Boc-Aminooxy-PEG4

Boc-Aminooxy-PEG4 is a protected aminooxy-functional polyethylene glycol linker designed for constructing PROTACs and related targeted protein degradation conjugates. Its PEG-based scaffold provides conformational flexibility and improved solubility, supporting efficient ternary complex formation and linker-mediated spatial tuning between ligand modules. The Boc-protection strategy enables controlled downstream functionalization, while the aminooxy handle supports chemoselective oxime ligation workflows.

Structure: The molecule contains a Boc-protected aminooxy group attached to a short, ether-rich PEG chain. It features multiple ether linkages, an aminooxy functional motif, and a carbamate protecting group. The resulting polarity and hydrogen-bonding capacity promote water compatibility and flexible conformational behavior.

Reactivity: For PROTAC assembly, Boc deprotection is typically performed under standard acid-promoted conditions to reveal the free aminooxy functionality. The aminooxy group then engages in oxime formation with aldehyde-bearing partners via nucleophilic addition followed by dehydration. Common approaches use mild aqueous or mixed solvent systems, with pH conditions chosen to favor imine/oxime formation while minimizing side reactions; no metal catalysts are generally required for oxime ligation.