5698-48-6Relevant articles and documents
Effect of Alcohol Structure on the Kinetics of Etherification and Dehydration over Tungstated Zirconia
Rorrer, Julie,Pindi, Suresh,Toste, F. Dean,Bell, Alexis T.
, p. 3104 - 3111 (2018/09/06)
Linear and branched ether molecules have attracted recent interest as diesel additives and lubricants that can be produced from biomass-derived alcohols. In this study, tungstated zirconia was identified as a selective and green solid acid catalyst for the direct etherification of primary alcohols in the liquid phase, achieving ether selectivities of >94 % for C6–C12 linear alcohol coupling at 393 K. The length of linear primary alcohols (C6–C12) was shown to have a negligible effect on apparent activation energies for etherification and dehydration, demonstrating the possibility to produce both symmetrical and asymmetrical linear ethers. Reactions over a series of C6 alcohols with varying methyl branch positions indicated that substituted alcohols (2°, 3°) and alcohols with branches on the β-carbon readily undergo dehydration, but alcohols with branches at least three carbons away from the -OH group are highly selective to ether. A novel model compound, 4-hexyl-1dodecanol, was synthesized and tested to further demonstrate this structure–activity relationship. Trends in the effects of alcohol structure on selectivity were consistent with previously proposed mechanisms for etherification and dehydration, and help to define possible pathways to selectively form ethers from biomass-derived alcohols.
Structurally uniform 1-hexene, 1-octene, and 1-decene oligomers: Zirconocene/MAO-catalyzed preparation, characterization, and prospects of their use as low-viscosity low-temperature oil base stocks
Nifant'ev, Ilya E.,Vinogradov, Alexander A.,Vinogradov, Alexey A.,Sedov, Igor V.,Dorokhov, Viktor G.,Lyadov, Anton S.,Ivchenko, Pavel V.
, p. 40 - 50 (2017/09/25)
An original approach to α-olefin oligomerization as well as novel thermally stable zirconocene catalysts for use in such reactions has been elaborated. The method reported allows the achievement of fractions of lightweight α-olefin oligomers up to 90% yields without considerable formation of byproducts like internal alkenes, alkanes, and higher oligomers. Trimers, tetramers, and pentamers of 1-hexene, 1-octene, and 1-decene were isolated as individual compounds and were hydrogenated. Viscosity characteristics of the isolated saturated and unsaturated hydrocarbons have been studied at various temperatures. The isolated saturated oligomers of 1-octene and 1-decene outperform the traditional electrophilic oligomerization products in terms of viscosity indexes, pour points, and low-temperature viscosity.
Catalytic oligomerization of α-olefins in the presence of two-stage activated zirconocene catalyst based on 6,6-dimethylfulvene ‘dimer’
Nifant'ev, Ilya E.,Vinogradov, Alexey A.,Vinogradov, Alexander A.,Bezzubov, Stanislav I.,Ivchenko, Pavel V.
, p. 35 - 37 (2017/02/05)
Zirconocene obtained from 6,6-dimethylfulvene ‘dimer’, being activated subsequently with triisobutylaluminium and methylalumoxane, catalyzes transformation of α-olefins into a mixture of vinylidene oligomers with minimal losses to isomerization, which allows one to consider this catalyst perspective for the synthesis of branched hydrocarbons with uniform structure.
