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91.
Asymmetric Total Synthesis of (+)‐Bermudenynol,a C15 Laurencia Metabolite with a Vinyl Chloride Containing Oxocene Skeleton,through Intramolecular Amide Enolate Alkylation
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Gyudong Kim Dr. Te‐ik Sohn Prof. Dr. Deukjoon Kim Dr. Robert S. Paton 《Angewandte Chemie (International ed. in English)》2014,53(1):272-276
A substrate‐controlled asymmetric total synthesis of (+)‐bermudenynol, a compact and synthetically challenging C15 Laurencia metabolite that contains several halogen atoms, is reported. The oxocene core, which contains a vinyl chloride, was constructed by an efficient and highly stereoselective intramolecular amide enolate alkylation (IAEA). This result showcases the broad utility of the IAEA methodology as a useful alternative for cases in which the ring‐closing metathesis is inefficient. 相似文献
92.
Yun Zhang Yahong Xie Juan Li Te Bai Jide Wang 《Journal of Sol-Gel Science and Technology》2014,71(1):38-42
The CuBi2O4/TiO2 p–n heterojunction composites were obtained by in situ sol–gel coating process using prepared CuBi2O4 powders and titania colloid. The obtained CuBi2O4/TiO2 composites were characterized by XRD, SEM, BET and UV–vis diffuse reflectance spectroscopy. Their photocatalytic and adsorption activities were evaluated by degradations and adsorptions of methyl orange and congo red. Results showed that some compositions of prepared p–n heterojunction composites exhibited much higher photocatalytic activity and absorption performance than pure CuBi2O4 or pure TiO2, demonstrating that the formation of p–n heterojunction between the two materials plays an important role in improving photocatalytic activity and adsorption performance. 相似文献
93.
94.
A. R. Bishop R. L. Martin K. A. Müller Z. Tešanović 《Zeitschrift für Physik B Condensed Matter》1989,76(1):17-24
We present a combined overview of current experimental knowledge and theoretical understanding of high temperature superconductivity based on the charge transfer excitation model. Our model is capable of rationalizing a great variety of experimental information and suggests directions to follow in designing even higherT
c materials. 相似文献
95.
Natić Maja M. Baošić Rada M. Milojković-Opsenica Dušanka M. Tešić Živoslav Lj. 《平面色谱法杂志一现代薄层色谱法》2005,18(5):344-348
JPC – Journal of Planar Chromatography – Modern TLC - Experimental RM values for two series of ß-diketonato complexes, M(acac)3-n(phacphac)n and M(acac)3-n(phSacphSac)n, where M... 相似文献
96.
Ya‐Ching Shen Yu‐Chi Lin Yuan‐Bin Cheng Chia‐Ju Chang Ting‐Wei Lan Shorong‐Shii Liou Ching‐Te Chien Chia‐Ching Liaw Ashraf Taha Khalil 《Helvetica chimica acta》2008,91(3):483-494
Seven new oxygenated lignans, kadsuphilins G–M ( 1 – 7 , resp.), were isolated by chromatographic fractionation of an AcOEt extract of the aerial part of Kadsura philippinensis including four compounds with a dibenzocyclooctadiene skeleton, two with a bicyclooctane ring system, and one of 1,4‐biphenyldimethylbutane type. The structures of the isolated compounds were elucidated through extensive spectroscopic analyses, particularly 2D‐NMR experiments (HMQC, HMBC, and NOESY). The configuration of the chiral centers and the biphenyl moiety were determined by NOESY as well as CD spectroscopy, respectively. 相似文献
97.
Tesić M Wicki J Poon DK Withers SG Douglas DJ 《Journal of the American Society for Mass Spectrometry》2007,18(1):64-73
Tandem mass spectrometry has been used to compare gas-phase and solution binding of three small-molecule inhibitors to the wild type and three mutant forms of the catalytic domain of Cex, an enzyme that hydrolyses xylan and xylo-oligosaccharides. The inhibitors, xylobiosyl-deoxynojirimycin, xylobiosyl-isofagomine lactam, and xylobiosyl-isofagomine consist of a common distal xylose linked to different proximal aza-sugars. The three mutant forms of the enzyme contain the substitutions Asn44Ala, Gln87Met, and Gln87Tyr that alter the binding interactions between Cex and the distal sugar of each inhibitor. An electrospray ionization (ESI) triple quadrupole MS/MS system is used to measure the internal energies, DeltaE(int), that must be added to gas-phase ions to cause dissociation of the noncovalent enzyme-inhibitor complexes. Collision cross sections of ions of the apo-enzyme and enzyme-inhibitor complexes, which are required for the calculations of DeltaE(int), have also been measured. The results show that, in the gas phase, enzyme-inhibitor complexes have more compact, folded conformations than the corresponding apo-enzyme ions. With the mutant enzymes, the effects of substituting a single residue can be detected. The energies required to dissociate the gas-phase complexes follow the same trend as the values of DeltaG0 for dissociation of the complexes in solution. This trend is observed both with different inhibitors, which probe binding to the proximal sugar, and with mutants of Cex, which probe binding to the distal sugar. Thus the gas-phase complexes appear to retain much of their solution binding characteristics. 相似文献
98.
Ma Te Inagaki Tetsuya Yoshida Masato Ichino Mayumi Tsuchikawa Satoru 《Cellulose (London, England)》2021,28(17):10787-10801
Cellulose - Strain measurement is critical for wood quality evaluation. Using conventional strain gauges constantly is high cost, also challenging to measure precious wood materials due to the use... 相似文献
99.
Quantum information processing based on Rydberg atoms emerged as a promising direction two decades ago.Recent experimental and theoretical progresses have shined exciting light on this avenue.In this concise review,we will briefly introduce the basics of Rydberg atoms and their recent applications in associated areas of neutral atom quantum computation and simulation.We shall also include related discussions on quantum optics with Rydberg atomic ensembles,which are increasingly used to explore quantum computation and quantum simulation with photons. 相似文献
100.
A. O. Badrutdinov E. M. Zarubezhnova Yu. I. Talanov G. B. Teĭtel’baum G. Jakob 《Journal of Experimental and Theoretical Physics》2007,105(1):79-85
Electron spin resonance is studied in films of La1?x Ca x MnO3 manganites with compositions in the vicinity of the calcium content x = 0.5, in which the phase separation is most clearly pronounced. It is found that the La0.5Ca0.5MnO3 manganite undergoes different types of phase separation: (i) at temperatures above the Curie point, ferromagnetic regions exist in the paramagnetic phase; and (ii) at temperatures below the Néel point, antiferromagnetic microregions coexist with ferromagnetic microregions. Two types of ferromagnetic domains with different magnetization orientations are revealed In the temperature range between the Curie and Néel points. 相似文献