Propenyl-PEG3-Propenyl

This Propenyl-PEG3-Propenyl linker is designed for assembling PROTAC constructs by providing a flexible, hydrophilic polyethylene glycol (PEG) spacer flanked by reactive propenyl handles. Its ether-rich backbone supports favorable solubility and conformational adaptability, which can help tune ternary complex formation and targeted protein degradation performance. Detailed structural and synthetic guidance is provided below.

Structure: The linker contains a PEG-based polyether chain that confers flexibility and strong hydrogen-bonding capacity through ether oxygen atoms. Terminal propenyl groups provide unsaturated carbon–carbon double bonds suitable for conjugation. Overall, it is an organic, ether-rich scaffold with polar, water-compatible characteristics.

Reactivity: The propenyl termini enable covalent attachment to complementary PROTAC warheads or handles via alkene-functionalization strategies commonly used in PROTAC linker chemistry. Suitable approaches include catalyst-mediated addition or related alkene coupling reactions under conditions that preserve PEG integrity. Selection of catalysts and solvents should follow the reactivity requirements of the partner functional group, with inert atmosphere and controlled temperature often used to minimize side reactions and maintain linker solubility.