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101.
Takei I Nishibayashi Y Ishii Y Mizobe Y Uemura S Hidai M 《Chemical communications (Cambridge, England)》2001,(22):2360-2361
Chiral ruthenium(II) complexes, RuCl2(PPh3)(oxazolinylferrocenylphosphine), have been found to be effective catalysts for asymmetric hydrosilylation of ketoximes to give the corresponding primary amines in good yields with high enantioselectivities (up to 89% ee) after acid hydrolysis. 相似文献
102.
[structure: see text]. Michael addition of various enolates toward gamma-CH(3-n)F(n)-alpha,beta-unsaturated ketones (n = 1-3) was proven to smoothly furnish the 1,4-adducts with high si face selectivities which monotonously decreased by reduction in the number of fluorines. Although the Felkin-Anh model correctly anticipates the present stereochemical outcome only with E-acceptors, the hyperconjugative stabilization of transition states by electron donation from the allylic substituents (the Cieplak rule) successfully explains the pi-facial preference of both acceptors at least in a qualitative level. 相似文献
103.
A new reconstruction method called sampled pattern matching (SPM) was applied to the image reconstruction of an electrical
capacitance computed tomography in powder flow in a vertical pipe for petroleum refinery process. This new method is able
to achieve stable convergence without the use of an empirical value. Experiments were carried out using fluid catalytic cracking
(FCC) catalysts as powder with two air volume flow rates and four powder volume flow rates to measure the capacitance of a
pipe cross section. The SPM method is compared with conventional methods in terms of volume fraction, residual capacitance,
and correlation capacitance. Overall, the SPM method proved superior to conventional methods without any empirical value because
SPM achieves accurate reconstruction by using an objective function that is calculated as the inner product calculation between
the experimental capacitance and the reconstructed image capacitance. 相似文献
104.
Dr. Toshiharu Ishizaki Hideaki Karasaki Dr. Yuto Kage Misaki Kamioka Yitong Wang Dr. Shigeki Mori Prof. Dr. Naoto Ishikawa Prof. Dr. Takamitsu Fukuda Prof. Dr. Hiroyuki Furuta Prof. Dr. Soji Shimizu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(49):12686-12692
A novel pyrrolopyrrole azadipyrrin ( Janus-PPAD ) with Janus duality was synthesized by a Schiff base–forming reaction of diketopyrrolopyrrole. The orthogonal interactions of the hydrogen-bonding ketopyrrole and metal-coordinating azadipyrrin moieties in Janus-PPAD enabled the metal ions to be arranged at regular intervals: zinc(II) and cobalt(II) coordination provided metal-coordinated Janus-PPAD dimers, which can subsequently form hydrogen-bonded one-dimensional arrays both in solution and in the solid state. The supramolecular assembly of the zinc(II) complex in solution was investigated by 1H NMR spectroscopy based on the isodesmic model, in which a binding constant for the elongation of assemblies is constant. Owing to the tetrahedral coordination, in the solid state, the cobalt(II) complex exhibited a slow magnetic relaxation due to the negative D value of −27.1 cm−1 with an effective relaxation energy barrier Ueff of 38.0 cm−1. The effect of magnetic dilution on the relaxation behavior is discussed. The relaxation mechanism at low temperature was analyzed by considering spin lattice interactions and quantum tunneling effects. The easy-axis magnetic anisotropy was confirmed, and the relevant wave functions were obtained by ab initio CASSCF calculations. 相似文献
105.
The reaction of anilines, benzaldehydes, and ethyl 3,3-diethoxypropionate in the presence of Yb(OTf)3 proceeded under mild reaction conditions to give dihydropyridines (DHPs). We have found that the reaction depended on the solvent and the DHPs were obtained selectively in 1,4-dioxane as a solvent. Various 2,6-unsubstituted DHPs were synthesized in one pot in satisfactory yields. 相似文献
106.
An appropriate solvent to perform the original Simmons–Smith reaction was reinvestigated. Among available solvents, cyclopentyl methyl ether (CPME), a recently commercialized ethereal solvent, was found to be the best so far. Compared with Et2O under reflux – the commonest conditions – reaction completion in CPME at 50 °C was about 10 times faster. The product yields and selectivities were mostly identical to those with Et2O, but were better in some cases; e.g. 13–56% with 2‐cyclohexenol. The good performance of CPME should be mainly due to its moderate polarity and high boiling point. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
107.
We develop the exact WKB analysis of an M2P1T (merging two simple poles and one simple turning point) Schrödinger equation. Our emphasis is put on the analysis of the singularity structure of its Borel transformed WKB solutions near fixed singular points relevant to the two simple poles contained in the potential of the equation. In Part I, we focus our attention on the construction and analytic properties of a WKB-theoretic transformation that transforms an M2P1T equation to an algebraic Mathieu equation. That transformation plays an important role in Part II ([7]) when we discuss the singularity structure of Borel transformed WKB solutions of an M2P1T equation. 相似文献
108.
Condensation of p-nitrophenyl 2,3,4-tri-O-benzoyl-β-D-glucopyranoside 3 with 2,3,4-tri-O-(chlorosulfonyl)-β-D-xylopyranosyl chloride by the Koenigs-Knorr method afforded the α-linked product in a high yield. Dechlorosulfation with sodium iodide and debenzoylation by the Zemplen method gave crystalline p-nitrophenyl 6-O-(α-D-xylopyranosyl)-β-D-glucopyranoside 7. Compound 3 was condensed with 2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide in the presence of mercury (II) cyanide in acetonitrile, and after debenzoylation, crystalline p-nitrophenyl 6-O-(β-D-xylopyranosyl)-β-D-glucopyranoside 10 was obtained. 相似文献
109.
We extract large-angle elastic differential cross sections (DCSs) for electrons scattering from partially aligned O2+ and CO2+ molecules using rescattering photoelectrons generated by infrared laser pulses. The extracted DCSs are in good agreement with those calculated theoretically, demonstrating that accurate DCSs for electron-ion scattering can be extracted from the laser-induced rescattering spectra, thus paving the way for dynamic imaging of chemical reactions by rescattering photoelectron spectroscopy. 相似文献
110.
Superconducting Double Perovskite Bismuth Oxide Prepared by a Low‐Temperature Hydrothermal Reaction 下载免费PDF全文
Mirza H. K. Rubel Prof. Akira Miura Prof. Takahiro Takei Prof. Nobuhiro Kumada M. Mozahar Ali Prof. Masanori Nagao Prof. Satoshi Watauchi Prof. Isao Tanaka Prof. Kengo Oka Prof. Masaki Azuma Prof. Eisuke Magome Prof. Chikako Moriyoshi Prof. Yoshihiro Kuroiwa Prof. A. K. M. Azharul Islam 《Angewandte Chemie (International ed. in English)》2014,53(14):3599-3603
Perovskite‐type structures (ABO3) have received significant attention because of their crystallographic aspects and physical properties, but there has been no clear evidence of a superconductor with a double‐perovskite‐type structure, whose different elements occupy A and/or B sites in ordered ways. In this report, hydrothermal synthesis at 220 °C produced a new superconductor with an A‐site‐ordered double perovskite structure, (Na0.25K0.45)(Ba1.00)3(Bi1.00)4O12, with a maximum Tc of about 27 K. 相似文献