t-Boc-Aminooxy-PEG3-amine is a Boc-protected aminooxy molecule. The amine (NH2) group is reactive with carboxylic acids, activated NHS esters, carbonyls (ketone, aldehyde) etc. The Boc-aminooxy can be deprotected under mild acidic conditions and then reacts with an aldehyde to form a linkage.
