NMR位移试剂Eu(fod)~4^-对锍盐^1H和^1^3C NMR的影响

合成了八种新的四氟硼酸二甲基苯基锍，用元素分析和核磁共振对其结构进行了表征。研究了以CDCl~3为溶剂，NMR位移试剂Eu(fod)~4^-对所合成锍盐的^1H和^1^3C NMR的影响。结果表明，Eu(fod)~4^-是一个对锍盐非常有效的位移试剂，且Eu(fod)~4^-对二甲基苯基锍盐之甲基的^1H和^1^3C NMR的位移呈线性关系。     

离子液体载催化剂和载试剂在有机合成中的应用

综述了离子液体载催化剂和载试剂在有机合成中的应用进展. 离子液体载催化剂是针对离子液体中催化剂难以回收利用的问题提出来的, 它不仅可以实现均相催化, 而且反应产物容易分离, 催化剂可以循环使用. 离子液体载有机试剂合成, 又称为离子液体相有机合成, 具有固相反应产物纯度高和液相反应反应快的优点. 在离子液体载无机试剂的反应中, 反应物毒性降低, 反应条件温和, 产物选择性好.     

Reaction of Alkanesulfinyl Chloride with Grignard Reagents： a Convenient Synthesis of Alkyl Sulfoxides

Alkyl sulfoxides were synthesized in good yields from the reaction of alkanesulfinyl chloride with Grignard reagents in the presence of zinc chloride.     

Reaction of Grignard Reagents with Diethyl Perfluoroacyl (1-Cyanoethyl)phosphonates. Synthesis of Perfluoroalkylated α,β-Unsaturated Nitriles with Predominant Z-Selectivity

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Microwave-promoted one-pot synthesis of 4H-thiopyrans from α,β-unsaturated ketones via a three-component reaction

An efficient one-pot synthesis of substituted 4H-thiopyrans has been accomplished from a three-component reaction of α,β-unsaturated ketones, Lawesson’s reagent and alkynes under microwave irradiation.     

Synthesis and Crystal Structure of 1，5－Bis（1＇－phenyl－3＇－methyl－5＇－pyrazolone－4＇）－1－（4＇－aminobutand－1＇－imino）－5－pentaneone

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆ１，５－Ｂｉｓ（１＇－ｐｈｅｎｙｌ－３＇－ｍｅｔｈｙｌ－５＇－ｐｙｒａｚｏｌｏｎｅ－４＇）－１－（４＇－ａｍｉｎｏｂｕｔａｎｄ－１＇－ｉｍｉｎｏ）－５－ｐｅｎｔａｎｅｏｎｅ￥ＹａｎｇＬｕ－Ｑ...     

Validated Enantioselective LC Method, with Precolumn Derivatization with Marfey’s Reagent, for Analysis of the Antiepileptic Drug Pregabalin in Bulk Drug Samples

An enantioselective high-performance liquid chromatographic method, with precolumn derivatization with Marfey’s chiral reagent, sodium 2,4-dinitro-5-fluorophenyl-l-alanine amide, has been developed for resolution of the enantiomers of a new antiepileptic drug, pregabalin, in the bulk drug. The diastereomers of the pregabalin enantiomers were resolved to baseline on a reversed-phase ODS column with a 60:40 (v/v) mixture of aqueous 0.2% triethylamine (pH adjusted to 3.5 with dilute orthophosphoric acid) and acetonitrile as mobile phase. Resolution between the diastereomers was not less than five. The method was extensively validated and proved to be robust. The calibration plot was indicative of an excellent linear relationship between response and concentration over the range 750 (LOQ) to 7,500 ng L⁻¹ for the R enantiomer. The limits of detection and quantification of the R enantiomer were 250 and 750 ng L⁻¹, respectively, for an injection volume of 10 μL. Recovery of the R enantiomer from bulk drug samples of pregabalin ranged from 97.5 to 101.76%. Solutions of pregabalin in water and in the mobile phase were found to be stable for at least 48 h. The method was found to be suitable and accurate for quantitative determination of the R enantiomer in the bulk drug. It can be also used to test the stability of samples of pregabalin.     

Chemical analysis for small amounts of horseradish peroxidase using “porphyrinogen” as a chromogenic reagent

The properties of porphyrinogen as a new chromogenic reagent were examined. 5,10,15,20-Tetrahydro-tetraphenylporphyrinogen (TPPN) is changed to 5,10,15,20-tetraphenylporphine (TPP) by the oxidative reaction involving six electrons, and its formation of the porphine ring significantly increased the absorbance in the Soret band.The horseradish peroxidase (HRP) accelerated the oxidative reaction as a catalyst and the increment of absorbance depended upon the increase in the concentration of HRP. The reaction proceeded in the presence of dissolved oxygen and in the neighborhood of pH 7. Based on these findings, a chemical analysis by catalytic action using HRP was developed.In the procedure for this determination, the difference in absorbance at 419 nm (ΔA₄₁₉=A_s−A_b, where A_s and A_b are the absorbances of the sample solution containing HRP and the blank solution without HRP after 30 min, respectively), was measured. The determination range of HRP, which was obtained from the ΔA₄₁₉—HRP concentration curve, was 0.05-1.0 mg/l. The relative standard deviation in the median of the calibration curve was 3.19% (seven determinations), and the detection limit (S/N=3) was 29 ng/l. Furthermore, when the proposed method was applied to the enzyme immunoassay, bisphenol A (BPA) was selectively and sensitivity determined.     

Synthesis of new diheteroarylcarbazoles: a facile and simple route of 3,6-di(pyrazol-4-yl)carbazoles

A short and facile route to the synthesis of new 3,6-di(pyrazol-4-yl)carbazoles is reported. Dipyrazolylcarbazoles were synthesized in two steps from 3,6-diacetylcarbazoles through a Vilsmeier reaction which led to the formation of carbazolyl-β-chlorovinyl aldehydes, followed by cyclization with hydrazine hydrate. The reaction of the Vilsmeier reagent with hydrazones of diacetylcarbazoles yielded the corresponding pyrazole dicarbaldehydes in good yields.     

低价钛引起的芳酮肟的反应

在低价钛试剂 (TiCl4/Sm)作用下取代苯乙酮肟发生脱肟反应生成酮 ,而在同样条件下 ,二芳酮肟则生成二芳酮、胺或希夫碱