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991.
Nami Takahashi Yuya Nagase Genzoh Tanabe Osamu Muraoka Mitsuhiro Yoshimatsu 《Tetrahedron》2012,68(5):1566-1580
We have reported sodium alkoxide- or aryloxide-mediated cyclization of 4-oxahepta-1,6-diynes bearing the phenylsulfanyl group 1a–d. The reactions with diverse sodium alkoxides and aryloxide produced 4-alkoxymethyl- and 4-aryloxymethylfurans 2aa–2db in good to high yields. Although reactions with sodium benzenethiolate yielded 3,4-bis(phenylsulfanylmethyl)furans 5a–g, they readily desulfanylated in the presence of tributyltin hydride/AIBN to give the 3-methyl- and 3,4-dimethylfuran derivatives 6a–g. This method’s utility was demonstrated by the synthesis of tetrahydronaphthalenyl furan derivatives bearing alkoxy- and aryloxymethyl substituents. 相似文献
992.
993.
Fukuda Takahito Shinomura Masato Xia Peng Awatsuji Yasuhiro Nishio Kenzo Matoba Osamu 《Optical Review》2017,24(2):206-211
Optical Review - We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D)... 相似文献
994.
Dr. Aiichiro Nagaki Yuya Moriwaki Suguru Haraki Akira Kenmoku Naofumi Takabayashi Atsushi Hayashi Prof. Dr. Jun-Ichi Yoshida 《化学:亚洲杂志》2012,7(5):1061-1068
The use of Pd catalysts that contained a carbene ligand, such as PEPPSI-SIPr, speeded up the Murahashi coupling of ArLi with ArBr, by enabling its integration with the Br/Li exchange of ArBr with BuLi in flow. Space integration realized the rapid cross-coupling of two different ArBr substrates. However, the cross-coupling reaction with vinyl halides could not be achieved under similar conditions. Pd(OAc)2 was an effective catalyst, and the space integration of the Br/Li exchange of ArBr with BuLi and the Murahashi coupling with vinyl halides was successfully achieved. 相似文献
995.
996.
Takashi Noda Yuya Doi Yutaka Ohta Shin-ichi Takata Atsushi Takano Yushu Matsushita 《Journal of polymer science. Part A, Polymer chemistry》2020,58(15):2098-2107
A four-branched cage-shaped poly(ethylene oxide) (4C-PEO) was prepared by a coupling reaction at very dilute condition between two kinds of end-functional four-armed star-shaped PEOs having amino and N-hydroxysuccinimide groups on their four ends, followed by purification using α-cyclodextrin (α-CD). The raw coupling reaction product shows multiple peaks including various high molecular weight multimeric products in size-exclusion chromatography measurements, while the product after α-CD purification shows a single peak eluted slightly earlier than the precursor star PEOs. Moreover, the final product obtained has about twice higher molecular weight than the star precursors. These results suggest that the targeted 4C-PEO polymer was successfully isolated through the α-CD purification. Small-angle neutron scattering (SANS) measurements of the final product in dilute solution were conducted, and its chain conformation was evaluated from the scattering profile in comparison with linear and star polymers. It has been found that the cage-shaped sample exhibits a distinct peak at lower q-region in the Kratky plot, which is in strong contrast with the linear counterpart. This result must be originated from the characteristic cage-shaped architecture, that is, having branched and closed-loop configurations, and hence having higher segmental density than simple linear and star molecules. In fact, the present experimental result is consistent with the recent Monte Carlo simulation reported by Uehara and Deguchi. 相似文献
997.
We recently proposed a data mining approach for classifying companies into several groups using ellipsoidal surfaces. This problem can be formulated as a semi-definite programming problem, which can be solved within a practical amount of computation time by using a state-of-the-art semi-definite programming software. It turned out that this method performs better for this application than earlier methods based on linear and general quadratic surfaces. In this paper we will improve the performance of ellipsoidal separation by incorporating the idea of maximal margin hyperplane developed in the field of support vector machine. It will be demonstrated that the new method can very well simulate the rating of a leading rating company of Japan by using up to 18 financial attributes of 363 companies. This paper is expected to provide another evidence of the importance of ellipsoidal separation approach in credit risk analysis. 相似文献
998.
Manabe Yoshio Ishino Masato Fuji Hiroshi Kinoshita Junichi Fujioka Kana Yamamoto Kazuhisa 《Optical Review》2022,29(3):267-275
Optical Review - Laser-driven phosphor conversion (PC)-type white light sources are receiving a great deal of attention in next-generation high-intensity lighting and display technologies. Laser... 相似文献
999.
We consider the percolation problem in the high-temperature Ising model on the two-dimensional square lattice at or near critical external fields. We show that all scaling relations, except for a single hyperscaling relation, hold under the power law assumptions for the one-arm path and the four-arm paths. 相似文献
1000.
Synthesis of 2H‐Azirines by Iridium‐Catalyzed Decarboxylative Ring Contraction of Isoxazol‐5(4H)‐ones 下载免费PDF全文
Dr. Kazuhiro Okamoto Takuya Shimbayashi Masato Yoshida Atsushi Nanya Prof. Dr. Kouichi Ohe 《Angewandte Chemie (International ed. in English)》2016,55(25):7199-7202
A phosphine‐free iridium‐catalyzed reaction of isoxazol‐5(4H)‐ones (isoxazolones) has been developed, and affords 2H‐azirines through decarboxylation and ring contraction. This method provides an efficient and environmentally benign protocol which could replace the conventional approaches used to synthesize 2H‐azirines. 相似文献