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991.
P. E. Matkovskii G. P. Startseva V. Ya. Churkina L. P. Vasil’eva R. S. Yarullin 《Russian Chemical Bulletin》2008,57(3):674-678
Dec-1-ene oligomerization in the presence of an aluminum—1-dodecyl chloride system was studied. A mixture of low-molecular-weight
oligodecenes containing 25–40 wt.% dimers and 30–52 wt.% dec-1-ene trimers is formed at the molar ratios RCl/A1 = 0.5–1.5.
The oligomerization was assumed to occur under the action of cationic active sites, which are formed during the reaction of
1-chlorodedecane with aluminum. At temperatures of 120–130°C and molar ratios RCl/A1 = 0.5–1.5 metallic aluminum completely
dechlorinates 1-chlorododecane in a dec-1-ene medium. The character of the effect of highly dispersed Al and the RCl/A1 molar
rato on the fractional composition and chlorine content in oligodecenes was revealed. The latter are formed by an aluminum—tert-butyl chloride system used in the industrial oligomerization of dec-1-ene. A mechanism of Al dissolution by alkyl chlorides
with the simultaneous dechlorination of alkyl chloride and formation of cationic active sites in A1-RCl systems was proposed
to explain the results obtained.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 661–665, March, 2008. 相似文献
992.
本文介绍了射电偏振仪PПy—1的结构及其工作原理。该仪器是利用发射偏振的超高频无线电磁波透射复合材料构件,对接收到的信号进行分析来确定构件在工作状态下的应力应变值。本文还通过测试实例说明了仪器的使用及各种参数的确定方法。 相似文献
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Fañanás FJ Alvarez-Pérez M Rodríguez F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(20):5938-5944
Acetal derivatives are easily obtained from 1,2-difunctionalized compounds by a new reaction mediated by IPy2BF4 with a mechanism based on a 1,2-migration of aryl or alkyl groups. A new oxidative rearrangement reaction of olefins is also described. Moreover, when this metal-free protocol is applied to cyclic olefins, interesting ring-contraction reactions are observed. The new methodologies described here are a clean and efficient alternative to known strategies that make use of potentially toxic metallic complexes. 相似文献
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Reinscheid UM Zlatopolskiy BD Griesinger C Zeeck A de Meijere A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(10):2929-2945
Four new aza-analogues of hormaomycin 1, a secondary metabolite with interesting biological activities produced by Streptomyces griseoflavus, were synthesized and subjected to preliminary tests of their antibiotic activity to provide new insights into the structure-activity relationship studies of this class of compounds. The solution structures of hormaomycin 1 and its aza-analogue 2 a were determined by NMR spectroscopy. The data exhibited a reasonably rigid conformation for both molecules, stabilized by stacking interactions between the aromatic moieties attached to the ring and the side chain. According to NMR-spectral data the aza-analogue epi-2 a has a rather different conformation and indeed shows no antibacterial activity whatsoever. 相似文献
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