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71.
72.
Tsutomu Konno Tomoo Tanaka Tomotsugu Miyabe Atsunori Morigaki Takashi Ishihara 《Tetrahedron letters》2008,49(13):2106-2110
Treatment of fluoroalkylated electron-deficient olefins with various boronic acids in the presence of a catalytic amount of Rh(I) coordinated with (S)-BINAP in toluene/H2O at the reflux temperature for 3 h gave the corresponding conjugate addition products with high enantioselectivity in high yields. 相似文献
73.
A biosensor for peptide determination was constructed with trypsin or α-chymotrypsin immobilized on hydrogen ion-selective coated-wire electrode and its fundamental properties were investigated with two artificial peptides. The substrates could be determined in the range 0.1–40 mM with response times of 5–10 min. The effects of pH and concentration of buffer solution on the determination were investigated. 相似文献
74.
The pseudoplastic flow of suspensions, alumina or styrene-acrylamide copolymer particles in water or an aqueous solution of glycerin has been studied by the step-shear-rate method. The relation between the shear rate,D, and the shear stress,, in the step-shear-rate measurements, where the state of dispersion was considered to be constant, was expressed as = AD
1/2 +CD. The effective solid volume fraction,ø
F, andA were dependent on the shear rate and expressed byø
F =aD
b andA = D
. Combining the above relations, the steady flow curve was expressed by = D
1/2 + +
0 (1 – a D
b/0.74)–1.85
D, where
0 is the viscosity of the medium.With an increase in solid volume fraction and a decreases in the absolute value of the-potential, the flow behavior of the suspensions changed from Newtonian ( = = b = 0), slightly pseudoplastic ( = b = 0), pseudoplastic ( = 0) to a Bingham-like behavior.The change in viscosity of the medium had an effect on the change in the effective volume fraction. 相似文献
75.
76.
Sakakura A Hori M Fushimi M Ishihara K 《Journal of the American Chemical Society》2010,132(44):15550-15552
A chiral copper(II) complex of 3-(2-naphthyl)-l-alanine amide successfully catalyzes the enantioselective 1,3-dipolar cycloaddition reaction of nitrones with propioloylpyrazole and acryloylpyrazole derivatives. The asymmetric environment created by intramolecular π-cation interaction gives the corresponding adducts in high yields with excellent enantioselectivity. This is the first successful method for the catalytic enantioselective 1,3-dipolar cycloaddition of nitrones with acetylene derivatives. The 1,3-dipolar cycloadducts can be stereoselectively converted to β-lactams via reductive cleavage of the N-O bond using SmI(2). 相似文献
77.
A photoinduced spin-state change in the itinerant correlated electron system is studied. A photon introduced in the low-spin band insulator induces a bound state of the high-spin state and a photoexcited hole. This bound state brings a characteristic peak in the pump-probe optical absorption spectra which are completely different from the spectra in thermal-excited states. The present results well explain the recent experiments of the ultrafast optical spectroscopy in perovskite cobaltites. 相似文献
78.
A convenient synthesis of chiral 3,3′-disubstituted 1,1′-binaphthyl-2,2′-disulfonic acids (BINSA, 1) was developed. The key was directed ortho-lithiation of BINSA methyl ester 2 with n-BuLi and subsequent reaction with an electrophile. Electrophiles such as Br2, I2, Me3SiOTf, and i-PrOB(Pin) reacted smoothly with 3,3′-dilithiated BINSA methyl ester, and the corresponding 3,3′-dihalo-, 3,3′-bis(trimethylsilyl)-, and 3,3′-diboryl-BINSA derivatives were obtained in yields of 21–78%. This simple synthetic method is highly attractive since the ability to prepare 3,3′-disubstituted BINOLs in advance can be useful. 相似文献
79.
T Tatsuoka K Suzuki K Imao F Satoh T Ishihara I Hirotsu T Kihara M Hatta Y Horikawa K Sumoto 《Chemical & pharmaceutical bulletin》1992,40(9):2382-2386
A new series of 4-(1,4-benzoquinon-2-yl)-4-phenylbutanamides (2) were synthesized for evaluation of their pharmacological activities. All these compounds synthesized showed significant antilipidperoxidation (ALP) activities with brain homogenate in rats and some of them possessed a protective effect against hypobaric hypoxia in mice. Especially, a thiomorpholine derivative (2l, SUN-4757) showed a wide efficacy spectrum to a variety of experimental screening assays designed for cerebral protective agents, and it had a high LD50 value. 相似文献
80.