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Hye-Sun Jeon 《Tetrahedron letters》2004,45(38):7023-7026
Allylic sulfones undergo the conjugate addition to diethyl chloroisopropylidenemalonate, followed by intramolecular cyclopropanation. DBU-promoted ring opening and subsequent desulfonation reactions of the resulting adduct produce the conjugated polyene chains with the 1,4-dimethyl substitution. 相似文献
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Selenization of Fe2O3 with NaHSe led to Se/Fe3O4. The unexpected generation of Fe3O4 attributed to the reduction conditions of the reaction, and the resulted magnetic features of the material facilitated its separation in practical applications. Owning to the synergistic effect of Se with Fe, the material was especially active to catalyze the oxidative C=C scission using O2 as mild oxidant. The technique has been successfully applied in polyene degradation project, which is of profound practical values for the treatment of the polyene pigment pollution and may be applied in the food and pharmaceutical industry. 相似文献
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Xiang Ru Xianghua Zeng Zhimei Li David J. Evans Caixia Zhan Ying Tang Lianjie Wang Xiaoming Liu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(11):2410-2417
A complex pendant with two ethynyl groups, [Fe2(μ‐SCH2CCH)2(CO)6] ( 2 ), as a model of the diiron subunit of [FeFe]‐hydrogenase was polymerized and the {Fe2(CO)6} core was successfully incorporated into the polymer matrix. The polymer was characterized by a variety of spectroscopic techniques, TGA, FTIR, SEM, TEM, and NMR. The resultant polymer was immobilized via “click” chemistry using its terminal C?CH bond onto the surface of a gold electrode, which was premodified with azidothiol by self‐assembled monolayer (SAM). The assembled electrode showed electrochemical responses. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2410–2417, 2010 相似文献
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Neville J. McLeanAxel Gansmuller Maria ConcistreLynda J. Brown Malcom H. LevittRichard C.D. Brown 《Tetrahedron》2011,67(43):8404-8410
To enable solid-state NMR investigations of the rhodopsin chromophore and its photointermediates, a series of 11Z-retinal isotopomers have been synthesised containing pairs of adjacent 13C labels at C9/C10, C10/C11 or C11/C12, respectively. The C9 labelled carbon atom was introduced through the Heck reaction of a 13C-labelled Weinreb acrylamide derivative, and the label at the C12 position derived from a 13C-containing ethoxy Bestmann-Ohira reagent. The 13C labels at C10 and C11 were introduced through the reaction of β-ionone with labelled triethyl phosphonoacetate. 相似文献
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Lepidoptera, including about 150,000 species in the world, comprise the second largest insect group, and sex pheromones have been identified from virgin female moths of more than 600 species. The chemical structures are simple, but diverse, because species-specific pheromones play an important role in the reproductive isolation of each species. The pheromone content in each female is quite low, and gas chromatography coupled to mass spectrometry (GC-MS) is most frequently utilized to reveal the chemical structure. Almost all pheromone components are straight-chain compounds and are classified into two major groups [i.e. unsaturated C10-C18 fatty alcohols and their derivatives (Type I) and C17-C23 polyenyl hydrocarbons and their epoxides (Type II)]. In addition to the unbranched compounds, some species secrete methyl-branched compounds (e.g., 2-ketones). For the identification of these compounds, determining the positions of the double bond, the epoxy ring, and the methyl group is an important key step. Copious spectral information measured by electron-impact ionization (70 eV) has been accumulated for these compounds. This review therefore deals with their spectral characteristics, namely, diagnostic ions, to apply them to pheromone studies on new target insects. 相似文献
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Immanuel Plangger Dr. Tobias Pinkert Dr. Klaus Wurst Prof. Dr. Thomas Magauer 《Angewandte Chemie (International ed. in English)》2023,62(32):e202307719
We present a concise asymmetric total synthesis (5–8 steps) of nine sesquiterpenoid alkaloids featuring four different tetra-/pentacyclic scaffolds. To this end, a novel, bioinspired indole N-terminated cationic tricyclization has been developed, enabling the divergent synthesis of greenwayodendrines and polysin. Subtle variation of the C2-substituted indole cyclization precursor allowed switching between indole N- and C-termination. For the latter, a subsequent Witkop oxidation enabled conversion of the cyclopentene-fused indole into the eight-membered benzolactam to directly furnish the family of greenwaylactams. In addition, a diastereomeric C-termination product has been elaborated to provide access to polyveoline. 相似文献