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261.
Haruo Ogura Takanori Kobayashi Keiko Shimizu Kazumasa Kawabe Kazuyoshi Takeda 《Tetrahedron letters》1979,20(49):4745-4746
A convenient reagent for active ester synthesis --N,N′-disucinimidyl carbonate-- was prepared. This reagent was useful for the preparation of active esters and peptides in stead of dicyclohexylcarbodiimide. 相似文献
262.
Nishioka T Kitayama H Breedlove BK Shiomi K Kinoshita I Isobe K 《Inorganic chemistry》2004,43(18):5688-5697
Reaction of trans-[(MCp)(2)(mu-CH(2))(2)Cl(2)] (M = Rh, Ir; Cp = eta(5)-C(5)Me(5)) with Li(2)S(2) afforded the disulfido complexes [(MCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] which were easily oxidized by O(2) to give the oxygenated complexes [(MCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')]. Although [(RhCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] gave a complicated mixture when reacted with CH(2)Cl(2) or CHCl(3), [(IrCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] reacted with both CH(2)Cl(2) and CHCl(3) to give the dithioformato complex [(IrCp)(2)(mu-CH(2))(2)(mu-S(2)CH-S:S')]Cl and the cyclotetrasulfido complex [((IrCp)(2)(mu-CH(2))(2))(2)(mu-S(4)-S:S':S":S"')]Cl(2). The oxygenated complexes [(RhCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')] reacted with hydrocarbyl halides to afford bridging hydrocarbyl thiolato complexes accompanied by the generation of SO(2) gas. These complexes have been characterized by NMR spectroscopy, ESI-MS, and X-ray diffraction. 相似文献
263.
Cyclobutanones react with arylboronic acids in the presence of a catalytic amount of Rh(I) complex to afford butyrophenone derivatives through the addition of an arylrhodium(I) species to the carbonyl group, followed by ring-opening of the resulting rhodium(I) cyclobutanolate. [reaction: see text] 相似文献
264.
Tanaka R Yano T Nishioka T Nakajo K Breedlove BK Kimura K Kinoshita I Isobe K 《Chemical communications (Cambridge, England)》2002,(16):1686-1687
The novel thia-calix[n]pyridines (n = 3, 4, 6) coordinated to copper ions through nitrogen and sulfur atoms to give multinuclear complexes whose structures have been determined by X-ray crystallography and NMR spectra. 相似文献
265.
Hiraoka K Katsuragawa J Sugiyama T Kojima T Yamabe S 《Journal of the American Society for Mass Spectrometry》2001,12(2):144-149
Gas-phase clustering reactions of halide ions (X- = F-, Cl-, Br-, and I-) with ethylene (C2H4) and propylene (C3H6) were studied with a pulsed electron beam mass spectrometer. Bonding energies of all cluster ions were found to be less than 10 kcal/mol, i.e., no anion-initiated polymerization of C2H4 and C3H6 took place. For the cluster F-(C2H4)n, a small gap in the binding energy is observed between n = 4 and 5 suggesting that the first shell is completed with n = 4. For larger halide ions, the bond energies for the clusters X-(C2H4)n were found to be nearly n independent. For Cl-(C3H6)n a steep decrease in binding energies was observed between n = 2 and 3 and n = 3 and 4. The structure of the cluster ions was investigated by ab initio calculations. X-(C2H4)n complexes were calculated to have hydrogen-bond geometries regardless of the identity of the halide ions, and bidentate (chelate) type geometries of X-(C3H6)1 were found. 相似文献
266.
Takanori Yamazaki Tadao Seguchi 《Journal of polymer science. Part A, Polymer chemistry》2001,39(13):2151-2156
The effect of α‐methyl styrene dimer (AMSD), which is used as a scorch retarder, on the reaction mechanisms of the chemical crosslinking of polyethylene (PE) with dicumyl peroxide (DCP) at high temperatures was investigated using electron spin resonance. When AMSD was added to PE containing DCP, the AMSD radical was observed; however, the PE alkyl radical or allyl radical presence was not detected. At 145 °C, crosslinking was obstructed as a result of the reaction between AMSD and alkyl radicals. As the temperature increased, AMSD fragmented to form 2‐phenyl‐2‐propyl and double bonds in PE. This generation of double bonds, however, accelerated crosslinking at 180 °C and was more effective than when AMSD was not present. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2151–2156, 2001 相似文献
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