[Dan]

Does anyone happen to know of a source for the pKa of phosphinic amides? I'm specifically after Ph₂PONHR (where R=H, alkyl [not Ar]), but anything close will do. The closest I've managed to get is some data for phosphoramidates, which I'd imagine are a less acidic, but numbers for anything closer would be handy.

[Honclbrif]

Sparc <http://archemcalc.com/sparc/> predicts about 18 for R = H and about 19 for R = CH₃. Don't know how much this will help you, but it might be better than nothing if you can't find some hard data.