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101.
Synthesis of Novel α‐(Acyloxy)‐α‐(quinolin‐4‐yl)acetamides by a Three‐Component Reaction between an Isocyanide,Quinoline‐4‐carbaldehyde,and Arenecarboxylic Acids 下载免费PDF全文
Jafar Taran Ali Ramazani Sang Woo Joo Katarzyna Ślepokura Tadeusz Lis 《Helvetica chimica acta》2014,97(8):1088-1096
Novel α‐(acyloxy)‐α‐(quinolin‐4‐yl)acetamides were synthesized by the Passerini three‐component reaction between an isocyanide, quinoline‐4‐carbaldehyde, and arenecarboxylic acids in H2O. The reactions were carried out in one pot at room temperature with quantitative yields. 相似文献
102.
Qinghao Jin Chul Lee Jin Woo Lee Jeong Yeon Choi Jin Tae Hong Youngsoo Kim Mi Kyeong Lee Bang Yeon Hwang 《Helvetica chimica acta》2014,97(8):1152-1157
A phytochemical investigation of the fruits of Melia azedarach led to the isolation of two new C‐seco‐nimbolinin‐type limonoids, 3α‐acetoxy‐1α,7α‐dihydroxy‐12α‐methoxynimbolinin ( 1 ) and 3α‐acetoxy‐1α,12α‐dihydroxy‐7α‐(2‐methylprop‐2‐enoyl)nimbolinin ( 2 ), together with eleven known compounds, 3 – 13 . Their structures were elucidated on the basis of extensive spectroscopic analysis, including 1H‐ and 13C‐NMR, HMQC, HMBC, NOESY, and HR‐FAB‐MS. 相似文献
103.
Thuy-Duong Nguyen-Phan Myoung Bok Song Eui Jung Kim Eun Woo Shin 《Research on Chemical Intermediates》2010,36(6-7):613-619
One-dimensional titania nanomaterials were synthesized by soft chemical processes in an alkali medium. The effect of alkali-treatment temperature on the morphology, porosity, and crystalline phase of TiO2 nanomaterials was investigated. Nanotubes having an opening end were observed when aging the sample at 130 °C, while conducting the process at 180 °C resulted in nanoribbons with a high aspect ratio. Post-treatment at 300 °C led to the partial transformation from tubular structures into nanoparticles or ribbons into nanobelts. While the monoclinic sodium hexatitanate and anatase crystal had a tubular structure, nanoribbons and nanobelt TiO2 also showed the presence of hydrogen titanate and sodium trititanate. High surface areas were achieved in as-prepared nanotubes and nanoribbons, 456.5 and 72.1 m2/g, respectively, and a drastic reduction was obtained upon post-treatment at 300 °C to 72.1 and 19.2 m2/g, respectively. 相似文献
104.
Peter Wipf Stefan Werner Grace H.C. Woo Corey R.J. Stephenson Maciej A.A. Walczak Claire M. Coleman Leslie A. Twining 《Tetrahedron》2005,61(48):11488-11500
The multi-component condensation of organozirconocene, aldimine and zinc carbenoid was applied to the stereoselective synthesis of cyclopropane amino acid derivatives. These compounds served as scaffolds for the preparation of a 46-member library. The C- and N-termini of the cyclopropane amino acid derivatives were diversified by condensations with ten amines and ten acylating agents, respectively. To improve yields and accelerate library synthesis, most products were prepared under microwave irradiation and purified by polymer-bound scavengers and SPE methodology. All compounds were analyzed by LC-MS and a representative selection was fully characterized. 相似文献
105.
Dr. Jong Wook Hong Yena Kim Dae Han Wi Seunghoon Lee Su‐Un Lee Young Wook Lee Prof. Sang‐Il Choi Prof. Sang Woo Han 《Angewandte Chemie (International ed. in English)》2016,55(8):2753-2758
A synthesis strategy for the preparation of ultrathin free‐standing ternary‐alloy nanosheets is reported. Ultrathin Pd‐Pt‐Ag nanosheets with a thickness of approximately 3 nm were successfully prepared by co‐reduction of the metal precursors in an appropriate molar ratio in the presence of CO. Both the presence of CO and the interplay between the constituent metals provide fine control over the anisotropic two‐dimensional growth of the ternary‐alloy nanostructure. The prepared Pd‐Pt‐Ag nanosheets were superior catalysts of ethanol electrooxidation owing to their specific structural and compositional characteristics. This approach will pave the way for the design of multicomponent 2D nanomaterials with unprecedented functions. 相似文献
106.
The two-photon-resonant first hyperpolarizabilities associated with hyper-Rayleigh and hyper-Raman scattering are reported for 4-dimethylamino-4-nitrostilbene in 1,4-dioxane, dichloromethane, acetonitrile, and methanol, and for an ionic analog, 4-N,N-bis(6-(N,N,N-trimethylammonium)-hexyl)amino-4-nitrostilbene dibromide in methanol and water. Resonance Raman and hyper-Raman excitation profiles are also measured and modeled. The resonance Raman and hyper-Raman spectra show very similar relative intensities which do not vary much as the excitation frequency is tuned across the lowest-energy strong linear absorption band, suggesting that a single resonant electronic state dominates the one- and two-photon absorptions in this region. The absorption, resonance Raman, and hyper-Raman profiles can be simulated reasonably well with a common set of parameters. The peak resonant (absolute value of beta)2, measured by hyper-Rayleigh scattering, varies by about 50% over the range of solvents examined and shows a weak correlation with the linear absorption maximum, with the redder-absorbing systems exhibiting larger peak hyperpolarizabilities. The experimental hyper-Rayleigh intensities are higher than those calculated, possibly reflecting contributions from nonresonant electronic states. 相似文献
107.
Hyoun Woo Kim Seung Hyun Shim Jong Woo Lee Jae Young Park Sang Sub Kim 《Chemical physics letters》2008,456(4-6):193-197
We introduce a simple method of synthesizing SnO2 nanowire-Bi2Sn2O7 nanoparticle composites based on the principle that SnO2 nanowires can be grown by using Bi as catalysts. A mixture of Bi and Sn powders was thermally evaporated, and the effects of growth temperature on the morphology and structure of the products were investigated. We obtained Bi2Sn2O7-tipped SnO2 nanowires at 700 °C through a vapor–liquid–solid (VLS) process, whereas particle-free SnO2 nanowires were produced at higher temperatures. We have investigated the oxygen sensing properties of the as-synthesized product. 相似文献
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