Formation of Group 4 Metallocene-Enolate⋅B(C6F5)3 Adducts and Their Role as Initiators in the Rapid Polymerization of the Functionalized Olefin Methyl vinyl ketone
✍ Scribed by Wolf Spaether; Katrin Klaß; Gerhard Erker; Frank Zippel; Roland Fröhlich
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 180 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0947-6539
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✦ Synopsis
The Group 4 metallocene bis(enolate) complexes [Cp 2 M(-O-CMeCH 2 ) 2 ] (1) add one or two molar equivalents of the organometallic Lewis acid B(C 6 F 5 ) 3 to form the addition products
(3), respectively. Complexes 3 a (M Ti) and 3 b (M Zr) were characterized by X-ray diffraction. Complexes 2 undergo a thermally induced intramolecular aldol condensation type C ± C coupling. Mixtures of 1 and B(C 6 F 5 ) 3 , in ratios ranging from 1:1 to 1:4, give increasingly active catalyst systems for the polymerization of methyl vinyl ketone which proceeds by a group-transfer mechanism.