Nucleophilic substitution reactions of the tricyclic triphosphorus cage P(3)(CBu(t))(2): a novel rou
June 28th, 2008 | by admin |Nucleophilic substitution reactions of the tricyclic triphosphorus cage P(3)(CBu(t))(2): a novel route to polyphosphorus phosphenium complexes.
Substitution of Cl(-) in the tricyclic triphosphorus cage Cl(P(1))-P(3)(CBu(t))(2) by a range of both anionic and neutral nucleophiles has been investigated. With anionic nucleophiles, reaction with fluoride and hydride anion was shown to afford F(P(1))-P(3)(CBu(t)) and H(P(1))-P(3)(CBu(t))(2) respectively. Subsequent deprotonation of the latter results in the formation of the aromatic anion [1,2,4-P(3)(CBu(t))(2)](-). With neutral nucleophiles, addition of either PMe(3) or PEt(3) to Cl(P(1))-P(3)(CBu(t))(2) in the presence of TlOTf results in the formation of the phosphine-phosphenium complexes [(R(3)P(P(1))-P(3)(CBu(t))(2)][OTf] (R = Me or Et): the structure of the methyl-substituted compound was determined by a single crystal X-ray diffraction study. The phosphine ligand in these complexes is extremely labile and addition of I(2) to [(Me(3)P(P(1))-P(3)(CBu(t))(2)](+) results in the formation of I(P(1))-P(3)(CBu(t))(2).
Willans CE, Fish C, Green M, Kilby RJ, Lynam JM, Russell CA, Whitwood AC.
Department of Chemistry, University of York, Heslington, York, UKYO10 5DD. jml12@york.ac.uk.