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61.
Akio Toshimitsu Toshiaki Aoai Hiroto Owada Sakae Uemura Masaya Okano 《Tetrahedron》1985,41(22):5301-5306
The reaction of phenylselenenyl chloride with olefins in aqueous acetonitrile affords β-hydroxyalkyl phenyl selenides in excellent yields, providing the most convenient method for hydroxyselenation of olefins so far reported. When the reaction was applied to conjugated dienes, monohydroxyselenated products were obtained in good to excellent yields. From non-conjugated dienes, on the other hand, cyclic ethers containing two phenylseleno groups were produced in good to excellent yields, the first step of this reaction being the hydroxyselenation of one double bond. 相似文献
62.
Oxidation of several linear conjugated dienes with tellurium (IV) oxide and lithium bromide in acetic acid affords an isomeric mixture of the corresponding diacetoxyalkenes (1,2- and 1,4-addition products), 1,4-isomer being highly selectively produced when the ratio of LiBr/TeO2, is 5–10. 相似文献
63.
Critchley K Jeyadevan JP Fukushima H Ishida M Shimoda T Bushby RJ Evans SD 《Langmuir : the ACS journal of surfaces and colloids》2005,21(10):4554-4561
Surface modification using light is one of the most powerful methods for controlling the physical and chemical properties offunctionalized surfaces. In this paper, we report on systems where soft UV irradiation (lambda = 365 nm) converts a "low" activity fluorocarbon to a "high" activity amine-functionalized surface. An amine-functionalized SAM (self-assembled monolayer) is first masked using a tertiary amine catalyzed reaction with an N-hydroxysuccinimidyl carbonyl reagent. This mild, room-temperature reaction introduces a hydrophobic photocleavable nitrobenzyl "protecting group" terminated with a fluorocarbon end-chain. UV irradiation (lambda = 365 nm) of this hydrophobic/fluorocarbon surface cleaves the nitrobenzyl residue, returning the surface to the original hydrophilic/amine-functionalized state. This provides a mild, generic method of producing surfaces with hydrophilic/hydrophobic patterns or patterned with amine functional residues. Two different protecting groups, one terminated with a single and the other with three fluorocarbon end chains, are compared. In the case of the more bulky protecting group, only a small proportion of the amine residues react, but the surface is equally hydrophobic and the amine residues equally well shielded from further reaction. Surfaces are characterized by X-ray photoelectron spectroscopy, ellipsometry, surface potential, and contact angle measurements. Images of the photopatterned SAMs were obtained using scanning electron microscopy. 相似文献
64.
Treatment of several cyclic olefins, β-pinene, allylbenzene, and estragole with palladium(II) salt in acetic acid in the presence of t-butyl hydroperoxide and tellurium(IV) oxide afforded mainly the corresponding allylic acetates. The reaction proceeded catalytically with palladium(II) salt, t-BuOOH working as a reoxidizing agent. 相似文献
65.
66.
Yasuhiro Matoba Takashi Kagayama Yasutaka Ishii Masaya Ogawa 《Magnetic resonance in chemistry : MRC》1981,17(2):144-147
The 13C NMR spectra of a series of epoxides derived from endo- and exo-dicyclopentadiene and their partially hydrogenated compounds were determined to examine the substituent effects arising from the introduction of the oxirane ring in comparison with those found in other ring systems. The 13C signals of some epoxides were assigned by using lanthanide shift reagents. Characteristic substituent effects exerted by an oxirane ring were demonstrated. Marked steric γ-effects of ?8—13 ppm were observed at the bridge carbon signal in the bicyclo[2.2.1]heptane skeleton. Differences were found in the substituent effects between endo- and exo-dicyclopentadiene epoxides, and have been discussed in relation to the molecular geometry. 相似文献
67.
We demonstrate that ultrasmall double-layer photonic-crystal-slab cavities exhibit a very high-Q value for a wide range of the layer spacing, which enables us to realize unique optomechanical coupling. By mechanically varying the separation, we can achieve extraordinarily large wavelength conversion. In addition, the light stored in the cavity can generate a large radiation force. We show that this system exhibits extremely high energy conversion efficiency between optical and mechanical energy, leading to a novel approach for the optomechanical control of light and matter. 相似文献
68.
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70.
Ikuo Kawashima Hiroaki Imoto Masatoshi Ishida Hiroyuki Furuta Shunsuke Yamamoto Masaya Mitsuishi Susumu Tanaka Toshiki Fujii Kensuke Naka 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(34):11812-11816
Dibenzo[b,f]arsepins possessing severely distorted cores compared to those of other heteropins were synthesized. These derivatives exhibited dual photoluminescence in the green‐to‐red region (500–700 nm) and the near‐ultraviolet region (<380 nm), which could be attributed to the planarization of the arsepin core in the lowest singlet excited (S1) state. The computational approach for the assessment of the aromatic indices revealed that the dibenzoarsepins studied show aromaticity (8π system) in the S1 states in line with Baird's rule. The lone pair electrons of the arsenic atoms play a crucial role in the aromaticity in the S1 states. 相似文献