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251.
Masahito Ochiai Kenzo Sumi Yoshimitsu Nagao Eiichi Fujita 《Tetrahedron letters》1985,26(19):2351-2354
Vinyliodonium salts were synthesized from vinylsilanes by the reaction with iodosylbenzene and triethyloxonium tetrafluoroborate. The reaction occurs stereospecifically with retention of configuration. Vinyliodonium salts are highly effective as the activated species of vinyl iodides. Thus, a variety of substituted olefins including α-cyano and α-nitro olefins, vinyl sulfides, vinyl halides, and α,β-unsaturated esters, were prepared from under mild reaction conditions. 相似文献
252.
Dr. Weifan Wang Fiona Hanindita Yusei Tanaka Kotaro Ochiai Dr. Hiroyasu Sato Dr. Yongxin Li Prof. Dr. Takuma Yasuda Prof. Dr. Shingo Ito 《Angewandte Chemie (International ed. in English)》2023,62(8):e202218176
Sulfur-embedded polycyclic aromatic compounds have been used as building blocks for numerous organic semiconductors over the past few decades. While the success is based on thiophene-containing compounds, aromatic compounds that contain thiepine, a sulfur-containing seven-membered-ring arene, has been less well investigated. Here we report the synthesis and properties of π-extended pyrrole-fused heteropine compounds such as thiepine and oxepine. A π-extended pyrrole-fused thiepine exhibited a “pitched π-stacking” structure in the crystal, and exhibited a high charge carrier mobility of up to 1.0 cm2 V−1 s−1 in single-crystal field-effect transistors. 相似文献
253.
Bungo Ochiai Ikuyoshi Tomita Takeshi Endo 《Macromolecular rapid communications》2001,22(18):1485-1487
The coordination polymerization of 1‐ethynylcyclohexene was carried out using various rhodium catalysts. Polymerization catalyzed with [Rh(norbornadiene)Cl]2/triethylamine gave a well‐defined polyacetylene derivative bearing conjugated double bond moieties, whose UV‐vis absorption spectrum has its maximum at 380 nm and cut off at 500 nm. 相似文献
254.
255.
Isolation and Structure of Germylene‐Germyliumylidenes Stabilized by N‐Heterocyclic Imines 下载免费PDF全文
MSc. Tatsumi Ochiai Dr. Tibor Szilvási Dr. Daniel Franz Dr. Elisabeth Irran Prof. Dr. Shigeyoshi Inoue 《Angewandte Chemie (International ed. in English)》2016,55(38):11619-11624
The ditopic germanium complex FGe(NIPr)2Ge[BF4] ( 3 [BF4]; IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene) is prepared by the reaction of the amino(imino)germylene (Me3Si)2NGeNIPr ( 1 ) with BF3?OEt2. This monocation is converted into the germylene‐germyliumylidene 3 [BArF4] [ArF=3,5‐(CF3)2‐C6H3] by treatment with Na[BArF4]. The tetrafluoroborate salt 3 [BF4] reacts with 2 equivalents of Me3SiOTf to give the novel complex (OTf)(GeNIPr)2[OTf] ( 4 [OTf]), which affords 4 [BArF4] and 4 [Al(ORF)4] [RF=C(CF3)3] after anion exchange with Na[BArF4] or Ag[Al(ORF)4], respectively. The computational, as well as crystallographic study, reveals that 4 + has significant bis(germyliumylidene) dication character. 相似文献
256.
Dr. Koji Ochiai Dr. Sankar Kuppusamy Yusuke Yasui Tsubasa Okano Yasunobu Matsumoto Dr. Nishant R. Gupta Dr. Yohei Takahashi Prof. Dr. Takaaki Kubota Prof. Dr. Jun'ichi Kobayashi Prof. Dr. Yujiro Hayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3282-3286
Amphidinolide N, the structure of which has been recently revised, is a 26‐membered macrolide featuring allyl epoxide and tetrahydropyran moieties with 13 chiral centers. Due to its challenging structure and extraordinary potent cytotoxicity, amphidinolide N is a highly attractive target of total synthesis. During our total synthesis studies of the 7,10‐epimer of the proposed structure of amphidinolide N, we have synthesized the C1–C13 subunit enantio‐ and diastereoselectively. Key reactions include an l ‐proline catalyzed enantioselective intramolecular aldol reaction, Evans aldol reaction, Sharpless asymmetric epoxidation and Tamao–Fleming oxidation. To aid late‐stage manipulations, we also developed the 4‐(N‐benzyloxycarbonyl‐N‐methylamino)butyryl group as a novel ester protective group for the C9 alcohol. 相似文献
257.
[structure: see text] 4-tert-Butyl-1-cyclohexenyl(phenyl)(tetrafluoroborato)-lambda(3)-iodane forms a discrete supramolecular complex by the reaction with 18-crown-6. Solvolysis of the cyclohexenyl-lambda(3)-iodane in the presence of 18-crown-6 indicates that the complexation with 18-crown-6 tends to decrease the leaving group ability of hypervalent phenyl-lambda(3)-iodanyl groups. 相似文献
258.
Ochiai N Sasamoto K Daishima S Heiden AC Hoffmann A 《Journal of chromatography. A》2003,986(1):101-110
A method for the determination of stale-flavor carbonyl compounds including E-2-octenal, E-2-nonenal, E,Z-2,6-nonadienal and E,E-2,4-decadienal in beer was developed using stir bar sorptive extraction (SBSE) with in-situ derivatization followed by thermal desorption-GC-MS analysis. The derivatization conditions with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and the SBSE conditions--sampling mode, salt addition, sample volume, polydimethylsiloxane volume (sample/polydimethylsiloxane phase ratio) and extraction time--were examined. The method showed good linearity over the concentration range from 0.1 to 10 ng ml(-1) for all analytes and the correlation coefficients were higher than 0.9993. The limits of detection ranged from 0.021 to 0.032 ng ml(-1) for all analytes. The recoveries (98-101%) and precision (RSD 2.4-7.3%) of the method were examined by analyzing beer samples fortified at the 0.5-ng ml(-1) level. The method was successfully applied to low-level concentration samples. 相似文献
259.
Yasuyuki Takeda Itsumi Fujimaki Shinichi Ochiai Kazuhiko Aoki Yoshihiro Kudo Hiroaki Matsuda Yoshihisa Inoue Tadao Hakushi 《Journal of inclusion phenomena and macrocyclic chemistry》1992,13(2):129-138
Formation constants (K
ML) of 1:1 complexes of 15-(2,5-dioxahexyl)-15-methyl-16-crown-5 (L16C5) and 15,15-dimethyl-16-crown-5 (DM16C5) with alkali metal ions were determined in acetonitrile (AN) and propylene carbonate (PC) by conductometry at 25°C. Except for the case of Li+-and K+-16C5 complexes in PC, the selectivity sequences of L16C5 and DM16C5 are identical with those of the parent crown ether 16-crown-5 (16C5) regardless of the solvent (AN, PC, methanol) (Na1 > Li+ > K+ > Rb+ > Cs+), which show the size-fit correlation. The selectivities of L16C5 and DM16C5 for the alkali metal ions are governed not by the sidearms but by the cavity size. The stability of the crown ether complex is dependent not on the dielectric constant but largely on the donor number of the solvent. TheK
ML(M1
+)/K
ML(M2
+) ratio of L16C5 or 16C5 varies very much with the solvent in the cases of M1=Na, M2=K and M1=Na, M2=Li, but that of DM16C5 is almost constant regardless of the solvent. 相似文献
260.
Chikako Takahashi Satoshi Ochiai Makoto Suzuki 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(1):160-173
To measure the thermal emission from stratospheric minor species with high sensitivity, the Superconducting Submillimeter-wave Limb-Emission Sounder (SMILES) aboard the Japanese Experiment Module (JEM) of the International Space Station (ISS) carries 4 K cooled Superconductor–Insulator–Superconductor (SIS) mixers. The major feature of the SMILES is its high-sensitive measurement ability with low system noise temperature less than 700 K.As a part of the ground system for the SMILES, a level 2 data processing system (DPS-L2) has been developed. It retrieves the density distributions of the target species from calibrated spectra in near-real-time. The retrieval process consists of two parts: the forward model, which computes radiative transfer, and the inverse model, which deduces atmospheric states. Since the forward model must provide the most accurate basis for results and be implemented under limited computing resources, the forward model algorithm for an operational system has to be accurate and fast. Hence, the algorithm is improved (1) by designing accurate instrument functions such as the instrumental field of view (FOV), sideband rejection ratio of sideband separator, and spectral responses of acousto-optic spectrometer (AOS) and (2) by optimizing radiative transfer calculation.This paper presents the development of the DPS-L2 along with the details on its algorithm and the algorithm performance. The accuracy of this algorithm is better than 1%, and the processing time for single-scan spectra is less than 1 min with eight parallel processings using a 3.16-GHz Quad-Core Intel Xeon processor. Thus, this algorithm is suitable for the SMILES measurement. 相似文献