338392-82-8Relevant academic research and scientific papers
Carbon-carbon bond formation using yttrium(III) and the lanthanide elements
Fryzuk, Michael D.,Jafarpour, Laleh,Kerton, Francesca M.,Love, Jason B.,Patrick, Brian O.,Rettig, Steven J.
, p. 1387 - 1396 (2001)
The synthesis and characterization of a series of yttrium and lanthanide complexes that incorporate the macrocyclic bis(amidophosphine) ligand PhP(CH2SiMe2NSiMe2CH2)2PP h, [P2N2], are described. The starting materials, {[P2N2]M}2(μ-Cl)2, (M = Y, Sm, Ho, Yb, Lu), are prepared by the reaction of syn-Li2(dioxane)[P2N2] with MCl3(THF)3 in toluene. The reactivity of these complexes toward PhLi and other arylating agents is dependent on the size of the M3+ ion. M = Y and Ho undergo C-C bond formation reactions to give biphenyldiide compounds {[P2N2]M}2 {μ-η6:η6′ -(C6 H5)2} and {[P2N2]Y}2 {μ-η6:η6′ -(C6H4-p-Ph)2}. These have been structurally characterized and show the biphenyl dianion bridging two [P2N2]M fragments. These [P2N2]M fragments migrate over the bridging ligand's π-surface on the NMR time scale. M = Yb yields the paramagnetic monophenyl derivative [P2N2]Yb-(C6H5), where the Yb center is coordinatively unsaturated and resides in a distorted square-pyramidal environment. M = Lu results in a mixture of ate complexes of the formulation [P2N2]LuPh·LiCl , as evidenced by 7Li NMR. However, the biphenyl product {[P2N2]Lu}2- {μ-η6:η6′- (C6H5)2} can be synthesized via a reductive route. The presence of THF was found to be deleterious to the coupling reaction; in this case, the THF adduct [P2N2]Y(C6 H4-p-Me)-(THF) was isolated and structurally characterized. The mechanism for the C-C bond formation reaction is described based on the isolation of these yttrium and lanthanide complexes.
