Azides

Azides

The PEG azide can potentially be reacted with an acetylene moiety (click reaction) or an aryl phosphine derivative, as part of several staudinger ligation options (see references). It can also be used as a precursor to the amine function in which it can be transformed via reduction with phosphines. The tremendous attraction to the azide functionality is its very low reactivity and high stability under most conditions. However, under very specific conditions, the azide is very reactive and highly selective. Furthermore, the addition of an azide group generates only low additional sterical demand.