Studies on heteroatom phosphorus–fluorine compounds
thesisposted on 07.08.2018, 14:28 authored by Michael J.C. Hewson
This thesis is concerned with phosphorus-fluorine compounds in which phosphorus has a coordination number of either four, five or six and with special emphasis on compounds substituted by heteroatom-containing organic groups. A new series of aryloxy-fluorophosphoranes of general formula RnPF2(OC6F5)3-n (where n = 0, 1, 2; R = Me, Ph, Me2N, Et2N) have been prepared from the reaction of the Lewis base silyl ether pentafluorophenyltrimethylsilyl ether with the Lewis acid fluorophosphoranes RnPF5-n (where n = 0, 1, 2; R = Me, Ph, Me2N, Et2N). In contrast to alkoxy-fluorophosphoranes, which are known to be thermally unstable, these new aryloxy-fluorophosphoranes are found to be stable. All the reactions discussed are characterised by multi-substitution contrasting to the substitution pattern for other heteroatom-fluorophosphoranes. An insight was obtained into the reaction of aryl trimethylsilyl ethers with fluorophosphoranes from the reaction of the fluorophosphoranes PhPF4 and Me2NPF4 with the silyl-ethers PhOSiMe3 and C6F5OSiMe3, respectively, in which it was ascertained that the reactions proceeded via trifluorophosphorane intermediates to give difluorophosphoranes as the only phosphorus–fluorine product. [Continues.]
Loughborough University of Technology (research grant).