Visible-light-mediated selective thiocyanation/ipso-cyclization/oxidation cascade for the synthesis of thiocyanato-containing azaspirotrienediones

A visible-light-mediated metal-free thiocyanate radical addition/ipso-cyclization/oxidation cascade reaction for the synthesis of thiocyanato-containing azaspirotrienediones from N-phenylpropynamides is described. Cheap and readily available ammonium thiocyanate was used as a precursor to the thiocyanate free radical, which undergoes a radical addition reaction with the alkyne, followed by selective ipso-cyclization and oxidation to afford the dearomatized products. No product of ortho-cyclization was detected. The reaction completes the synthesis of C–S, C–C, and CO bonds in one pot, with abundant and renewable air oxygen as the sole sacrificial reagent and oxygen source.     

Regioselective protection of xylose for efficient synthesis of arabino-α-1,3-xylosides

We reported here an efficient regioselective protection strategy for xylose with two-step successive protections on 4- and 2-OH. This method enables the expeditious preparation of various xylose building blocks (3a–c, 5, 6). The rapid selective 2,4-protection especially facilitates the synthesis of 3-substituted xyloside structures. By this approach, typical arabino-α-1,3-xyloside disaccharide and trisaccharide, as fragment structure units from arabinoxylans, have been successfully synthesized.     

LiNi0.8Co0.15Al0.05O2正极材料的FePO4包覆改性

使用液相包覆工艺对LiNi_(0.8)Co_(0.15)Al_(0.05)O_2(NCA)材料进行FePO_4包覆改性,利用FePO_4优异的结构稳定性与热稳定性,对NCA的长期可靠性与安全性能进行改良。重点研究FePO_4包覆对NCA材料的改性效果,以及不同包覆量造成的NCA材料电化学性能差异。表面包覆的FePO_4保护层,能够防止NCA材料与电解液直接接触发生副反应,抑制长期循环过程中过渡金属离子的溶出,保持结构的长期稳定性。当包覆量为1.0%(w/w)时,NCA材料表现出最优的综合性能,充放电循环800次后,容量保持率依然高达95%,25℃下存储100 d后,容量保持率也高于95%,达到了兼顾能量密度、使用寿命及安全性能的理想效果。     

Newton’s Method for M-Tensor Equations

Journal of Optimization Theory and Applications - We are concerned with the tensor equations whose coefficient tensors are M-tensors. We first propose a Newton method for solving the equation with...     

A new rapid ultra‐performance liquid chromatography method for the pharmacokinetic and bioavailability study of diclofenac sodium aqueous injection and lipid microsphere injection in rats

A novel, rapid and selective ultra performance liquid chromatography mass spectrometric method had been developed for the pharmacokinetic study of diclofenac sodium (DS) after single intravenous injection of DS aqueous injection and DS lipid microsphere (LM) injection in rats. Ketoprofen (KP) was used as internal standard. Samples were treated by a one‐step liquid liquid extraction. Separation was performed on an Acquity UPLC? BEH C₁₈ column (50 × 2.1 mm i.d., 1.7 μm). The mobile phase consisted of acetonitrile–0.1% ammonium hydroxide aqueous solution (20 : 80, v/v) initially in the gradient mode. The detection was carried out by means of electrospray ionization mass spectrometry in negative ion mode with multiple‐reaction monitoring mode. Standard curves showed good linearity (r > 0.99) from the plasma concentration of 0.1–50 μg/mL. The lower limit of quantification was 0.1 μg/mL. The intra‐ and inter‐day precisions and the accuracy all satisfied the acceptance criteria. The developed method was validated and successfully applied to the pharmacokinetics study of DS aqueous injection and LM injection. The results showed that the two preparations were bioequivalent in rats. Copyright © 2009 John Wiley & Sons, Ltd.