Second-order nonlinear optical properties from poled silicate channel-waveguide

Thin film waveguides of germanosilicate glass are fabricated byrf-sputtering. Second-order nonlinearity ofd ₃₃=3.2 pm/V is obtained from electrically poled film, and the lifetime of the nonlinearity is found to be310 years. The poled channel-waveguide is prepared and the Cerenkov-type phase-matched frequency doubling is successfully observed.     

Nitrosation of Phenolic Substrates under Mildly Basic Conditions: Selective Preparation of p-Quinone Monooximes and Their Antiviral Activities

Nitrosation of 3-methoxyphenol and 1-naphthol were examined under both acidic (NaNO(2)-EtCO(2)H-H(2)O) and basic (i-AmNO(2)-K(2)CO(3)-DMF) conditions. Acidic nitrosations afforded ortho-directed products, whereas para-directed nitrosations were observed under basic conditions to yield p-quinone monooximes. The basic para-directed nitrosation was further examined using 15 phenols, two naphthols, and four phenolic heterocyclics. A one-pot operation of the basic nitrosation followed by methylation with dimethyl sulfate gave the corresponding methyl ethers in high yield. Two p-quinone monooximes derived from 3-methoxyphenol and 8-hydroxyquinoline showed a moderate activity against HSV-1, and the latter oxime was also effective against HSV-2. On the other hand, p-quinone monooximes derived from methyl salicylate, 1-naphthol, 7-hydroxy-2-methylbenzo[b]furan, and 8-hydroxycoumarin showed the comparable activity to that of DDI against HIV-1.     

Preparation and electrochemical polymerization of new multifunctional pyrrolethiolate-stabilized gold and palladium nanoparticles

New pyrrolylalkanethiolate-stabilized gold and palladium nanoparticles have been prepared: electrochemical polymerization of their metal nanoparticles and their TEMPO-derivatized metal nanoparticles gave the remarkably stable poly(pyrrole metal nanoparticle) films on metal electrodes.     

Facile routes to natural acyclic polyenes syntheses of spilanthol and trail pheromone for termite

The synthetic procedures for spilanthol and trail-following pheromone for a southern subterranean termite were described. The syntheses heavily depend on the new diene synthesis using titanium reagent.     

Enantioselective O- and N-nitroso aldol synthesis of tin enolates. Isolation of three BINAP-silver complexes and their role in regio- and enantioselectivity

The selective generation of three different silver-BINAP catalysts has been achieved via the proper combination of metal/ligand ratio and/or choice of silver salt. Indeed, the X-ray crystallographic study has been used to gain insight into the structure of the catalyst. After the evaluation of each species, 1:1 (AgX.(R)-BINAP) complex was found to be the real active species in the O-selective nitroso aldol reaction. On the other hand, a systematic survey of solvent has shown that the optimal 2:1 (AgX.(R)-BINAP) complex is the effective catalyst in the N-selective pathway. Thus, a new method of generation of the silver-BINAP catalyst and the synthetic transformations provide not only new insights into the developing area of catalytic enantioselective nitroso aldol synthesis but also clear guidance for the design of an effective catalyst.     

Stereoselective synthesis of 1,4-disubstituted 1,3-diene

New synthetic methods for the preparation of 1,3-dienes are described.     

Pseudoguaiane-type sesquiterpenes and inhibitors on nitric oxide production from Dichrocephala integrifolia

Three new pseudoguaiane-type sesquiterpenes, dichrocepholides A-C, and two new pseudoguaiane-type sesquiterpene dimers, dichrocepholides D and E, were isolated from the aerial part of Dichrocephala integrifolia. Their stereostructures were determined on the basis of chemical and physicochemical evidence. In addition, the extract and its principal sesquiterpene constituent, parthenin, showed an inhibitory activity on nitric oxide (NO) production and on induction of inducible NO synthase.