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91.
Aromatic C-H borylation using [IrCl(COD)]2 and 2,2′-bipyridinedicarboxylic acids was studied. 2,2′-Bipyridine-4,4′-dicarboxylic acid was complexed with [IrCl(COD)]2 in the presence of bis(pinacolato)diboron. The resulting iridium catalyst could be readily separated from the reaction mixture by simple filtration, and the recovered catalyst under a nitrogen atmosphere was still active and could be reused more than 10 times. 相似文献
92.
An improved method for proteomics studies, which includes the fluorogenic derivertization of protein mixtures with 7-chloro-4-(dimethylaminoethylaminosulfonyl)-2,1,3-benzoxadiazole (DAABD-Cl), followed by HPLC isolation, enzymatic digestion and identification of the derivatized proteins by HPLC-electrospray ionization (ESI)-MS/MS with the probability-based protein identification algorithm, identified 103 proteins in the soluble extract (10 microg protein) of Caenorhabditis elegans. 相似文献
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95.
Kakiuchi F Usui M Ueno S Chatani N Murai S 《Journal of the American Chemical Society》2004,126(9):2706-2707
The ruthenium-catalyzed reaction of aryl ethers having a carbonyl group at the ortho position to the ether group with organoboronates (R-B(OCH2CMe2CH2O), R = aryl, alkenyl, and alkyl) resulted in site-selective C-C bond formation. Among the transition metal complexes screened, the RuH2(CO)(PPh3)3 complex showed the highest activity. Several aromatic ketones having methoxy or phenoxy groups at the ortho position can also be used in this coupling reaction. A variety of arylboronates containing electron-donating (NMe2, OMe, methyl, and vinyl) and -withdrawing (F and CF3) groups reacted with methoxy ketones to give the corresponding coupling products in high yields. 相似文献
96.
Fumito Koizumi Yuichi Takahashi Rieko Tanaka Mayumi Yoshida Shun-ichi Ikeda 《Tetrahedron letters》2004,45(40):7419-7422
EI-1941-1 (1a) and EI-1941-2 (2a) accompanied by EI-1941-3 (3) have been isolated from culture broth of Farrowia sp. E-1941 as the inhibitors of interleukin-1β converting enzyme. The structures of 1a, 2a, and 3 were elucidated by the analysis of NMR and MS data, and finally the absolute stereochemistries of 1a and 2a were confirmed by optical rotation data, or X-ray crystallographic analysis of p-bromobenzoate, 2b, respectively. 相似文献
97.
Sudo S Tsubotani S Shimomura M Shinyashiki N Yagihara S 《The Journal of chemical physics》2004,121(15):7332-7340
Broadband dielectric measurements for 65 wt % ethylene glycol oligomer (EGO)-water mixtures with one to six repeat units of EGO molecules were performed in the frequency range of 10 microHz-10 GHz and the temperature range of 128-298 K. In the case of the water-EGO mixtures with one and two repeat units of the EGO molecule (small EGO), the shape of the dielectric loss peak of the primary process is asymmetrical about the logarithm of the frequency of maximum loss above the crossover temperature, T(C). The asymmetric process continues to the alpha process at a low frequency, and an additional beta process appears in the frequency range higher than that of the alpha process below T(C). In contrast, the water-EGO mixtures with three or more repeat units of the EGO molecule (large EGO) show a broad and symmetrical loss peak of the primary process above T(C). The symmetric process continues to the beta process, and an additional alpha process appears in the frequency range lower than that of the beta process below T(C). These different scenarios of the alpha-beta separation related to the shape of the loss peak above T(C) are a result of the difference in the cooperative motion of water and solute molecules. The solute and water molecules move cooperatively in the small EGO-water mixtures above T(C), and this cooperative motion leads to the asymmetric loss peak above T(C) and the alpha process below T(C). For the large EGO-water mixtures, the spatially restricted motion of water confined by solute molecules leads to the symmetric loss peak above T(C) and the beta process below T(C). 相似文献
98.
Iwaura R Ohnishi-Kameyama M Yoshida M Shimizu T 《Chemical communications (Cambridge, England)》2002,(22):2658-2659
Complementary base paired complex formation of a thymidine-appended bolaamphiphile with adenosine derivatives was able to be detected with high resolution and high sensitivity in aqueous solutions by electrospray ionization-Fourier-transform ion cyclotron resonance mass (ESI-FTICR MS) spectrometry. 相似文献
99.
A new pentacyclic cucurbitane glucoside and a new triterpene from the fruits of Gymnopetalum integrifolium 总被引:1,自引:0,他引:1
Sekine T Kurihara H Waku M Ikegami F Ruangrungsi N 《Chemical & pharmaceutical bulletin》2002,50(5):645-648
A new pentacyclic cucurbitane glucoside, named aoibaclyin (1) and a new triterpene (2) have been isolated from the EtOH extract of the fruits of Gymnopetalum integrifolium Kurz (Cucurbitaceae), together with three known compounds, bryoamaride (3), 25-O-acetylbryoamaride (4) and beta-sitosterol 3-O-beta-D-glucopyranoside (5). The structures of these compounds were elucidated by spectroscopic analyses. 相似文献
100.
Psilocin analogs having either a formyl group (9-12) or a bromine atom (13-18) at the 5- or 7-position have been prepared for the first time. Syntheses of 5- and 7-bromo derivatives of 4-hydroxy- (23, 24, 28) and 4-benzyloxyindole-3-carbaldehyde (19, 25, 29, 30), 4-benzyloxyindole-3-acetonitriles (20, 31), and 4-benzyloxy-N,N-dimethyltryptamine (32, 34, 35) have also been established. 相似文献