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121.
Zhifu Jiang Jian Zhao Beibei Gao Shuo Chen Wenyan Qu Xiangdong Mei 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1026-1037
Abstract A series of novel (4′-tosyl) piperidin-4-yl containing α-aminophosphonates were synthesized by a one-pot reaction, efficiently catalyzed by magnesium perchlorate, under solvent-free conditions from 1-tosylpiperidin-4-one, substituted aromatic amines, and diethyl phosphite (DEP). The synthesized compounds were characterized by IR, 1H NMR, 13C NMR, 31P NMR, and HRMS spectroscopy. A single-crystal X-ray structure of diethyl 4-(2-chlorophenyl) amino-1-(4’-methylbezenesulfonyl) piperidin-4-yl-phosphonate (2a) was obtained, and some of the title compounds displayed insecticidal activities against Plutella xylostella. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables. 相似文献
122.
Guang-Feng Hong Zhen-Hua Dong Yong-Mei Xiao Pu Mao Ling-Bo Qu 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):771-779
AbstractA practical metal-free procedure for the synthesis of (E)-vinyl sulfones has been developed through the coupling of β-nitrostyrenes with sodium sulfinates under microwave irradiation. This methodology provides a convenient and efficient approach to various (E)-vinyl sulfones from readily available starting materials with excellent regioselectivity. The present oxidative reaction involves an efficient denitrative radical cross-coupling of β-nitrostyrenes with sodium sulfinates via using AcOH as an additive. 相似文献
123.
Microwave-assisted tandem reaction of(Z)-arylvinyl bromides involving an elimination and homocoupling in the presence of DBU and Cul in DMF affords a variety of symmetrical 1,3-diynes in good to excellent yields.This tandem process,eliminating the need of volatile and savory terminal alkynes,provides an alternative to the conventional homocoupling methods for the synthesis of symmetrical 1,3-diynes. 相似文献
124.
Yanqin Qu Congcong Liu Feng Luo Bin Qiu Xi Chen 《Journal of separation science》2013,36(24):3889-3895
We developed a solid‐phase microextraction coupled to GC with electron‐capture detection method for the detection of acrylamide in food samples. Single‐walled carbon nanotubes and polypyrrole were electropolymerized onto a stainless‐steel wire as a coating, which possessed a homogeneous, porous, and wrinkled surface, chemical and mechanical stability, long lifespan (over 300 extractions), and good extraction efficiency for acrylamide. The linearity range between the signal intensity and the acrylamide concentration was found to be in the range 0.001–1 μg/mL, and the coefficient of determination was 0.9985. The LOD, defined as three times the baseline noise, was 0.26 ng/mL. The reproducibility for each single fiber (n = 6) and the fiber‐to‐fiber (n = 5) repeatability prepared in the same batch were less than 4.1 and 11.2%, respectively. 相似文献
125.
Jiamin Gu Reihong Feng Zhiyuan Wu Shuguang Guan Jiling Guo Chunru Cheng Pingping Xu Jingxian Zhang Yang Wang Hua Qu Wei Man Wenbo Yu Yajun Cui Shuhong Guan Dean Guo 《Journal of separation science》2013,36(14):2366-2372
A rapid and convenient method was established to preparatively isolate the three ellagic acid types of compounds, which were the main polyphenols in Euphorbia pekinensis, by flexibly applying solvent extraction combined with counter‐current chromatography (CCC). The total extract (extracted using 95% ethanol) of E. pekinensis was pretreated by two simple steps before CCC isolation, following the procedure: the total extract was extracted by classical solvent extraction using petroleum ether and ethyl acetate, respectively, and then the ethyl acetate extract was suspended using 95% ethanol, after being allowed to stand overnight, the sediment was obtained. Partial sediment (100 mg) was then directly separated by CCC with a two‐phase solvent system composed of chloroform‐95% ethanol‐water‐85% formic acid (50:50:50:5, v/v/v/v). About 22 mg of 3,3′‐dimethoxy ellagic acid (1), 12 mg of 3,3′‐di‐O‐methyl‐4‐O‐(β‐d ‐xylopyranosyl)ellagic acid (2), and 35 mg of ellagic acid (3) with purities of 96.0, 95.2, and 95.4% were obtained respectively in one step within 4 h. After being purified by washing with methanol, the purities of the three compounds obtained were all above 98%. The purities were determined by HPLC and their chemical structures were further identified by 1H and 13C NMR spectroscopy. The recoveries were calculated as 84.6, 85.7, and 89.5%, respectively. The result demonstrated that the present isolation method was rapid, economical and efficient for the preparative separation of polyphenols from E. pekinensis. 相似文献
126.
127.
Li‐Jun Yang Kun Jiang Jun‐Jie Tan Shi‐Jin Qu Hong‐Feng Luo Chang‐Heng Tan Da‐Yuan Zhu 《Helvetica chimica acta》2013,96(1):119-123
Chemical investigation on the stem and root of Melicope pteleifolia afforded three new prenylated benzene metabolites as racemic mixtures, named pteleifolins A–C ( 1 – 3 , resp.). Their gross structures were elucidated on the basis of spectroscopic analysis, especially 2D‐NMR experiments. An enantiomer resolution of (±)‐ 1 using chiral HPLC was performed, and the absolute configuration of the enantiomers were determined to be (+)‐(S)‐ 1 and (?)‐(R)‐ 1 by means of circular‐dichroism analysis. 相似文献
128.
AbstractAn operationally simple domino approach for the ruthenium-catalyzed synthesis of (E)-2,3′-bi(3H-indol)-3-one O-alkyl oximes by the region- and stereoselective three-component, four-molecule reactions of indoles with sodium nitrite and alkyl bromides under mild reaction condition in dimethylformamide is described. Remarkably, multiple bonds including C?C, C=N, and C?O bonds were conveniently formed in one pot. The reaction is tolerant to air and is atom economical, in accordance with the concept of modern green chemistry. 相似文献
129.
This work demonstrates an efficient way to prepare chiral propargylic alcohols by asymmetric addition of terminal Zn-acetylide to aldehydes catalyzed by bifunctional zinc-based complexes. The corresponding products with moderate to good yields and enantioselectivities were obtained in the absence of moisture-sensitive Ti(O i Pr)4. 相似文献
130.
Liang Qu Lu-Jing Ren Juan Li Guan-Nan Sun Li-Na Sun Xiao-Jun Ji Zhi-Kui Nie He Huang 《Applied biochemistry and biotechnology》2013,171(7):1865-1876
Growth and fermentation characteristics, biomass composition, lipid characterization and metabolic profiling analysis of two different Schizochytrium sp. strains, the original strain and the industrial adaptive strain, were investigated in the fed-batch fermentation process. The final cell biomass, total lipids content, docosahexanoic acid (DHA) content and DHA productivity of the adaptive strain were much higher than those of the original strain. The metabolic distinctions which extensively existed between these two strains were revealed by the score plot of principal component analysis. In addition, potential biomarkers responsible for discriminating different strains were identified as myo-inositol, histidine, alanine, asparagine, cysteine, and oxalic acid. These findings provided new insights into the industrial strain screening and further improvement of DHA production by Schizochytrium sp. 相似文献