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951.
Palladium-catalyzed carbonylation of tosylates with phenyl formate is described. This procedure needs neither external carbon monoxide nor any pressure-resistant apparatus. A variety of cyclic and acyclic alkenyl tosylates can be converted into the corresponding phenyl esters in good yields. Furthermore, this method is effective for the one-pot synthesis of α,β-unsaturated amides. 相似文献
952.
Dr. Haruhisa Kikuchi Kosuke Kawai Yota Nakashiro Takayuki Yonezawa Kumi Kawaji Prof. Dr. Eiichi. N. Kodama Prof. Dr. Yoshiteru Oshima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(4):1106-1112
The structural diversity of natural products and their derivatives have long contributed to the development of new drugs. However, the difficulty in obtaining compounds bearing skeletally novel structures has recently led to a decline of pharmaceutical research into natural products. This paper reports the construction of a meroterpenoid-like library containing 25 compounds with diverse molecular scaffolds obtained from diversity-enhanced extracts. This method constitutes an approach for increasing the chemical diversity of natural-product-like compounds by combining natural product chemistry and diversity-oriented synthesis. Extensive pharmacological screening of the library revealed promising compounds for anti-osteoporotic and anti-lymphoma/leukemia drugs. This result indicates that the use of diversity-enhanced extracts is an effective methodology for producing chemical libraries for the purpose of drug discovery. 相似文献
953.
Kenji Kinashi Yusuke Miyashita Kenji Ishida Yasukiyo Ueda 《Journal of Physical Organic Chemistry》2012,25(5):427-430
A composite film containing photochromic spiropyran dye 1 and BaFCl:Eu was developed for X‐ray dose measurement at a level of a few dozen gray (Gy). The reflectance intensity at selected wavelength, obtained from X‐radiation, can be satisfactorily related to the absorbed dose in the range of 0?30 Gy. The composite film shows significant color change in the visible region, and the sensitivity of the composite to the absorbed dose was achieved based on the high molar extinction coefficient of the photomerocyanine form of dye 1. For practical application, the photoinduced blue area indicates an X‐radiated area, and the initial pale pink area indicates an unexposed area. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
954.
955.
Shichen Liu Shingo Kobayashi Shin-nosuke Nishimura Tomoya Ueda Masaru Tanaka 《Journal of polymer science. Part A, Polymer chemistry》2021,59(21):2559-2570
Poly(2-methyl-2-oxazoline) (PMeOx), poly(2-ethyl-2-oxazoline) (PEtOx), poly(2-n-butyl-2-oxazoline) (PBuOx), and poly(2-phenyl-2-oxazoline) (PPhOx) are selected as poly(2-oxazoline) (POX) models to study the effect of pendant groups on their blood compatibility and hydration states. A comprehension of this can provide a perspective for understanding the biocompatibility of PMeOx and PEtOx in water-polymer interactions and may inspire the development of novel blood-compatible POX derivatives. The aforementioned four POXs are grafted onto glass substrates via photo-grafting, and their blood compatibility is estimated via platelet adhesion and the degree of denaturation of the adsorbed fibrinogen. The hydration states of the POXs are investigated using differential scanning calorimetry and attenuated total reflection infrared spectroscopy. Intermediate water is found to be present in hydrated PMeOx and PEtOx, but is observed to be scarce in hydrated PBuOx and PPhOx. This could be the reason for the biocompatibility of PMeOx and PEtOx. The carbonyl groups in PMeOx and PEtOx can be fully hydrated. However, in PBuOx and PPhOx, water mainly exists as bulk water. The hydration of the carbonyl groups is hindered by the bulky side chains, and IW cannot be generated. 相似文献
956.
957.
Large single crystals of β-Mn2V2O7 are successfully grown at a slow cooling rate using flux method in a closed crucible. The grown crystals exhibit a characteristic morphology with natural (1 1 0) and (3 5 0) facets. X-ray diffraction and chemical analyses show that the grown crystals have high quality. 相似文献
958.
Feng Wang Dr. Wataru Ueda Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(3):742-753
The synthesis and characterization of nanostructured MoO3 with a thickness of about 30 nm and a width of about 450 nm are reported. The composition formula of the MP (precipitation method) precursor was estimated to be [(NH4)2O]0.169?MoO3? (H2O)0.239. The calcination of the precursor in air afforded nanostructured pellets of the α‐MoO3 phase. The nanostructured MoO3 catalyst exhibited high efficiency in catalyzing the benzylation of various arenes with substituted benzyl alcohols, which were strikingly different to common bulk MoO3. Most reactions offered >99 % conversion and >99 % selectivity to monoalkylated compounds. MoO3 is a typical acid catalyst. However, the benzylation reaction over nanostructured MoO3 does not belong to the acid‐catalyzed type or defect site‐catalyzed type, since the catalyst has no acidity and defect site on surface. Characterization with thermal, spectroscopic, and electronic techniques reveal that the catalyst contains fully oxygen‐coordinated MoO6 octahedrons on the surface but partially reduced species (Mo5+) within the bulk phase. The terminal oxygen atoms of Mo?O bonds on the (010) basal plane resemble oxygen anion radicals and act as active sites for the adsorption and activation of benzyl alcohols by electrophilic attack. Such sites are indispensable for catalytic reactions since the blocking of these sites by electron acceptors, such as tetracyanoethylene (TCNE), can greatly decrease catalytic activity. This work represents a successful example of combining a heterogeneous catalysis study with nanomaterial synthesis. 相似文献
959.
Irradiation of the crystal of 1-perfluorophenyl-6-phenyl-1,3,5-hexatriene (1), the 1:1 cocrystal of 1,6-diphenyl-1,3,5-hexatriene (2) and 1,6-bis(perfluorophenyl)-1,3,5-hexatriene (3) (2/3), and crystal 3 gave a mixture of dimer, trimer and higher oligomers that was soluble in common organic solvents. The highest molecular weight was 5000-8000 (the degree of polymerization = 15-20). The order of reactivity was 1 > 2/3 ? 3. The reaction of 1 was relatively efficient compared to typical organic crystals. The conversion reached 100% after 3 h irradiation. In each case, the regio- and stereoselectivity in the photodimerization was high, whereas in the formation of trimer and higher oligomers, the selectivity was much lower. The main dimer was spectroscopically identified to be the face-to-face dimer formed by the [2 + 2] cycloaddition at the 1,2-position of the triene double bonds. The photoproducts from 1 and 2/3 were amorphous, as evidenced by powder X-ray diffraction and polarizing optical microscopy. This is probably due to the nonplanar and bulky structures of the cyclobutane products. The photodimerization and polymerization are considered to be non-topochemical reactions. 相似文献
960.
Zhangzhen He Jun-Ichi Yamaura Yutaka Ueda Wendan Cheng 《Journal of solid state chemistry》2009,182(9):2526-2529
Based on the phase diagram of CoO–V2O5 system, single crystals of Co2V2O7 are grown using V2O5 as self-flux at a slow cooling rate. The quality of grown crystals is analyzed by X-ray powder diffraction and electron probe microanalysis techniques. Magnetic properties are investigated by means of susceptibility, magnetization, and heat capacity measurements. Our experimental results suggest that Co2V2O7 is a three-dimensional antiferromagnet, in which two magnetic transitions may occur at low temperature and a spin-flop-like transition may occur at the applied field along the b-axis. By contrast to Ni2V2O7, it is suggested that similar and different magnetic properties may arise from their similar crystal structures and different magnetic ions, respectively. 相似文献