NIR analysis for batch process of ethanol precipitation coupled with a new calibration model updating strategy

Ethanol precipitation plays a major role in the pretreatment of Flos Lonicerae Japonicae of Qingkailing injection, and is also one of the most popular purification techniques in Chinese herbal medicines. In order to monitor and have a better understanding of the ethanol precipitation process, a PLS model was built based on NIR spectroscopy and HPLC analysis of chlorogenic acid content within the framework of FDA's PAT initiative. Nevertheless, due to the complex mechanism of and the raw materials’ natural variability introduced into the ethanol precipitation process, it was unable to foresee the variations in new batches which may jeopardize the robustness of the established model. Therefore, based on the simple interval calculation (SIC) theory, a new model expansion updating strategy which could continuously expand the variation coverage of the calibration model along with the batch proceeding of ethanol precipitation process was proposed. Effects of model updating were validated by an individual batch with 60 samples. After two times of updating, the root mean squared error of prediction (RMSEP) decreased from 0.268 mg mL⁻¹ to 0.199 mg mL⁻¹, while the insiders in the object status plot (OSP) increased from 44 to 58, demonstrating the good performance of the proposed approach.     

Bifunctional aluminum porphyrin complex: Soil tolerant catalyst for copolymerization of 2 and propylene oxide

Due to the concern on residue toxic metal in biodegradable poly(propylene carbonate) (PPC), soil tolerant and heavy metal free aluminum complexes, that is, bifunctional aluminum porphyrin catalysts bearing quaternary ammonium salts on the ligand framework were prepared. Variation of the quaternary ammonium anion and the axial ligand had dramatic effects on the catalytic activity of resultant complex, among which complex 3b yielded perfectly alternative PPC with high molecular weight and relatively narrow polydispersity, and its TOF reached 3,407 h^?1 at [PO]/[cat.] ratio of 20,000 at 110 °C, although the PPC selectivity was 71%. By introducing specific substituent on the ligand framework, the electronic environment at the active center can be changed, among which complex 5b bearing tertiary butyl‐functionalized aryl substituents exhibited a TOF of 449 h^?1 at [PO]/[cat.] ratio of 5,000 at 70 °C, with PPC selectivity of 92% and number average molecular weight of 36 kg mol^?1. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2346–2355     

Half‐sandwich ruthenium‐based versatile catalyst for both alcohol oxidation and catalytic hydrogenation of carbonyl compounds in aqueous media

A series of half‐sandwich ruthenium‐based catalysts for both alcohol oxidation and carbonyl compounds hydrogenation have been synthesized through metal‐induced C–H bond activation based on benzothiazole ligands. The neutral ruthenium complexes 1 – 4 were fully characterized by UV–vis, NMR, IR, and elemental analysis. Molecular structures of complexes 1 and 3 were further confirmed by X‐ray diffraction analysis. All complexes exhibited high activity for the catalytic oxidation of a variety of alcohols with ^tBuOOH as oxidants to give carbonyl compounds with high yields in water. Moreover, these half‐sandwich complexes also showed high efficiency for the catalytic hydrogenation of carbonyl compounds in a methanol–water mixture. The catalyst could be reused for at least five cycles without any loss of activity. The catalytic system also worked well for various kinds of substrates with either electron‐donating or electron‐withdrawing groups.     

2,3,4,5‐Tetraphenylsilole‐Based Conjugated Polymers: Synthesis,Optical Properties,and as Sensors for Explosive Compounds

A series of linear 2,5‐tetraphenylsilole‐vinylene‐type polymers were successfully synthesized for the first time. The tetraphenylsilole moieties were linked at their 2,5‐positions through a vinylene bridge with p‐dialkoxybenzenes to obtain polymer PSVB and with 3,6‐carbazole to obtain polymer PSVC . For comparison, 2,5‐tetraphenylsilole‐ethyne‐type polymer PSEB was also synthesized, in which the vinylene bridge of PSVB was replaced with an ethyne bridge. Very interestingly, the bridging group (vinylene or ethyne) had a significant effect on the photophysical properties of the corresponding polymers. The fluorescence peak of PSEB at 504 nm in solution originated from the emission of its silole moieties, whereas PSVB and PSVC emitted yellow light and no blueish–green emission from the silole moieties was observed, thus demonstrating that the emissions of PSVB and PSVC were due to their polymer backbones. More importantly, the 2,5‐tetraphenylsilole‐ethyne polymer exhibited a pronounced aggregation‐enhanced emission (AEE) effect but the 2,5‐tetraphenylsilole‐vinylene polymer was AEE‐inactive. Moreover, both AEE‐active 2,5‐tetraphenylsilole‐ethyne polymer and AEE‐inactive 2,5‐tetraphenylsilole‐vinylene polymers were successfully applied as fluorescent chemosensors for the detection of explosive compounds.     

Suzuki cross‐coupling reactions of aryl chlorides using [Cl2Pd(COD)]/piperazine derivative under microwave conditions

A new strategy to significantly improve the efficiency of Suzuki reactions was achieved under microwave irradiation. [Cl₂Pd(COD)]/piperazine derivative 1 catalyzed aryl chlorides with phenylboronic acid in methanol (50%) affording excellent yields under aerobic conditions. Application of this strategy to the synthesis of liquid crystal material is also described. Copyright © 2011 John Wiley & Sons, Ltd.     

A highly efficient cobalt-catalyzed deuterogenolysis of diboron: Synthesis of deuterated pinacolborane and vinylboronates

Highly efficient hydrogenolysis and deuterogenolysis of diboron compounds have been realized by the use of a cobalt catalyst, affording TON up to 48201. Furthermore, a one-pot two-step procedure comprising sequential deuterogenolysis of diboron and deuteroboration of alkynes under the same cobalt catalyst has been developed for the efficient, atom-economical synthesis of deuterated vinylboronates with high deuterium incorporation and excellent regio- and stereoselectivity.     

高效液相色谱-串联质谱法测定酵素食品中的匹可硫酸钠

建立了高效液相色谱-串联质谱法测定酵素食品中新型减肥类非法添加物匹可硫酸钠的分析方法。针对现有方法不适用的果冻、软糖型样品，开发了新的前处理方法。样品经水提取、聚酰胺净化，使用Thermo Accucore RP-MS色谱柱（100 mm×2.1 mm，2.6 μm），以乙腈-10 mmol/L乙酸铵（15：85，v/v）等度洗脱，流速0.3 mL/min，柱温35℃，多反应监测（MRM）模式下质谱检测，外标法定量。结果表明，匹可硫酸钠在5~500 μg/L范围内线性关系良好，相关系数（r）为0.9999，方法检出限为0.05 mg/kg。匹可硫酸钠在各基质样品中的加标回收率为89.2%~111.8%，相对标准偏差为2.5%~10.4%。按上述方法检测152批次酵素食品，检出阳性样品58批次，检出率为38.2%。该法准确、灵敏，可用于酵素食品中匹可硫酸钠的测定。     

Synthesis of tertiary carbinamines

An efficient synthesis of tertiary carbinamines using a one-pot, three-component reaction employing TMSCl activation of an intermediate imine salt followed by addition of an organometallic is described. An optimized second generation chiral synthesis of select tertiary carbinamines utilizing the Ellman sulfinamine was subsequently developed on a multi-gram scale and is also described.