The present paper reports the ROMP of norbornene with [RuCl2(PPh3)(2)(L)(x)] where L represents the acyclic amines diethanolamine, triethanolamine, triethylamine, phenylamine, diphenylamine or sec-butylamine. Previous representative results with cyclic amines are also cited to observe of the behavior of cyclic and acyclic amines as ancillary ligands. Three productive types of ligands were observed as a function of their electronic nature and steric hindrance: ligands with high cone angle and strong sigma-donor character ((NH2Bu)-Bu-s, NEt3 and piperidine), ligands with high cone angle and low sigma-donor character (NH2Ph and NHPh2) and ligand with low cone angle and pi-acceptor character (4-HN2NC(O)-pyridine). Ligands with low cone angle and strong (T-donor character can restrict the catalytic activity of the metal complex (imidazole, pyridine, 4-H3C-pyridine and 4-H2N-pyridine). Thus, latent complexes can be designed using different amines as ancillary ligands. (c) 2006 Elsevier B.V. All rights reserved.