83947-80-2Relevant academic research and scientific papers
Synthesis, NMR studies, and catalytic activity of cationic and neutral olefin complexes of platinum(II) containing the η3-allyl ligand
Kurosawa, Hideo,Asada, Naonori
, p. 251 - 257 (2008/10/08)
Cationic PtII complexes containing terminal olefin ligands [Pt(η3-CH2CMeCH2)(PPh3)(CH 2=CHR)]ClO4 (2, R = CH2Ph, Et, Me) were prepared. Formation of the neutral analogues of 2, i.e., Pt(η3-CH2CMeCH2)Cl(CH2=CHR) (3, R = CH2Ph, Et, Me, C6H4Y-p; Y = NMe2, OMe, Me, H, Cl, NO2), from [Pt(η3-CH2CMeCH2)Cl]2 and the olefin in solution was confirmed by 1H and 13C NMR spectra. Comparison of the 13C NMR data and the stability trends in 2 and 3 indicated a much greater electrophilic activation of the olefin in 2 than in 3. All complexes of type 2 showed high catalytic activity in the double-bond migration of olefins under mild conditions, with catalysts recovered from the reaction mixture having been confirmed to almost completely retain the η3-methallyl and the PPh3 ligands. Deuterium-labeling experiments employing CH2=CDCH3 suggested a key intermediate to be a Pt-H species. In contrast, complexes of type 3 were totally inactive in catalyzing the same transformations. A possible relevance of the different nature of the metal-olefin bond in 2 and 3 to the different catalytic activity was discussed.
