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91.
Dimethylphenylsilane was catalytically dehydrogenated and condensed in the presence of platinum complexes to give 1,1,2,2-tetramethyl-1,2-diphenyl-disilane. 相似文献
92.
RhCl(PMe3)3 (1) reacts with benzene under irradiation to give the oxidative addition product, Rh(C6H5)(H)Cl(PMe3)3 (2). The reaction is promoted under CO2 atmosphere. The structure of 2 was fully characterized by X-ray crystallography as well as NMR, IR, and elemental analysis. The adduct (2) is unstable in solution even at room temperature to regenerate benzene and 1. The thermolysis of 2 under a CO atmosphere produces benzaldehyde along with the reductive elimination product, benzene. On the other hand, the prolonged photoreaction of 1 with benzene under CO2 resulted in the activation of the C-H bond and CO2 to yield Rh(C6H5)(eta2-CO3)(PMe3)3 (3). 相似文献
93.
94.
Storer RI Takemoto T Jackson PS Brown DS Baxendale IR Ley SV 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(10):2529-2547
The total synthesis of the cytotoxic antitumour natural product epothilone C has provided a stage for the exploitation and further development of immobilized reagent methods. A stereoselective convergent synthetic strategy was applied, incorporating polymer-supported reagents, catalysts, scavengers and catch-and-release techniques to avoid frequent aqueous work-up and chromatographic purification. 相似文献
95.
Toshiyasu Sakakura Toshi-Aki Kobayashi Teruyuki Hayashi Yasujiro Kawabata Masato Tanaka Ikuei Ogata 《Journal of organometallic chemistry》1984,267(2):171-177
Phosphorus-carbon bonds of p-substituted triphenylphosphines were found to be cleaved under hydroformylation conditions in the presence of a rhodium, ruthenium, or cobalt carbonyl. Only p-isomers of the decomposition products (substituted benzaldehyde, benzyl alcohol, and/or biphenyl) were formed. The ability of metal carbonyls to cleave the PC bonds was Rh > Co > Ru. Tributylphosphine was stable under the conditions. The stability of metal carbonyl-phosphine catalyst systems was also examined and compared with the extent of PC bond cleavage. 相似文献
96.
Ken-ichi Fujita Takahito Muraki Hatsuhiko Hattori Toshiyasu Sakakura 《Tetrahedron letters》2006,47(28):4831-4834
A series of dendritic ligands with a 2,2′-bipyridine core was synthesized through the coupling of 4,4′-dihydroxy-2,2′-bipyridine with poly(arylether) dendron in fair yields. The corresponding copper(II) trifluoromethanesulfonate (triflate) dendrimers were applied as a Lewis acid catalyst to the Diels-Alder reaction. A positive dendritic effect on the chemical yields of adducts was observed. 相似文献
97.
Conformational features of palytoxin and acetylated palytoxin were investigated by detailed analyses of NOESY spectra. The conformational differences between palytoxin and acetylated palytoxin may account for the difference in the assembly state of palytoxin, which exists as an associated dimer, and the acetylated derivative, which exists as a monomer in aqueous solution. Two palytoxin units in the dimer may come in contact with each other at the hydrophobic region (C21-40) and the region around two conjugated double bonds (C60-84). The amino group of palytoxin is important for biological activities via Na/K ATPase, but it was not found to be involved in the contact faces of the two palytoxin units. This information should aid in revealing how palytoxin interacts with Na/K ATPase. 相似文献
98.
Mikuma T Ohyama T Terui N Yamamoto Y Hori H 《Chemical communications (Cambridge, England)》2003,(14):1708-1709
Haemin, iron(III)-protoporphyrin IX complex, and parallel-quadruplexed d(TTAGGG) have been shown to form a stable coordination complex which exhibits spectroscopic properties remarkably similar to those of haemoproteins. 相似文献
99.
Orihara Y Kamogawa M Takeuchi A Fukase H Nagao T 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2010,86(9):914-919
Following the electric current injection experiment carried out in 2009, a VLF-MT (Very Low Frequency Magnetotelluric) survey has been conducted in Kozu-shima Island to obtain further information on the subterranean electrical structure that might help understanding the results of our monitoring of geoelectric potentials. A number of VAN-type pre-seismic geoelectric potential anomalies were observed in 1997-2000, even showing a remarkable "Selectivity". However, similar pre-seismic anomalies were not observed during the Izu-Island volcano-seismic swarm 2000. All these observations would require extremely high degree of heterogeneity in the subterranean electrical structure of the volcanic island and its possible time changes. Several correlations between the results of this survey and the volcanic geology of the island and ground water distribution were found. Further investigation is needed for a complete explanation of the observed phenomena. 相似文献
100.
Keisuke Santo Kentaro Uchida Dr. Keisuke Fujimoto Dr. Toshiyasu Inuzuka Prof. Dr. Kazutaka Hirakawa Dr. Tetsuya Sengoku Prof. Dr. Masaki Takahashi 《European journal of organic chemistry》2023,26(9):e202201479
Newly designed fluorophore systems with feather-like structures were constructed by connecting bisanthracene building units via a concise reaction sequence of bromination, etherification, and desilylation. Spectroscopic characterizations revealed that all of the fluorophore systems achieved high light absorptivity and high emission efficiency by preventing closely spaced anthracene chromophores from mutual interactions to reduce concomitant energy loss by fluorescence quenching. The application of fluorophore systems for the preparation of light-harvesting dyad materials has successfully demonstrated their potential utility as versatile photofunctional tools. 相似文献