Role of B(C6F5)3 in catalyst activation, anion formation, and as C6F5 transfer agent

Bochmann, Manfred; Lancaster, Simon J.; Hannant, Mark D.; Rodriguez, Antonio; Schormann, Mark; Walker, Dennis A.; Woodman, Timothy J.

doi:10.1351/pac200375091183

Pure Appl. Chem., 2003, Vol. 75, No. 9, pp. 1183-1195

http://dx.doi.org/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 NH^2– 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.