In the literature from 1998 is a protocol for a reaction involving diethyl methylphosphonate, 2.2 equivalents of LiHMDS, phenylsulfonylfluoride, to produce phenylsulfonylphosphonate within 90 minutes at room temperature (the authors do not discuss whether or not they took a time point in less than 90 minutes). The reagents are added successively at -78 °C, and the reaction is then allowed to warm to room temperature. I performed this reaction, and the crude product had the appropriate chemical shift of roughly 11 ppm (it was a test reaction, and I did not purify the product). I tried the analogous reaction with dimethylsulfamoyl fluoride on a small scale. After roughly 32 hours, I quenched an aliquot with HOAc, removed volatiles, and took a P-31 NMR. I saw a single peak near 31 ppm, which is within a ppm of one published value for diethyl methylphosphonate and about 20 ppm away from a typical sulfonyl phosphonate. I expected that the sulfamoyl fluoride would be slower, but I have little to judge on how much slower. The LiHMDS was old but was unopened.
The majority of the test reaction is still unquenched and I could simply let it stir for a week (nothing is likely to happen IMO), or I could try to reflux. The only other two things I can think of are to use a stronger base and to use the opposite synthetic disconnection. Thoughts?