Pure Appl. Chem., 2003, Vol. 75, No. 9, pp. 1183-1195
doi:10.1351/pac200375091183
Role of B(C6F5)3 in catalyst activation, anion formation, and as C6F5 transfer agent*
Manfred Bochmann, Simon J. Lancaster, Mark D. Hannant, Antonio Rodriguez, Mark Schormann, Dennis A.Walker, and Timothy J.Woodman
Wolfson Materials and Catalysis Centre, School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, UK
Abstract:
The versatile reactivity of B(C6F5)3 in alkene polymerization reactions is summarized. Adduct formation with basic anions such as CN– and NH2– gives extremely weakly co- ordinating diborates, which are the basis of some of the most active polymerization catalysts known to date. By contrast, the reaction of B(C6F5)3 with zirconium half-sandwich complexes leads to extensive C6F5 transfer, including the surprising formation of borole-bridged triple decker complexes. Main group alkyls undergo such C6F5 exchange reactions very readily unless donor ligands are present. Borate salts of new three-coordinate zinc alkyl cations proved to be highly effective catalysts for the ring-opening polymerization of epoxides and lactones.
*Lecture presented at the XIth International Meeting on Boron Chemistry (IMEBORON XI), Moscow, Russia, 28 July - 2 August 2002. Other presentations are published in this issue, pp. 1157-1355.