[Cesidio]

Does anyone have experience with diethyl iodo (or bromo) methylphosphonate?
I came across a prep discussing quaternization of triphenylphosphine with diphenyl chloromethylphosphonate at 175C for 4 hours (Tet Let 1968, 5731), however comparable reactions at 80C with diethyl iodomethylphosphonate don't work with tertiary amines to produce [R3N-CH2-P(O)(OEt)2]+[iodide]-.
There's also a prep (Chem&Bio 1998, 5, 307) reacting sodium thiophenolate with diethyl iodomethylphosphonate at RT to engender PhS-CH2-P(O)(OEt)2, however using the same above-mentioned tertiary amines (with similar 'effective pKa values' to thiophenolate) do not produce the quaternized [R3N-CH2-P(O)(OEt)2]+[iodide]-.
Any help would be appreciated.
Could the methylene proton in the I-CH2-P fragment actually be acidic?
Could there be something very different between the reactivity of diphenyl chloromethylphosphonate and diethyl iodomethylphosphonate?

[Babcock_Hall]

My limited experience with the alpha-haloalkylphosphonates is that they are not very reactive versus most nucleophiles.  The triflate derivatives of hydroxymethylenephosphonates, while not easy to make, are more easily displaced.  See Phillion and Andrew, Tet. Lett. 1986;27:1477–1480.  There is also a paper in Biochemistry, which cites this paper and uses a nitrogen nucleophile, but I cannot recall the citation offhand.  The latter paper used benzyl groups to form the diester, but ethyl and tert-butyl diesters with the triflate group have also been made.