Synthesis of Heterocyclic Compounds Using Amidines as Their Ene-1,1-diamine Tautomers,IV: Synthesis of N-Bridged Heterocycles 1,2,3,4-Tetrahydropyrido[1,2-a]pyrimidin-6-ones and Methyl 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrimidin-7-ylideneacetates

2-Benzyl-1,4,5,6-tetrahydropyrimidines 1 (as ene-1,1-diamine N,C-tautomers) in diglyme reacted with ethyl benzoylacetate at 160 °C in an oil bath to give 1,2,3,4-tetrahydropyrido[1,2-a]pyrimidin-6-ones 3 and with dimethyl acetylenedicarboxylate in methanol at room temperature, leading to methyl 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrimidin-7-ylideneacetates 5, respectively.      

A cinnamic acid-type photo-cleavable surfactant

We have developed a novel cinnamic acid-type photo-cleavable surfactant. This surfactant experiences photo-cleavage through UV-induced cyclization in aqueous solutions. The photo-cleavage not only reduces its capabilities as a surfactant but also yields two functional materials including a coumarin derivative and an aminated polyoxyethylene compound. This means that the photo-cleavable surfactant synthesized in this study is a photo-responsive function-exchangeable material. In our current study, we have characterized the photo-cleavable behavior that occurs in aqueous solutions and a resulting change in interfacial properties. The photo-cleavage induces an increased interfacial tension of a squalane/water interface and a decreased solubilization capability of the surfactant micelles.     

Periodic Structure in Pblg-Dioxane System Under Electric Field

Periodic patterns were observed in PBLG-dioxane system under an electric field which was higher than the threshold field of the isotropic-nematic transition. The size of the well oriented zone became larger with the field strength, while the lattice constant of the pattern was independent of the electric field.     

Bench-Stable Electrophilic Fluorinating Reagents for Highly Selective Mono- and Difluorination of Silyl Enol Ethers

Efficient methods for the synthesis of fluorinated compounds have been intensively studied, recently. Development of practical fluorinating reagents is indispensable for this purpose. Herein, bench-stable electrophilic fluorinating reagents were synthesized as N-fluorobenzenesulfonimide (NFSI) substitutes. Reagents obtained by replacing one of the NFSI sulfonyl groups with an acyl group led to the highly selective monofluorination of silyl enol ethers with suppression of undesired overreaction, that is, difluorination. On the other hand, reagents bearing electron-withdrawing substituents at NFSI benzenesulfonyl groups efficiently facilitated the difluorination of silyl enol ethers under base-free conditions. Thus, both mono- and difluorinated target materials were prepared from the same substrate.     

On boundary layers

The concept of boundary layers, introduced by A. Volberg in [7], is generalized from subsets of the unit disk to subsets of general non-tangentially accessible (NTA) domains. Capacitary conditions of Wiener type series of both necessary and sufficient type for boundary layers are presented and the connection between boundary layers and minimally thin sets is studied.     

Quasiadditivity and measure property of capacity and the tangential boundary behavior of harmonic functions

We show that if a set is dispersely decomposed into subsets, then the capacity of is comparable to the summation of the capacities of the subsets. From this fact it is derived that the Lebesgue measure of a certain expanded set is estimated by the capacity of . These properties hold for classical capacities, -capacities and energy capacities of general kernels. The estimation is applied to the boundary behavior of harmonic functions. We introduce a boundary thin set and show a fine limit type boundary behavior of harmonic functions. We show that a thin set does not meet essentially Nagel-Stein and Nagel-Rudin-Shapiro type approaching regions at almost all bounary points.

     

A new facility for X-ray irradiation and its application

In February 1998, located at Izumiohtsu-Osaka, the West-Japan Irradiation Service Co. Ltd (W-JISCO) opened the new facility “Kansai Electron Beam Irradiation Center” which is the irradiation service center by Electron Beam and X-ray (Bremsstrahlung). The distinguishing feature of this facility is the No. 2 beam line for X-ray conversion.     

Lewis acid-catalyzed [4 + 2] benzannulation between enynal units and enols or enol ethers: novel synthetic tools for polysubstituted aromatic compounds including indole and benzofuran derivatives

The reaction of enynals 1, including o-(alkynyl)benzaldehydes, and carbonyl compounds 2, such as aldehydes and ketones, in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 degrees C gave the functionalized aromatic compounds 3 in high yields. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds 5 afforded the corresponding aromatic compounds 3 in good yields. On the other hand, when the reaction was carried out in the presence of a catalytic amount of Cu(NTf2)2 and 1 equiv of H2O in (CH2Cl)2 at 100 degrees C, the decarbonylated naphthalene products 4 were obtained selectively over 3. Benzofused heteroaromatic compounds, such as indole derivatives 13 and benzofuran derivatives 15, were also synthesized by using the present benzannulation methodology.