38562-84-4Relevant academic research and scientific papers
Trimethylsilyl esters of phosphorus acids. II. Reactions of fluoro- and trifluoromethylphosphorus(V) oxides and sulfides with hexamethyldisiloxane and hexamethyldisilthiane and the synthesis of a novel phosphorane
Cavell,Leary,Tomlinson
, p. 2578 - 2583 (2008/10/08)
The reactions of the phosphoryl and thiophosphoryl compounds R2P(E)X (R = F, CF3; E = O, S; X = F, Cl, Br, CF3) with hexamethyldisiloxane and hexamethyldisilthiane ((Me3Si)2E′, E′ = O, S) have been investigated. The esters R2P-(E)E′SiMe3 or R2P(E′)ESiMe3 are generally formed, the yield obtained and ease of reaction being reduced when S replaces O in either starting reactant. Evidence indicates that the reactions proceed via intermediates having pentacoordinate phosphorus atoms, and one such phosphorane intermediate, (CF3)3P(OSiMe3)2, has been isolated and characterized. This new phosphorane, the first to be directly synthesized from a phosphine oxide, exhibits temperature-dependent 19F and 1H nmr spectral behavior which can be partially interpreted in terms of a fluxional trigonal-bipyramidal model. Nmr and new infrared data are also reported for (CF3)2P(O)Br.
