Optical fiber sensor for the measurement of electric field intensity and voltage (OPSEF)

An optical fiber sensor for measuring high electric field intensity and voltage, which utilizes the electro-optic effect of bismuth silicone oxide single crystal, has been developed successfully, and the fundamental characteristics have been evaluated. The electric field intensity distribution inside the coaxial electrodes has been measured with this sensor. The measured results are in agreement with the theoretical values.     

Microscopic evidence for a new type of ordering of spin components in a random mixture with competing magnetic anisotropies

The Mössbauer spectroscopy was applied on a random mixture of two kinds of magnetic ions with competing anisotropies, Fe_1?xCo_xCl₂·2H₂O. The Mössbauer spectra observed in the Co(Fe)-rich antiferromagnetic (AF) phase near the tetracritical point show that, although the m₂(m₁) spin component parallel to the easy axis of pure FeCl₂·2H₂O(CoCl₂·2H₂O) has no long-range order in this phase (from the neutron diffraction experiment), the m₂(m₁) spin component contributes to the magnetic hyperfine field at ⁵⁷Fe nuclei as well as the m₁(m₂) spin component (which has a long-range order). This fact indicates that the m₂(m₁) spin components exists in the Co(Fe)-rich AF phase near the tetra-critical point at least in a time scale of ～ 10^?8s. This result predicts that the antiferromagnetic ordering in the Co(Fe)-rich AF phase is a new type one. The new phase observed in the intermediate concentration region is demonstrated as the “mixed ordering” phase.     

Facile synthesis of 7-10 membered rings by intramolecular condensation using dialkylcarbonate as solvent

A convenient large-scalable synthesis of 1-benzazepines 19 as an important intermediate of CCR5 antagonist, oral HIV-1 therapy, was established. The anilination of o-halogenobenzaldehyde 9 with alkylamino-acid 16 gave o-formylaniline-acid 17. Compound 17 was esterified followed by the improved reaction using the combination of alcoholate and dialkyl carbonate in one-pot, to easily produce 19. Namely, these new processes afforded the desired product 19 in only two steps from the starting materials, as compared with the previous 10 steps. Moreover, these convenient methodologies were applied to other heterocycles to give 8-10 membered rings, such as 1-benzazocine, 1-benzazonine, and 1-benzazecine.     

Tandem Michael addition-carbene insertion reaction of 1-alkynyl(aryl)(tetrafluoroborato)-lambda3-bromanes: 1-(phenylsulfonyl)- and 1-(trifluoromethylsulfonyl)cyclopentene annulation

Exposure of 1-alkynyl[p-(trifluoromethyl)phenyl](tetrafluoroborato)-lambda(3)-bromanes to sodium benzenesulfinate or sodium trifluoromethanesulfinate in dichloromethane at 0 degree C under argon resulted in tandem Michael-carbene insertion reactions to produce 1-sulfonylcyclopentenes selectively, with concomitant formation of a small amount of rearranged 1-alkynyl sulfones.     

Efficient preparation of glycoclusters from silsesquioxanes

[structure: see text] A new type of glycocluster based on polyhedral oligosilsesquioxanes (POSS) has been efficiently prepared from unprotected mannoside and lactoside employing a convergent approach of thiol-radical addition reaction. The versatility of this approach was demonstrated by functionalization of mannosides and lactosides of different-length spacers.