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911.
Yamaguchi M Kumano T Masui D Yamagishi T 《Chemical communications (Cambridge, England)》2004,(7):798-799
The chloro(Me(2)SO)ruthenium(II) complexes with tris(2-pyridylmethyl)amine or its derivative catalyses the selective, stereospecific, and photoregulative alkane oxidation in the presence of 2,6-dichloropyridine N-oxide under visible light irradiation. 相似文献
912.
Matsumoto T Kamada Y Sugimoto T Tada T Noguchi S Nakazumi H Kawakami T Yamaguchi K Shiro M 《Inorganic chemistry》2003,42(26):8638-8645
The reaction of a new donor molecule having a planar but largely bent skeleton, bis(methylthio)tetrathiafulvalenothioquinone-1,3-dithiocarbonatodithiolemethide (1), with CuBr(2) in CH(3)CN/CS(2) afforded a black-colored crystal with a formula of 1(4).CuBr(4).2CuBr(3). In the crystal 1 molecules are one-dimensionally stacked to form half-cut pipelike columns, which are arranged to construct two different shapes of channels included by a one-dimensional array of CuBr(4)(2)(-) ions and a bibromide-bridged linear chain of CuBr(3)(-) ions with a square-pyramidal geometry at the Cu atom, [CuBr(3)(-)](n)(), respectively. The room-temperature electrical conductivity on the single crystal of 1(4).CuBr(4).2CuBr(3) was 2.0 x 10(-)(2) S cm(-)(1), and the temperature dependence of electrical conductivity was semiconducting with a large activation energy of 160 meV. The interactions between the neighboring Cu(II) d spins in the one-dimensional S = 1/2 spin systems due to CuBr(4)(2)(-) ions and CuBr(3)(-) ions in [CuBr(3)(-)](n)() were both antiferromagnetic, and the magnitudes were moderate (Weiss temperature, THETAV; = -18 K) in the former spin system and fairly large (coupling constant, J/k(B) = -120 K) in the latter spin system, which was in marked contrast to a moderate and ferromagnetic [CuBr(3)(-)](n)() chain in the cyclohexylammonium salt already known. 相似文献
913.
Yasuyuki Endo Chalermkiat Songkram Kentaro Yamaguchi 《Journal of organometallic chemistry》2005,690(11):2750-2756
In the crystal structure of 1,2-bis(o-carboranyl)benzene (2), the benzene ring is remarkably twisted out of planarity, owing to the steric bulkiness of two adjacent carboranyl groups. In the carboracycle (3), the two benzene rings are slantingly stacked owing to spatial control by the carborane cages. 相似文献
914.
A gas chromatographic method has been developed that permits the accurate and specific determination of the antianginal agent ANP-4364 in plasma. ANP-4364 is extracted with n-hexane containing ethyl chloroformate and, after a clean-up procedure, derivatized to the trichloroethyl carbamate, which is assayed on a gas chromatograph equipped with an electron-capture detector. Accurate determinations are possible over a concentration range from 1 to 50 ng/ml of ANP-4364 in plasma with a relative standard deviation of 7.5%. The minimum detectable concentration is 0.5 ng/ml. Plasma levels of ANP-4364 in dogs receiving oral (10 mg/kg) or intravenous (0.1 mg/kg) dosing have been determined. 相似文献
915.
The enthalpy of formation for LiMyMn2–yO4 (M=Co, Cr, Li, Mg, Ni) was measured by a Tian-Calvet type high temperature isothermal microcalorimeter. The standard enthalpy of formation for LiMn2O4 at 876 K was evaluated to be Hf0=–1404.2±6.4 kJ mol–1. The partial substitution of Co and Ni for Mn decreased the absolute Hf0 value, while that of Cr and Mg for Mn increased the absolute Hf0 value. In the case of the partial substitution of Li for Mn, no marked change in Hf0 could be observed.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
916.
Yoshio Hamashima Sadao Yamamoto Tadatoshi Kubota Katsuya Tokura Koji Ishikura Kyogi Minami Fumihiko Matsubara Masaaki Yamaguchi Ikuo Kikkawa Wataru Nagata 《Tetrahedron letters》1979,20(51):4947-4950
Synthesis of optically active 3′-nor-type 1-oxacephems from 6-APA was described. -Nitrobenzyl 7β-amino-3-chloro-7α-methoxy-1-oxa-3-cephem-4-carboxylate was also prepared. 相似文献
917.
Hayashi Y Shoji M Yamaguchi J Sato K Yamaguchi S Mukaiyama T Sakai K Asami Y Kakeya H Osada H 《Journal of the American Chemical Society》2002,124(41):12078-12079
The asymmetric total synthesis of (-)-azaspirene, an angiogenesis inhibitor, has been accomplished, establishing its absolute stereochemistry. The key steps are a MgBr2.OEt2-mediated, diastereoselective Mukaiyama aldol reaction, a NaH-promoted, intramolecular cyclization of an alkynylamide, and the aldol reaction of a ketone containing functionalized gamma-lactam moiety without protection of tert-alcohol and amide functionalities. 相似文献
918.
1-Ehtoxycarbonyl-1, 2-dihydroquinoline-2-phosphonates () were treated with n-butyllithium followed by alkyl halides to afford the corresponding 4-alkylated phosphonates () with complete regioselectivity in 67–97% yields. The phosphonates () were converted to 4-alkylquinolines () in ca. 50% yields by treatment with sodium iodide in HMPA or by alkaline hydrolysis in aqueous ethanol. 相似文献
919.
Heterogeneously catalyzed aerobic oxidative biaryl coupling of 2-naphthols and substituted phenols in water 总被引:1,自引:0,他引:1
Matsushita M Kamata K Yamaguchi K Mizuno N 《Journal of the American Chemical Society》2005,127(18):6632-6640
The oxidative coupling reaction can efficiently be promoted by supported ruthenium catalyst Ru(OH)x/Al2O3. A variety of 2-naphthols and substituted phenols can be converted to the corresponding biaryl compounds in moderate to excellent yields using molecular oxygen as a sole oxidant in water without any additives. The catalysis is truly heterogeneous in nature, and Ru(OH)x/Al2O3 can easily be recovered after the reaction. The catalyst can be recycled seven times with the maintenance of the catalytic performance, and the total turnover number reaches up to 160. The results of competitive coupling reactions suggest that the present oxidative biaryl coupling reaction proceeds via the homolytic coupling of two radical species and the Ru(OH)x/Al2O3 catalyst acts as an one-electron oxidant. Two radical species are coupled to give the corresponding biaryl product, and the one-electron reduced catalyst is reoxidized by molecular oxygen. The amounts of O(2) uptake and H(2)O formation were almost one-quarter and one-half the amount of substrate consumed, respectively, supporting the reaction mechanism. The kinetic data and kinetic isotope effect show that the reoxidation of the reduced catalyst is the rate-limiting step for the coupling reaction. 相似文献
920.
Yoshioka Y Kawai H Sato T Yamaguchi K Saito I 《Journal of the American Chemical Society》2003,125(7):1968-1974
The G-selectivity for Cu(I)-mediated one-electron oxidation of 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3' has been examined by ab initio molecular orbital calculations. It was confirmed that G(1) is selectively damaged by Cu(I) ion for both 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3', being good agreement with experimental results. The Cu(I)-mediated G(1)-selectivity is primarily due to the stability of the Cu(I)-coordinated complex, [-XG(1)G(2)G(3)-,-Cu(I)(H(2)O)(3)](+). The Cu(I) ion coordinates selectively to N7 of G(2) of 5'-G(1)G(2)G(3)-3' rather than N7 of G(1). The G(2)-selective coordination induces the G(1)-selective trap of a hole that is created by one-electron oxidation and migrates to GGG triplet. Therefore, the radical cation of G(1) is selectively created in both 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3', giving the G(1)-selective damage of 5'-G(1)G(2)G(3)-3'. 相似文献