Preparation of N'-[2-(5,6-dimethylbenzothiazolyl)]-N-furfuryloxamide with plant growth regulatory activity

The reaction of the N-furfuryloxamic acid sodium salt (12) with 1,1'-oxalyldiimidazole (ODI) yielded the imidazolide (13) as an intermediate, and this directly reacted with 2-aminothiazole derivatives (14) or 2-aminobenzothiazole derivatives (15) under essentially neutral conditions to afford the N'-12-(substituted thiazolyl)]- or N'-[2-(substituted benzothiazolyl)]-N'-furfuryloxamides (6 or 7). The prepared compounds (6 and 7) were examined for plant growth regulatory activity in a seed germination assay. The examination resulted in the discovery of some new revelations that N'-[2-(5,6-dimethylbenzothiazlyl)]-N-furfuryloxamide (7c) at the concentration of 1.0 x 10(-3) M completely inhibited the radicle growth of both rape and leek seedlings.     

Characterization of polypropylenes prepared with bis‐indenyl type metallocene and MgCl2‐supported TiCl4 catalyst systems

The homo‐polypropylene: m‐PP, prepared with rac‐Me₂Si[2‐n‐Pr‐4‐(9‐Phenanthryl)‐Ind]₂ZrCl₂, showed 99.6% of [mmmm] and 162.8°C of melting temperature (Tm). This polymer was compared by TREF analysis with the homo‐polypropylene: Ti‐PP, which was produced by our latest MgCl₂‐supported TiCl₄ catalyst system and showed 99.0% of [mmmm] and 165.7°C of Tm. It was indicated that m‐PP has narrower stereoregurality distribution than Ti‐PP and Tm of the fraction eluted from m‐PP at the highest temperature range is 163.6°C, while that from Ti‐PP reaches to 167.3°C. The characters and advantages of each polymer are discussed on the basis of these results. In addition, an advantage of this metallocene was made clear by characterization of polypropylenes copolymerized with ethylene.     

七甲茚基稀土络合物和碱金属盐的化学反应

本文用核磁共振等方法研究了稀土络合物和碱金属盐中的七甲茚基的质子化或氘化反应、亲核取代反应及络合物中稀土离子的还原反应。七甲茚基络合物比相应的茂基或茚基化合物更易与盐进行上述反应。三氘代七甲茚基在氘化反应中显示了同位素效应。     

Depth profiling in secondary ion mass spectrometry for ultra‐thin layer with nanometer order thickness by mesa‐structure fabrication

We attempted to make an accurate depth profiling in secondary ion mass spectrometry (SIMS) including backside SIMS for ultra‐thin nanometer order layer. The depth profiles for HfO₂ layers that were 3 and 5 nm thick in a‐Si/HfO₂/Si were measured using quadrupole and magnetic sector type SIMS instruments. The depth profiling for an ultra‐thin layer with a high depth resolution strongly depends on how the crater‐edge and knock‐on effects can be properly reduced. Therefore, it is important to control the analyzing conditions, such as the primary ion energy, the beam focusing size, the incidence angle, the rastered area, and detected area to reduce these effects. The crater‐edge effect was significantly reduced by fabricating the sample into a mesa‐shaped structure using a photolithography technique. The knock‐on effect will be serious when the depth of the layer of interest from the surface is located within the depth of the ion mixing region due to the penetration of the primary ions. Finally, we were able to separately assign the origin of the distortion to the crater‐edge effect and knock‐on effect. Copyright © 2012 John Wiley & Sons, Ltd.     

Effect of Cation Arrangement on the Magnetic Properties of Lithium Ferrites (LiFeO2) Prepared by Hydrothermal Reaction and Post-annealing Method

The magnetic properties of several LiFeO₂polymorphs (different cation arrangements in a cubic close-packed oxygen structure) have been examined by magnetic susceptibility measurements and Mössbauer spectroscopy. Samples with relatively low ferromagnetic impurity levels have been obtained by hydrothermal reaction of FeCl₃·6H₂O or FeOOH with LiOH·H₂O and subsequent annealing in air.α-NaFeO₂with no detectable ferromagnetic impurity has been obtained by hydrothermal reaction ofα-FeOOH and NaOH. Whileα-NaFeO₂revealed only one anomaly at 11 K (Néel point) in the magnetic susceptibility–temperature curves, each LiFeO₂sample shows two anomalies (40–50 and 90–280 K). Mössbauer data confirm that iron is present in the high-spin 3+ state according to the values of the internal field at 4.2 K and isomer shifts at 300 K. The relationship between the cation arrangements and the Néel temperature is discussed for LiFeO₂.     

Relative quantification of enantiomers of chiral amines by high-throughput LC–ESI-MS/MS using isotopic variants of light and heavy l-pyroglutamic acids as the derivatization reagents

l-Pyroglutamic acid (l-PGA) was evaluated as a chiral labeling reagent for the enantioseparation of chiral amines in terms of separation efficiency by reversed-phase chromatography and detection sensitivity by ESI-MS/MS. Several amines and amino acid methyl esters were used as typical representatives of the chiral amines. Both enantiomers of the chiral amines were easily labeled with l-PGAs at room temperature for 60 min in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1-hydroxy-1H-benzotriazole as the activation reagents. The resulting diastereomers were completely separated by reversed-phase chromatography using the small particle (1.7 μm) ODS column (Rs = 1.6–6.8). A highly sensitive detection at a low-fmol level (1–4 fmol) was also obtained from the multiple reaction monitoring (MRM) chromatograms. Therefore, a high-throughput determination was achieved by the present UPLC–ESI-MS/MS method.     

Dinitrogen‐Molybdenum Complex Induces Dinitrogen Cleavage by One‐Electron Oxidation

Reported here is the N₂ cleavage of a one‐electron oxidation reaction using trans‐[Mo(depe)₂(N₂)₂] ( 1 ) (depe=Et₂PCH₂CH₂PEt₂), which is a classical molybdenum(0)‐dinitrogen complex supported by two bidentate phosphine ligands. The molybdenum(IV) terminal nitride complex [Mo(depe)₂N][BArf₄] ( 2 ) (BArf₄=B(3,5‐(CF₃)₂C₆H₃)₄) is synthesized by the one‐electron oxidation of 1 upon addition of a mild oxidant, [Cp₂Fe][BArf₄] (Cp=C₅H₅), and proceeds by N₂ cleavage from a Mo^II‐N=N‐Mo^II structure. In addition, the electrochemical oxidation reaction for 1 also cleaved the N₂ ligand to give 2 . The dimeric Mo complex with a bridging N₂ is detected by in situ resonance Raman and in situ UV‐vis spectroscopies during the electrochemical oxidation reaction for 1 . Density‐functional theory (DFT) calculations reveal that the unstable monomeric oxidized Mo^I species is converted into 2 via the dimeric structure involving a zigzag transition state.     

Stereoselective total synthesis of acremomannolipin A and its anomer,the potent calcium signal modulators with a novel glycolipid structure: role of the stereochemistry at the anomeric center on the activity

A full account of stereoselective total synthesis of a novel glycolipid, acremomannolipin A (1), the potent calcium signal modulator isolated from Acremonium strictum, by employing the stereoselective β-mannosylation of 4,6-O-benzylidene-protected mannosyl sulfoxide with d-mannitol as the key reaction is described. The α-anomer (epi-1) of 1 was also synthesized selectively. The calcium modulating activity was reduced upon inversion of the configuration at the anomeric center, indicating that the β-configuration of the mannose moiety is preferable for the activity.