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11.
AbstractAnilines are rapidly, often within 60?minutes, converted into the corresponding phenols in up to 87% isolated yield. The presented experimentally simple protocol display broad compatibility with a variety of functional groups, and in particular, well suited for the preparation of methyl-substituted phenols. Such phenols are not easily available by other synthetic approaches. The formation of phenolic radical coupling products was not observed even for activated anilines using this open flask method. 相似文献
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Triple-layer omnidirectional reflectors (ODRs) consisting of a semiconductor, a quarter-wavelength transparent dielectric layer, and a metal have high reflectivities for all angles of incidence. Internal ODRs (ambient material's refractive index n > 1.0) are demonstrated that incorporate nanoporous SiO2, a low-refractive-index material (n = 1.23), as well as dense SiO2 (n = 1.46). GaP and Ag serve as the semiconductor and the metal layer, respectively. Reflectivity measurements, including angular dependence, are presented. Calculated angle-integrated TE and TM reflectivities for ODRs employing nanoporous SiO2 are R(int)/TE = 99.9% and R(int)/TM = 98.9%, respectively, indicating the high potential of the ODRs for low-loss waveguide structures. 相似文献
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Grotenbreg GM Kronemeijer M Timmer MS El Oualid F van Well RM Verdoes M Spalburg E van Hooft PA de Neeling AJ Noort D van Boom JH van der Marel GA Overkleeft HS Overhand M 《The Journal of organic chemistry》2004,69(23):7851-7859
A practical gram-scale and high-yielding synthesis of the antimicrobial peptide gramicidin S is presented. An Fmoc-based solid-phase peptide synthesis protocol is employed for the generation of the linear decapeptide precursor, which is cyclized in solution to afford the target compound. The versatility of our method is demonstrated by the construction of eight gramicidin S analogues (15a-h) having nonproteinogenic sugar amino acid residues (4-7) incorporated in the turn regions. 相似文献
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Friedrich MG Giebeta F Naumann R Knoll W Ataka K Heberle J Hrabakova J Murgida DH Hildebrandt P 《Chemical communications (Cambridge, England)》2004,(21):2376-2377
Membrane-bound cytochrome c oxidase was attached to an electrode via a His-tag linker and studied by surface enhanced resonance Raman spectroscopy, demonstrating intact redox site structures and electron transfer between the electrode and the immobilized enzyme. 相似文献
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Renate M van WellMarlies E.A Meijer Herman S OverkleeftJacques H van Boom Gijsbert A van der Marel Mark Overhand 《Tetrahedron》2003,59(14):2423-2434
The synthesis of three methylene bridged sugar amino acids is described. Key transformations in the synthetic strategy are a CO-insertion on fully protected ribose, an aldol condensation with formaldehyde and an oxetane forming cyclisation step. A novel Leu-enkephalin analogue containing the δ-SAA 1 was prepared using standard solution phase peptide chemistry. 相似文献
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