Details

Autor(en) / Beteiligte

• Chen, Eugene Y.-X
• Campbell, Richard E
• Devore, David D
• Green, D. Patrick
• Link, Bernie
• Soto, Jorge
• Wilson, David R
• Abboud, Khalil A

Titel

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

Ist Teil von

• Journal of the American Chemical Society, 2004-01, Vol.126 (1), p.42-43

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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.