A Cation-Captured Palladium(0) Anion: Synthesis, Structure, and Bonding of [PdBr(PPh3)2]− Ligated by an N-Heterocyclic Phosphenium Cation
Caputo, C., Brazeau, A., Hynes, Z., Price, J., Tuononen, H., & Jones, N. (2009). A Cation-Captured Palladium(0) Anion: Synthesis, Structure, and Bonding of [PdBr(PPh3)2]− Ligated by an N-Heterocyclic Phosphenium Cation. Organometallics, 28 (17), 5261-5265. doi:10.1021/om9006278
DisciplineEpäorgaaninen ja analyyttinen kemia
© 2009 American Chemical Society. This is a final draft version of an article whose final and definitive form has been published by ACS. Published in this repository with the kind permission of the publisher.
Unsaturated N-heterocyclic phosphenium cations (uNHP) stabilize the [Pd0(PR3)2X]− anion proposed over the past decade to be the crucial but elusive intermediate in palladium-catalyzed cross-coupling reactions (X = halide). Insertion of metal into the P−Br bond of the precursor mesityl-substituted bromophosphine gives the structurally characterized Pd(0)-phosphenium complex (uNHPMes)Pd(PPh3)2Br, which features a long Pd−Br bond (2.7240(9) Å) and the shortest known Pd−P bond (2.1166(17) Å). The reaction is proposed to proceed by an associative pathway involving a Pd-bromophosphine complex that undergoes P-to-Pd bromide transfer.