Peralkylated Polyaminophosphazenes— Extremely Strong, Neutral Nitrogen Bases

Abstract

Probably the strongest uncharged nitrogen bases are readily accessible, unusually stable oligophosphazenes such as 1–3 (pKa(H2O)≤29–30). They are efficient dehydrohalogenating reagents for primary and secondary halides and exhibit low nucleophilicity. Their stability is revealed by, among other things, the fact that 1 only undergoes hydrolysis in D2O at 160°C and, even under these conditions, 2 and 3 remain unchanged for at least 20 h.