Complexes of tris(pentafluorophenyl)boron with nitrogen-containing compounds: Synthesis, reactivity and metallocene activation

The strong Lewis acid tris(pentafluorophenyl)boron, B(C6F5)(3), reacts with several nitrogen-containing Lewis bases (nitriles, amines, imines, pyridines, etc.) and also with non-basic substrates (such as pyrroles and indoles) producing in both cases the B-N coordination adduct. With particular substrates (some tertiary amines, the imine 'Bu(Me)C=NBn, N-methyl-pyrrole and -indole,) the 1:1 borane/N-compound reaction produces zwitterions where a new B-C bond is generated. Some of the borane-N-compound adducts present Bronsted acidity and can be reacted with di-methyl group 4 complexes with generation of weakly associated ion pairs, which are active catalysts for the polymerization of olefins. (c) 2005 Elsevier B.V. All rights reserved.