Synthesis of μ-Phosphido Diiron Complexes Having a P−H Bond: Hydrophosphination of Phenylacetylene and Methyl Acrylate with the Cationic μ-Phosphido Diiron Complex
journal contributionposted on 14.03.2005, 00:00 by Junji Sugiura, Taeko Kakizawa, Hisako Hashimoto, Hiromi Tobita, Hiroshi Ogino
Thermal reaction of Cp2Fe2(CO)4 with PRH2 (R = Ph, Mes (mesityl)) in refluxing toluene afforded phosphido- and hydrido-bridged diiron complexes Cp2Fe2(CO)2(μ-H)(μ-PHR) (1a, R = Ph; 1b, R = Mes). Treatment of 1a with HOTf under a CO atmosphere produced the phosphido- and carbonyl-bridged cationic complex [Cp2Fe2(CO)2(μ-CO)(μ-PHPh)](OTf) (2) via hydride abstraction as hydrogen and CO coordination. Complex 2 reacted with phenylacetylene and methyl acrylate at room temperature to give [Cp2Fe2(CO)2(μ-CO)(μ-(E)-PPh(CHCHPh))](OTf) (3a) and [Cp2Fe2(CO)2(μ-CO)(μ-P(CH2CH2CO2Me)Ph)](OTf) (3b) in 78% and 65% yield, respectively, in the absence of any additive, as a result of hydrophosphination of the unsaturated carbon−carbon bond of the substrates with the P−H bond of 2.