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41.
The new isocyanato carborane anion, [7-OCN-7-CB10H12]− was prepared by the reaction of 7-H3N-7-CB10H12 with triphosgene in the presence of triethylamine. The structure of this compound was established by 1H, 11B and 13C NMR as well as IR spectroscopy. The reactivigty of this compound with a series of organic amines was investigated. The resulting ureas were obtained in good to excellent yields. This approach is suitable for development of compounds for use in tumor selective Boron Neutron Capture Therapy (BNCT). 相似文献
42.
Reine-Marie Dia Rim Belaqziz Abderrahmane Romane Elisabet Duñach 《Tetrahedron letters》2010,51(16):2164-5160
A chemoenzymatic access to thiol compounds, including ethyl 3-thiobutanoate, 3-thio-p-menthene and 8-thio-p-menthan-2-one, three compounds of interest in flavour and fragrance chemistry presenting various fruity notes, is proposed. It involves an indium(III)-catalysed hydrothioacetylation of renewable precursors followed by an enzymatic solvolysis of the obtained thioesters by lipases in aqueous or organic solvents. 相似文献
43.
González-Mariño I Quintana JB Rodríguez I Schrader S Moeder M 《Analytica chimica acta》2011,684(1-2):50-57
A fully automated method for the determination of triclosan (TCS), its derivative methyl triclosan (MeTCS) and six parabens (esters of 4-hydroxybenzoic acid) including branched and linear isomers of propyl (i-PrP and n-PrP) and butyl paraben (i-BuP and n-BuP) in sewage water samples is presented. The procedure includes analytes enrichment by microextraction by packed sorbent (MEPS) coupled at-line to large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Under optimised conditions, compounds were extracted from 2 mL samples, adjusted at pH 3, using a C18 MEPS-sorbent. Adsorbed analytes were eluted directly into the Programmable Temperature Vaporizer (PTV) injector of the chromatograph with 2×25 μL of ethyl acetate. They were quantified using standard solutions in ultrapure water submitted to the same sample enrichment process as real sewage water samples. After signal normalisation using isotopic labelled species as internal surrogates, no differences were noticed among the extraction efficiency for sewage and ultrapure water; moreover, the proposed method reported lineal calibration curves from 0.1 to 10 ng mL(-1), relative standard deviations (%RSD) between 2 and 7.1% and limits of detection (LODs) varying from 0.001 to 0.015 ng mL(-1) in ultrapure water and from 0.02 to 0.59 ng mL(-1) in the most complex sample (raw wastewater). 相似文献
44.
Nonactivated trienes and aryltrienes were cyclized into polycyclic compounds in good to excellent yields under bismuth triflate catalysis in a biomimetic fashion. The reaction showed broad applicability and allowed for the formation of functionalized bicyclic to tetracyclic structures from simple precursors in one pot. For some specific substrates, the cyclization was followed by a methyl shift as encountered in terpenoid biosynthesis. 相似文献
45.
Croom B.P. Burden D. Jin H. Vonk N.H. Hoefnagels J.P.M. Smaniotto B. Hild F. Quintana E. Sun Q. Nie X. Li X. 《Experimental Mechanics》2021,61(2):395-410
Experimental Mechanics - The quality of Digital Volume Correlation (DVC) full-field displacement measurements depends directly on the characteristics of the X-ray Computed Tomography (XCT)... 相似文献
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47.
Francisco Gmez Robert Quintana Antxon Martez De Ilarduya Elisabet Rud Sebastin Muoz‐Guerra 《Journal of polymer science. Part A, Polymer chemistry》2005,43(1):92-100
A series of poly(butylene terephthalate) copolyesters containing 5‐tert‐butyl isophthalate units up to 50 mol %, as well as the homopolyester entirely made of these units, were prepared by polycondensation from a melt. The microstructure of the copolymers was determined by NMR to be random for the whole range of compositions. The effect exerted by the 5‐tert‐butyl isophthalate units on thermal, tensile, and gas transport properties was evaluated. Both the melting temperature (Tm) and crystallinity were found to decrease steadily with copolymerization, whereas the glass‐transition temperature (Tg) increased and the polyesters became more brittle. Permeability and solubility slightly increased with the content in substituted isophthalic units, whereas the diffusion coefficient remained practically constant. For the homopolyester poly(5‐tert‐butyl isophthalate), all these properties were found to deviate significantly from the general trend displayed by copolyesters, suggesting that a different structure in the solid state is likely adopted in this case. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 92–100, 2005 相似文献
48.
Sébastien KerverdoLouisette Lizzani-Cuvelier Elisabet Duñach 《Tetrahedron letters》2003,44(4):853-856
The cycloaddition reactions of various alkyl and aryl substituted α,β-unsaturated 1,3-oxathiolanes with styrene derivatives led to dihydrothiapyrans in the presence of TiCl4. Some mechanistic aspects of the cycloaddition are presented. 相似文献
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