Selective dimerisation of α-olefins using tungsten-based initiators
作者:Martin J. Hanton、Louisa Daubney、Tomas Lebl、Stacey Polas、David M. Smith、Alex Willemse
DOI:10.1039/c0dt00106f
日期:——
dimerisation, minimising the formation of undesired heavier oligomers. Notably, the selectivity within the dimer fraction is found to favour the formation of products with methyl branches. The selectivity towards individual olefin isomers has been determined and the system is found to also produce trace levels of dienes and alkanes. A kinetic study of the system reveals a second order dependence on substrate
α-烯烃1-戊烯的选择性二聚直至 1-壬烯据报道使用原位生成的催化剂六氯化钨, 苯胺, 三乙胺和烷基铝卤化物。试剂身份和反应化学计量以及活化剂,溶剂和溶剂的影响α-烯烃探讨底物的选择。发现该催化剂对二聚具有高度选择性,从而使不希望的较重的低聚物的形成减至最少。值得注意的是,发现二聚级分内的选择性有利于形成具有甲基支链的产物。已经确定了对各个烯烃异构体的选择性,并且发现该系统还产生痕量的二烯和烷烃。该系统的动力学研究揭示了对底物的二阶依赖性。将观察到的产物与金属环和Cossee型机理的预期产物进行比较,表明后者正在运行,这由C 2 H 4 / C 2 D 4的结果所证实。共二聚实验表明产品中存在完全的同位素加扰。因此,提出了一种机械方案来考虑所观察到的系统行为,包括二烯和烷烃的形成。
TANDEM TRANSFER HYDROGENATION AND OLIGOMERIZATION FOR HYDROCARBON PRODUCTION
申请人:California Institute of Technology
公开号:US20140200376A1
公开(公告)日:2014-07-17
The disclosure provides for hydrocarbon production by hydrogenation and oligomerizaton and, more particularly, to catalysis of alkanes and alkenes by a tandem transfer hydrogenation and oligomerization.
Scope and Mechanism of Homogeneous Tantalum/Iridium Tandem Catalytic Alkane/Alkene Upgrading using Sacrificial Hydrogen Acceptors
作者:David C. Leitch、Jay A. Labinger、John E. Bercaw
DOI:10.1021/om500231t
日期:2014.7.14
increases only modestly with temperature. In contrast, the rate of 1-hexene/n-heptane transfer hydrogenation catalyzed by t-Bu[PCP]IrH4 is inverse order in 1-hexene and increases substantially with temperature. Styrene has been investigated as an alternate sacrificial hydrogen acceptor. Styrene dimerization catalyzed by Cp*TaCl2(alkene) is considerably slower than 1-hexene dimerization. The conversion of styrene/heptane
Ligand exchange processes in zirconocene dichloride–trimethylaluminum bimetallic systems and their catalytic properties in reaction with alkenes
作者:Lyudmila V. Parfenova、Pavel V. Kovyazin、Vener Z. Gabdrakhmanov、Galina P. Istomina、Pavel V. Ivchenko、Ilya E. Nifant'ev、Leonard M. Khalilov、Usein M. Dzhemilev
DOI:10.1039/c8dt04156c
日期:——
probable intermediates in the zirconocene-catalyzed reactions of alkenes with AlMe3. The effect of solvent, the organoaluminum compound concentration and the addition of (ClAlMe2)2 on the activation parameters of the alkyl exchange in the trimethylaluminum dimer was studied as well. The constants and activation parameters of the methyl group exchange in the monoalkyl-substituted ansa-complexes L2ZrMeCl