767-59-9Relevant articles and documents
Indenyl zirconium dinitrogen chemistry: N2 coordination to an isolated zirconium sandwich and synthesis of side-on, end-on dinitrogen compounds
Pun, Doris,Lobkovsky, Emil,Chirik, Paul J.
, p. 6047 - 6054 (2008)
Exposure of the isolable zirconocene sandwich compounds, (η5-C5Me5)(η5-C 9H5-1-R1-3-R2)Zr (R1 = Me, iPr, tBu; R2 = Me) to one atmosphere of dinitrogen resulted in N2 coordination. X-ray diffraction and NMR spectroscopy establish that the resulting dimeric dinitrogen compounds contain an unusual μ2,η2-bridging indenyl ring and a weakly activated N2 ligand. N2 coordination from the isolable zirconium sandwich compounds is extremely sensitive to the number and size of the indenyl subsituents. Compounds bearing two [iPr] or three methyl substituents are stable as η9 sandwich compounds for weeks under dinitrogen likely due to the inability to dimerize through a two-atom N 2 bridge. Performing the reduction of (η5-C 5Me5)(η5-C9H5-1- R1-3-R2)ZrCl2 (R1 = iPr, tBu; R2 = Me; R1 = R2 = SiMe 3) under an N2 atmosphere produced a different outcome; rare examples of side-on, end-on zirconium dinitrogen compounds were isolated and in one case, crystallographically characterized. Protonolysis studies with weak Bronsted acids were used to evaluate the relative activation of the bridging dinitrogen ligands.
Catalysts that produce polyethylene with broad, bimodal molecular weight distribution
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, (2021/01/19)
The present disclosure relates to ansa-metallocene catalyst compounds that include (1) a first indenyl ligand substituted at the 3-position with a substituted or unsubstituted C4-C40 hydrocarbyl group, wherein the hydrocarbyl group is branched at the β-position, and (2) a second indenyl ligand substituted at its 3-position with a substituted or unsubstituted alkyl group or a β-branched alkyl group. Catalyst systems prepared with the catalyst compounds, polymerization methods using such catalyst systems, and polyolefins made using the polymerization methods are also described.
Carbocation catalysed ring closing aldehyde-olefin metathesis
Ni, Shengjun,Franzén, Johan
, p. 12982 - 12985 (2018/11/23)
A highly efficient aldehyde-olefin metathesis catalysed by the carbocation, 4-phenylphenyl-diphenylmethylium ion, has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.
NOVEL PRECATALYST SCAFFOLDS FOR CROSS-COUPLING REACTIONS, AND METHODS OF MAKING AND USING SAME
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Page/Page column 36, (2016/05/02)
The present invention provides novel transition-metal precatalysts that are useful in preparing active coupling catalysts. In certain embodiments, the precatalysts of the invention are air-stable and moisture-stable. The present invention further provides methods of making and using the precatalysts of the invention.
