691-37-2Relevant articles and documents
Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
supporting information, p. 14806 - 14813 (2021/09/18)
We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
Pyridylamido hafnium complexes with a silylene bridge: Synthesis and olefin polymerization
Canich, Jo Ann M.,Hagadorn, John R.,Kulyabin, Pavel S.,Uborsky, Dmitry V.,Voskoboynikov, Alexander Z.
supporting information, p. 6693 - 6702 (2020/06/08)
The synthesis and characterisation of six novel Cs-symmetric pyridylamido hafnium complexes with a silylene bridge of the type [ArPy(R2Si)NAr′]HfAlk2 are reported. Four complexes have been structurally characterised using single crystal X-ray diffraction. Appreciable differences between the solid state structures of these complexes and the pyridylamido hafnium complexes with a CRR′ bridge were noted. Reactions with B(C6F5)3, [Ph3C][B(C6F5)4] and [HMe2NPh][B(C6F5)4] yielded active catalysts for the homopolymerisations of propene and 1-hexene and ethene/1-octene copolymerization. In spite of the Cs-symmetry of the precatalysts, isotactically enriched polypropylene and poly(1-hexene) were obtained. The fact that the mechanism of the catalyst activation includes the insertion of alkene into the Hf-CAr bond was demonstrated. It was found that the structures of Ar and the R2Si bridge influence the activity, molecular weight capability and 1-octene affinity of the catalysts.
CATALYSTS AND METHODS FOR DIMERIZING PROPYLENE
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Paragraph 0052-0057, (2020/02/06)
Catalysts for producing a branched aliphatic alkene are described. The catalyst can include a catalytic alkali metal or alkali metal composite on a mixed metal oxide support that includes a Column 1 metal and at least one of a Column 3 metal, a Column 4 metal or a lanthanide. The catalyst can have less than 50 wt.% of a metal carbonate. Methods of producing branched aliphatic alkenes by contacting the catalyst of the present invention with an aliphatic alpha olefin are also described.