一种新型手性席夫碱的合成及其在不对称环丙烷化反应中的催化性能

在不对称催化的发展过程中,设计与合成新的手性配体一直是人们所关注的热点,并已取得很大的进展[1].     

Rapid quantification of levosulpiride in human plasma using RP‐HPLC‐MS/MS for pharmacokinetic and bioequivalence study

A rapid and validated method for analysis of levosulpiride in human plasma using liquid chromatography coupled to tandem mass spectrometry was developed. Levosulpiride and tiapride (IS, internal standard) were extracted from alkalized plasma samples with ethylacetate and separation by RP‐HPLC. Detection was performed by positive ion electrospray ionization in multiple‐reaction monitoring mode, monitoring the transitions m/z 342.1 → m/z 112.2 and m/z 329.1 → m/z 213.2, for quantification of levosulpiride and IS, respectively. The standard calibration curves showed good linearity within the range of 2–200 ng/mL (r² ≥ 0.9990). The lower limit of quantitation was 2 ng/mL. The retention times of levosulpiride (0.63 min) and IS (0.66 min) presented a significant time saving benefit of the proposed method. No significant metabolic compounds were found to interfere with the analysis. This method offered good precision and accuracy and was successfully applied for the pharmacokinetic and bioequivalence study of a 25 mg of levosulpiride tablet in 24 healthy Korean volunteers. Copyright © 2009 John Wiley & Sons, Ltd.     

Catalytic autooxidation ofp-anisaldehyde and styrene by a cobaltbis-schiff base complex

Summary The Co^II complex derived from the unsymmetricalbis-Schiff base ligand, 3-[1-[[2-[[(2-hydroxyphenyl)methylene]-amino]ethyl]amino]ethylidene]-6-methyl-2H-pyran-2,4(3H) dione H₂(dha, salen), is a catalyst for the autoxidation of aromatic aldehydes. Under ambient condition Co(dha, salen) catalyses the oxidation ofp-anisaldehyde top-anisic acid in quantitative yield (250 turnovers). The presence of Co(dha, salen) also accelerates the co-oxidation ofp-anisaldehyde and styrene (88 turnovers). In the co-oxidation process, styrene is selectively converted to styrene oxide as the major product.     

Highly efficient, reversible addition of activated methylene compounds to styrene derivatives catalyzed by silver catalysts

[reaction: see text] A highly efficient inter- and intramolecular addition of 1,3-diketone/beta-ketoester to alkenes was developed by using silver catalysts. Silver triflate shows the highest catalytic activity. The reaction is reversible through the cleavage of a carbon-carbon bond by silver at an elevated temperature.     

The Permutation Modules for GL(n+1, Fq) Acting on Pn(Fq) and Formula

The paper studies the permutation representations of a finitegeneral linear group, first on finite projective space and thenon the set of vectors of its standard module. In both casesthe submodule lattices of the permutation modules are determined.In the case of projective space, the result leads to the solutionof certain incidence problems in finite projective geometry,generalizing the rank formula of Hamada. In the other case,the results yield as a corollary the submodule structure ofcertain symmetric powers of the standard module for the finitegeneral linear group, from which one obtains the submodule structureof all symmetric powers of the standard module of the ambientalgebraic group.     

Approximate solution of boundary layer problems with injection or suction

Zusammenfassung Der grundlegende linearisierte Ansatz zur Näherungslösung von Grenzschichtproblemen wird auf neue Anwendungen erweitert, um die Behandlung von Problemen mit Massenaustausch durch die Oberfläche zu ermöglichen und die Beschränkung auf die Prandtl-Zahl 1 zu mildern. Das klassische Problem der konstanten, d. h. nicht ähnlichen Geschwindigkeitsverteilung an der Oberfläche wird behandelt, und die Ergebnisse werden mit der exakten numerischen Lösung verglichen. Es ergibt sich eine ausgezeichnete Übereinstimmung. Sodann wird eine Lösung des schwierigen und praktisch wichtigen Problems einer Stufenfunktion für die Oberflächengeschwindigkeit gegeben. Die freie Konvektion über einer vertikalen Platte mit konstanter Temperatur und Oberflächengeschwindigkeit wird erstmalig gelöst. Schliesslich wird das der Schlitzeinspritzung entsprechende Anfangswertproblem unter Milderung der bisherigen AnnahmeP _r =1 behandelt.

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This work was supported by the National Science Foundation, Grant No. GK-310,     

氟对别洛索夫-扎鲍京斯基振荡反应的影响

报道了氟离子对Ce(SO4) 2 KBrO3 CH2 (COOH) 2 H2 SO4(B Z)振荡体系的干扰 ,考察了在 5× 10 - 5～ 1× 10 - 3 mol L范围内 ,F- 的浓度与振荡反应周期的改变ΔTP 之间的关系。结合FKN机理模型 ,提出了F- 干扰振荡反应的机理 ,为其应用奠定基础     

烯烃不对称催化环丙烷化反应进展评述

本文从手性配体的发展出发, 综述了烯烃不对称环丙烷化反应近10 年来的研究进展, 对半咕啉、双　唑啉等C₂ 轴手性配体在该反应中的应用做了详细论述, 介绍了反应机理研究的最新进展, 并探讨了该反应在走向工业应用过程中所面临的主要问题。