Neutral versus cationic Group 3 metal alkyl catalysts: performance in intramolecular hydroamination/cyclisation.

The relative catalytic activity of neutral dialkyl versus cationic monoalkyl Group 3 metal catalysts in the intramolecular hydroamination/cyclisation of the 2,2-dimethyl-4-pentenylamine reference substrate was investigated. This was found to depend strongly on the nature of the monoanionic ancillary ligand. With a bidentate amidinate ligand, the neutral catalysts were quite effective, but their cationic derivatives showed a much lower activity.

Yttrium alkyl complexes with a sterically demanding benzamidinate ligand: synthesis, structure and catalytic ethene polymerisation.

The benzamidinate yttrium dialkyl complexes [PhC(NAr)2]Y(CH2SiMe3)2(THF)n (Ar = 2,6-diisopropylphenyl; n = 1, 2) were prepared; when activated with [PhNMe2H][B(C6F5)4], the species with n = 1 polymerises ethene to polyethene with a narrow polydispersity.