The catalytic system "PtBr2(0.3 mol%)/2P(OR)(3)/10nBu(4)PBr"(R = alkyl) discovered recently in our group, allows good to excellent catalytic activities for the intermolecular hydroamination of ethylene and higher alpha-olefins (1-hexene) with aniline type amines to give the expected N-ethyl- (1) and N,N-diethyl-anilines (2) along with 2-methyl-quinoline (3). A poisoning effect of alkyl and aromatic phosphines has been observed. This effect could be minimised using small amounts of molecular iodide which reacts with phosphorus ligands to form non-coordinating well-described ionic species. Interestingly, beneficial effects of added P(OR)(3) (R = alkyl) have been pointed out and further investigated. In this way, a new potential family of Arbuzov-type phosphorus-metal complexes has been suggested to be responsible for good catalytic activities found when using P(OR)(3) alkyl phosphites rather than PR3 (R = alkyl, aromatic) and P(OPh)(3) co-catalysts. [GRAPHICS] (C) 2013 Elsevier B.V. All rights reserved.