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121.
Jing Xiang Er-Xiao Sun Chun-Xia Lian Wei-Cheng Yuan Jin Zhu Qiwei Wang Jingen Deng 《Tetrahedron》2012,68(24):4609-4620
Chemoselective transfer hydrogenation of conjugated nitroalkenes catalyzed by [RhCl2Cp1]2–diamine complex (Cp1=η5-C5Me5) using HCOOH/Et3N (5:2) (TEAF) as a hydrogen source was realized. A variety of nitrostyrenes, β-methyl nitrostyrenes, and 3-methyl-4-nitro-5-alkenyl-isoxazoles were reduced smoothly in good to excellent yields in short reaction time. Other functional groups are inert under the reaction conditions. 相似文献
122.
HanLi Lian 《Physica B: Condensed Matter》2011,406(22):4278-4282
Effects of two types of three-site interaction, i.e., XZX+YZY and XZY−YZX, on Loschmidt Echo (LE) of a central spin coupled to an XY spin chain are studied. The dynamical evolution behaviors of the LE are investigated analytically and numerically. The XZX+YZY type of three-site interaction (α1) can shift the critical points of the magnetic field λ. At the critical points |λ−α1|=1, the decay of the LE is enhanced. The role of the XZY−YZX type of three-site interaction (α2) depends on its strength. In some specific intervals, α2 can remarkably delay the decay of the LE. 相似文献
123.
Jin ZHAI Feng Lian BAI Qing Guo HE Ying Shun LI Lei JIANG Tong LIN Organic Solid Laboratory Research Center for Molecular Sciences Institute of Chemistry The Chinese Academy of Science Beijing 《中国化学快报》2000,11(9)
The hotSPOt in the fields of molecular films focuses on highly ordered, ultrathin filmswith molecularly controllable surface properties. It is attractive tO stUdy supramolecularfunctional POlymeric materials with suitable physical properties and abilities to formorganized superstrUctures at the interfacesl'2'3A. Dendritic macromolecules are a kind ofmaterials which is capable of self-organizing into superstrUctUres'. So a new dendrimerlike POly(Phenylene vinylene)- --hyperbranched conj "… 相似文献
124.
Based on the previous studies, a procedure has been established for the analysis of palladium in reprocessing waste solution
of spent nuclear fuel. The sample was contacted with the extractant solution which consisted of benzo-15-crown-5, chloroform,
and potasium iodide at room temperature for 1 minute. The extract was dehydrated by anhydrous Na2SO4 and measured spectrophotometrically versus water at 360 nm. The extractant solution used can be regenerated by KI (or NaI
and Lil) for reuse. The percent extraction of palladium and apparent molar abaorptivity are 96–100% and 4·104, respectively. The composition of extracted complex is [KB15C5)2]2·(Pd2I6). 相似文献
125.
5-Oxo-compound 7 and its epimer 8 prepared from epoxidation of methyl arteannuinate followed by rearrangement with BF3 · Et2O exhibited a negative and a positive Cotton effect near 294 nm in CD, respectively, a cis A/B ring fusion for 7 and a trans A/B ring fusion for 8 were assigned. It is consistent with the prediction from the octant rule. Therefore the cis A/B ring fusion for arteannuic acid is established. In a similar way, compounds 13a, b and 14 were obtained from the dihydroarteannuinate. Compounds 13a, b showed the same signs as that of 7 and compound 14 as that of 8. Thus the cis A/B ring configuration of arteannuic acid is further proved. 相似文献
126.
Rusin O Alpturk O He M Escobedo JO Jiang S Dawan F Lian K McCarroll ME Warner IM Strongin RM 《Journal of fluorescence》2004,14(5):611-615
The detection of saccharides in biological media is of great current importance for the monitoring of disease states. We have previously reported that solutions of boronic acid-functionalized macrocycles form acyclic oligomeric materials in situ. The oligomers contain fluorescent xanthene moieties. Current efforts are aimed at modulating the spectroscopic responses of these materials for the analysis of specific sugars. We describe conditions whereby the xanthene boronic acids exhibit high colorimetric fructose selectivity. In contrast, at physiological levels selective glucose monitoring can be achieved via fluorescence. Additionally, we describe a method which exhibits promise for detecting both glucose and fructose at dual wavelengths in the UV-Vis region. Mechanistic rationale for each of these findings is presented. 相似文献
127.
128.
Lian Peng Tong ;Jing Nan Cui ;Wei Min Ren ;Xing Yong Wang ;Xu Hong Qian 《中国化学快报》2008,19(10):1179-1182
Regio- and enantioselective reduction of substituted acenaphthenequinones were conducted under mild reaction conditions using plant enzymatic systems. A screening of 15 plants allowed the selection of two suitable plants fulfilling enantiocomple- mentarity. The (+)- and (-)-mono hydroxyacenaphthenones were achieved with high conversion and good enantiomeric purity using peach (Prunus persica (L.) Batsch., conversion 98%, 71% ee) and carrot (Daucus carota L., conversion 95%, 81% ee), respectively. 相似文献
129.
Isovaleroyl oxokadsurane, a novel dibenzocyclooctadiene lignan pos-sessing a spirobenzofuranoid skeleton was isolated from the stems of Kadsura coccinea.Its structure and relative configuration were determined by X-ray diffraction analysis. 相似文献