52957-98-9Relevant academic research and scientific papers
Copper-catalyzed oxidative heck reactions between alkyltrifluoroborates and vinyl arenes
Liwosz, Timothy W.,Chemler, Sherry R.
supporting information, p. 3034 - 3037 (2013/07/26)
We report herein that potassium alkyltrifluoroborates can be utilized in oxidative Heck-type reactions with vinyl arenes. The reaction is catalyzed by a Cu(OTf)2/1,10-phenanthroline with MnO2 as the stoichiometric oxidant. In addition to the alkyl Heck, amination, esterification, and dimerization reactions of alkyltrifluoroborates are demonstrated under analogous reaction conditions. Evidence for an alkyl radical intermediate is presented.
Polymerization of ethene with zirconocene catalysts: An experimental and quantum chemical study of the influence of para-substituent in benzyl in bis{η5-(1-benzyl)indenyl}zirconium dichlorides
Aitola, Erkki,Surakka, Marina,Repo, Timo,Linnolahti, Mikko,Lappalainen, Kristian,Kervinen, Kaisa,Klinga, Martti,Pakkanen, Tapani,Leskel?, Markku
, p. 773 - 783 (2007/10/03)
The meso- and rac-like isomers of bis{η5-(1-benzyl)indenyl} zirconium dichloride (5), bis{η5-(1-para-methoxybenzyl)indenyl} zirconium dichloride (6), bis{η5-(1-para-fluoro-benzyl)indenyl} zirconium dichloride (7) and bis{η5-(1-phenylethyl)indenyl} zirconium dichloride (8) were synthesized and isolated. Solid-state structures of meso- and rac-like 5 were determined by X-ray structure analysis. Polymerization properties of the methylaluminoxane (MAO) activated diastereomers of complexes 5-8 were studied in ethene polymerizations under different monomer concentrations. The rac-like isomer of 1-phenylethyl-substituted 8/MAO showed significantly higher activity than the 1-benzyl substituted analogs 5-7/MAO. In addition, rac-8/MAO behaves like a single center catalyst producing polyethene with narrow molar mass distribution (1.8-1.9), while diastereomers of 5-7/MAO produce polymers with molar mass distributions varying from 2.7 up to 10.3. The rac and meso-like isomers of 5-7/MAO have different response on the monomer concentration. Quantum chemical calculations suggest a strong interaction between the benzyl substituent and the electron deficient zirconium center. The phenyl metal coordination energies depend on the electronic properties of the para-substituent. In 8/MAO, due to the ethyl spacer, the coordination does not have a significant role and therefore much higher activity and single center polymerization behavior is observed.
