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Divalent ansa-Zirconocenes: Stereoselective Synthesis and High Activity for Propylene Polymerization

Authors :
Jorge Soto
Eugene Y.-X. Chen
Khalil A. Abboud
David D. Devore
Bernie Link
D. Patrick Green
David R. Wilson
Richard E. Campbell
Source :
Journal of the American Chemical Society. 126:42-43
Publication Year :
2003
Publisher :
American Chemical Society (ACS), 2003.

Abstract

The reduction of ZrCl4(PR3)2 with Li powder, in the presence of a stoichiometric amount of trans-1,4-diphenyl-1,3-butadiene, affords the Zr(II) diene complexes (1) in 90-93% yields. This reaction consists of a rate-limiting step for the formation of the chloride-bridged Zr(III) dimer (2) and a fast diene-driven disproportionation of 2 to 1 and ZrCl4(PR3)2 that re-enters the reduction cycle. The reaction of 1 with Li2{Me2Si(2-Me-4-Ph-Ind)2} in toluene produces quantitatively the desired racemic, divalent ansa-zirconocene (3) that is a highly active isospecific propylene polymerization catalyst upon activation with common activators.

Details

ISSN :
15205126 and 00027863
Volume :
126
Database :
OpenAIRE
Journal :
Journal of the American Chemical Society
Accession number :
edsair.doi.dedup.....58d1a87eb45d83ef5776c31d492a53f6
Full Text :
https://doi.org/10.1021/ja0381611