Direct beta-alkylation of secondary alcohols with primary alcohols catalyzed by a CpIr complex

A new catalytic system for beta-alkylation of secondary alcohols has been developed. In the presence of [CpIrCl(2)](2) (Cp = pentamethylcyclopentadienyl) catalyst and base, the reactions of various secondary alcohols with primary alcohols give beta-alkylated higher alcohols in good to excellent yields without any hydrogen acceptor or hydrogen donor. This reaction proceeds via successive hydrogen-transfer reactions and aldol condensation. [reaction: see text]     

Pd-catalyzed asymmetric allylic alkylation with nitromethane using a chiral diaminophosphine oxide: (S,RP)-Ph-DIAPHOX. Enantioselective synthesis of (R)-preclamol and (R)-baclofen

A Pd-catalyzed asymmetric allylic alkylation with nitromethane using an aspartic acid-derived P-chirogenic diaminophosphine oxide [(S,R_P)-Ph-DIAPHOX] is described. This method was successfully applied to enantioselective synthesis of (R)-preclamol and (R)-baclofen.     

Characterization of Cu species on SiO2 and ZSM-5 by temperature-programmed reduction by ammonia

We studied the temperature-programmed reduction by NH₃ (NH₃-TPR) as a supplement to the temperature-programmed reduction by H₂ (H₂-TPR) for the characterization of supported Cu species. The NH₃-TPR profile of Cu/SiO₂, which contained only bulk CuO, exhibited two peaks for N₂ formation in equal amounts, suggesting stepwise reduction of the bulk CuO. In contrast, the H₂-TPR profile exhibited only one H₂ consumption peak. We also studied Cu-NaZSM-5 samples with various Cu and Na loadings. The Cu ions on ZSM-5 were reduced to Cu⁺ but no further. Kinetic analysis revealed that the NH₃-TPR profile exhibited peaks for separate reductions of isolated and binuclear Cu²⁺ ions. Thus, we found NH₃-TPR to be useful for detailed analysis of the reducibility of Cu²⁺ to Cu⁺ in zeolite pores.     

Catalytic asymmetric epoxidation of α,β-unsaturated carboxylic acid imidazolides and amides by lanthanide–BINOL complexes

Highly enantioselective catalytic asymmetric epoxidation of α,β-unsaturated carboxylic acid imidazolides and simple amides was developed. In the presence of 5–10 mol% of lanthanide–BINOL complexes, the reaction proceeded smoothly with high substrate generality. In particular, in the cases of α,β-unsaturated amides, there was nearly perfect enantioselectivity (>99% ee). The corresponding epoxides were successfully transformed into many types of useful chiral compounds such as α,β-epoxy esters, α,β-epoxy amides, α,β-epoxy aldehydes, α,β-epoxy β-keto ester, and α- and β-hydroxy carbonyl compounds. B3LYP density functional studies were performed to predict substrate reactivity.     

Confocal calcium imaging with ultraviolet laser- scanning microscopy and indo-1

We developed a newly designed ultraviolet laser-scanning confocal microscopy (UV-LSCM) system and applied it for quantitative confocal imaging of intracellular calcium concentration ([Ca²⁺]_i) with the dual-emission wavelength indicator indo-1. The resolution and contrast of the biological sample images obtained using the current UV system were found to be comparable to those obtained with the conventional visible LSM optics and hence the UV-transmittable optics in our LSM system employing an achromatic objective lens provides appreciable confocality in the UV range. When indo-1 is used with this UV-LSCM system, dual- imaging ratiometric measurement of [Ca²⁺]_i can be easily performed without requiring time-consuming geometrical decalibration of the two simultaneously obtained images. The resulting confocal images allow quantitative analysis of [Ca²⁺]_i in rapidly contractile cardiac cells at a high temporal resolution in line-scan and fast frame-scan modes. The combined use of the UV-LSCM and dual- emission ratiometric indicator is now practical and we anticipate its widespread application in physiological and pathological studies in living cells.     

Synchrotron radiation studies of the orientation of thin silicon phthalocyanine dichloride film on HOPG substrate

Thin silicon Phthalocyanine dichloride films on HOPG were prepared and the sample was heated in the vacuum with laser.The thickness of the thin sample on HOPG was checked by X-ray photoemission spectroscopy.The orientation of the molecules in respect to the substrate plane Was investigated by measuring the silicon K-edge near edge X-ray absorption fine structure(NEXAFS).In the NEXAFS spectra of the thin sample,two clear peaks which were assigned to 1s→σ*Si-N and 1s→σ*Si-C1 appeared around 1847.2 eV and 1843.1 eV respectively.The intensities of the resonance peaks showed strong polarization dependence.A quantitative analysis of the polarization dependence revealed that the Si-N bond tended to lie down while the Si-C1 bond was out of the molecular plane.     

Study on selective adsorption of deuterium on boron nitride using photon-stimulated ion-desorption

Adsorption behavior of atomic deuterium on a hexagonal boron nitride (h-BN) thin film is studied by photon-stimulated ion desorption (PSID) of D⁺ and near edge X-ray absorption fine structure (NEXAFS) at the B and N K-edges. After the adsorption of atomic deuterium, D⁺ desorption yield η(hν) shows clear enhancement at the B K-edge and almost no enhancement at the N K-edge. NEXAFS spectra show a large change in the B K-edge and a small change in the N K-edge after the adsorption. We propose selective adsorption of atomic deuterium on the h-BN thin film based on the experimental results, and mention the effectiveness of applying the PSID method with X-ray to study hydrogen storage materials.     

Synthesis and adsorptivity of acryloylmorpholine resin to various fission product elements in nitric acid media

A novel silica-supported resin with a cyclic monoamide of polymerized 4-acryloylmorpholine(Silica-AM) was synthesized, and adsorptivity to metal ions of major fission products(FP) was examined in HNO3 and HCl solutions. Silica-AM has a carbonyl oxygen atom outside of the 6-membered morpholine ring, and a cyclic structure that is different than other cyclic monoamide resins we have studied. These include polyvinylpolypyrrolidone(PVPP) and poly-N-vinyl-ε-caprolactam(VEC), both of which have coordinative carbonyl groups included in the ring. Silica-AM was similar to a cyclic monoamide we have reported because it exhibited adsorption to Pd(Ⅱ) and Re(VⅡ) in HNO3 of a particularly low concentration range. Silica-AM has an ether oxygen atom included in the ring as well. Considering the difference in the chemical structures of Silica-AM and other cyclic monoamide resins, it was suggested that oxygen atoms in the carbonyl group and in ether may be main contributors to Silica-AM's respective adsorptions to Pd(Ⅱ) and Re(VⅡ), and Mo(VI) and Zr(IV). Our results imply that the contribution of the two types of oxygen atoms to adsorption is more observable in an HCl system. The contribution of the ether oxygen atom to the adsorption of Pd(Ⅱ) was also suggested from our study on crystal prepared from 4-acetylmorpholine and palladium nitrate.