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111.
Several transition metal-mediated oxidations using hypervalent iodine species are reported. A convenient procedure for preparation of iodylarenes via RuCl3-catalyzed oxidation of iodoarenes has been developed. This procedure allows the generation of highly reactive monomeric iodine(V) species, which are excellent oxidants toward alcohols and hydrocarbons in situ. A broad range of substrates can be oxidized to carbonyl compounds by a tandem catalytic system based on the Ru(III)-catalyzed reoxidation of ArIO to ArIO2 using Oxone® as oxidant. It was shown that electrophilic iodine(III) species, originating from oligomeric iodosylbenzene sulfate (PhIO)3SO3, are efficient oxygenating agents in catalytic oxidation of aromatic hydrocarbons in the presence of metalloporphyrin complexes. 相似文献
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113.
Sabir Jacquir Stéphane Binczak Jean-Marie Bilbault Viktor Kazantsev Vladimir Nekorkin 《Nonlinear dynamics》2006,44(1-4):29-36
An electrical circuit is proposed to realize an unidirectional coupling between two cells, mimicking chemical synaptic coupling.
Each cell represents the FitzHugh–Nagumo (FHN) model of neuron with a modified exitability (MFHN). We present experimental
results on frequency doublings and on the chaotic dynamics depending on the coupling strength in a master–slave configuration.
In all experiments, we stress the influence of the coupling strength on the control of the slave neuron. 相似文献
114.
We describe affine functions on spaces with an upper curvature bound. 相似文献
115.
Viktor L. Ginzburg 《Mathematische Zeitschrift》1992,210(1):625-640
The Research was partially supported by NSF Grant DMS 8505550 相似文献
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Sergey G. Il’yasov Viktor A. Cherkashin Gennady V. Sakovich Dmitri A. Parkhomenko 《Chemical Papers》2015,69(11):1445-1453
The chemical structures of Miscanthus var. ‘Soranovskii’ lignin fractions released via extraction of lignin from the lignocellulosic feedstock using moderately heated acetone under atmospheric pressure, without acidic and alkaline catalysts, were studied. A blend of Miscanthus stems and leaves was pretreated with water under thermobaric conditions. The acetone organosolv process subsequently afforded a substance related to a lignin-like matter-acetone organosolv Miscanthus lignin (AOML). Non-destructive analytical techniques such as FTIR spectroscopy, gas chromatography-mass spectrometry, size-exclusion chromatography, and 2D NMR were used. The IR and NMR spectroscopies revealed the AOML structure to comprise all the three major types of phenylpropane units: guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H). The resultant acetone-organosolv lignin exhibits good solubility in polar solvents, moderate solubility in aromatic chemicals, and is insoluble in non-polar solvents, exhibiting the physicochemical properties of a thermoplastic polymer with a softening point of 67.0°C (onset 33.0°C, endset 81.5°C). 相似文献
119.
Dr. Pilar Ventosa‐Andrés Dr. Agustina La‐Venia Dr. Carlos Alfonso Barea Ripoll Dr. Ludmila Hradilová Dr. Viktor Krchňák 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):13112-13119
Herein, we describe the synthesis of molecular scaffolds consisting of medium‐sized fused heterocycles using amino acids, which are some of the most useful building blocks used by nature as well as chemists to create structural diversity. The acyclic precursors were assembled by using traditional Merrifield solid‐phase peptide synthesis, and cyclization was carried out through acid‐mediated tandem endocyclic N‐acyliminium ion formation, followed by nucleophilic addition with internal nucleophiles. The synthesis of molecular scaffolds consisting of seven‐, eight‐, and nine‐membered rings proceeded with full stereocontrol of the newly generated stereogenic center in most cases. 相似文献
120.
Frontispiece: Monitoring and Understanding the Paraelectric–Ferroelectric Phase Transition in the Metal–Organic Framework [NH4][M(HCOO)3] by Solid‐State NMR Spectroscopy 下载免费PDF全文