose ( a , b , c , d , e , and f , respectively) were introduced into the initiating chain‐end of polystyrene (PSt) through the 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated radical polymerization. A series of glycoconjuaged TEMPO‐adducts, 1a–f , was synthesized and used as the initiators for the polymerization of styrene (St) for 6 h at 120 °C to afford the end‐functionalized PSt's with the acetyl saccharides, 2a–f , in the yields of 37–43%. For 2a–f obtained by the polymerizations using the [St]/[ 1 ] of 125, 250, and 500, the number‐average molecular weights determined by size exclusion chromatography (SEC), M_n,SEC's, were 4800–6300, 8800–10,600, and 18,400–25,200, respectively, which fairly agreed with the predicted values. The end‐functionalized PSt's with saccharides, 3a–f , which were obtained from the deacetylation of 2a–f using sodium methoxide in dry THF, formed the polymeric reverse micelles consisting of a saccharide‐core and a PSt‐shell in chloroform and toluene. The static laser light scattering (SLS) measurements provided the average molar mass of the aggregates in toluene, M_w,SLS's, which ranged from 7.50 × 10⁴ to 1.77 × 10⁵ for 3a , from 1.90 × 10⁵ to 4.93 × 10⁵ for 3b , from 4.41 × 10⁵ to 7.21 × 10⁵ for 3c , from 5.85 × 10⁵ to 8.51 × 10⁵ for 3d , from 7.55 × 10⁵ to 8.53 × 10⁵ for 3e , and from 8.54 × 10⁵ to 9.26 × 10⁵ for 3f . The aggregation numbers, N_agg's, which were calculated from the M_w,SLS's, were from 7 to 24 for 3a , from 20 to 37 for 3b , from 34 to 89 for 3c , from 39 to 116 for 3d , from 41 to 145 for 3e , and from 31 to 146 for 3f . It was confirmed that the aggregation property, such as the M_w,SLS or N_agg values, was strongly related to the polymerization degrees of St (DP's) or the number of the glucose residues (n's) for 3a–f . © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4864–4879, 2006     

HPLC retention behaviors of pi-electron rich compounds on Ni2+- and Cu2+-phthalocyanine derivatives bound to silica gels in polar eluents.

The effect of the central metal of columns packed with silica gels binding Ni(2+)- and Cu(2+)-phthalocyanine derivatives (Ni-and Cu-PCS(D)s) on the retention behavior of poly-aromatic-hydrocarbons (PAHs) thereof in a polar eluent was examined. The retention factors of PAHs on the Ni- and Cu-PCS(D)s in 80% methanol showed a good linear correlation. The Cu-PCS(D) column exhibited the pi-pi interactions for PAHs, while the Ni-PCS(D) column exhibited the pi-d interactions for PAHs in addition to the pi-pi interaction for PAHs. Further, an investigation of the retention behavior of anthracene derivatives having different substituents revealed that the Ni- and Cu-PCS(D) columns could recognize the differences of substituents only in a polar eluent.     

Computation of mean-semivariance efficient sets by the Critical Line Algorithm

The general mean-semivariance portfolio optimization problem seeks to determine the efficient frontier by solving a parametric non-quadratic programming problem. In this paper it is shown how to transform this problem into a general mean-variance optimization problem, hence the Critical Line Algorithm is applicable. This paper also discusses how to implement the critical line algorithm to save storage and reduce execution time.