Aminooxy-PEG2-Aminooxy

This Aminooxy-PEG2-Aminooxy linker is designed for modular PROTAC synthesis, providing two reactive aminooxy termini for efficient formation of oxime-based conjugates with aldehyde- or ketone-bearing ligands. Its PEG-based spacer supports favorable solubility and conformational flexibility, which can improve linker–ligand presentation and targeted protein engagement. The detailed Structure and Reactivity parameters are provided below for experimental planning and synthesis optimization.

Structure: The linker contains a short polyethylene glycol spacer flanked by two aminooxy functional groups. These aminooxy groups enable formation of oxime linkages through condensation with carbonyl compounds. The PEG segment contributes ether-rich, flexible connectivity and generally enhances hydrophilicity and aqueous compatibility.

Reactivity: Aminooxy groups react with aldehydes or ketones under mild condensation conditions to form oxime products, typically driven by controlled pH and removal of water. Suitable approaches include sequential or orthogonal conjugation strategies, often using buffered aqueous/organic mixtures. Catalysts such as anilinium salts or mild acid/base conditions are commonly used to accelerate oxime formation while maintaining ligand integrity.