Azido-PEG9-alcohol

Azido-PEG9-alcohol is a polyethylene glycol (PEG)-based linker bearing a terminal azide and a hydroxyl group, designed to support modular assembly of PROTACs through bioorthogonal conjugation chemistry. Its flexible, hydrophilic PEG scaffold can help tune linker length, solubility, and conformational freedom between the ligand and the recruiting module. The terminal azide enables efficient click-type coupling, while the alcohol handle supports downstream functionalization.

Structure: The molecule comprises a PEG chain terminated by an azide group and a primary alcohol, providing a flexible, ether-rich backbone with polar functionality. It contains an azide substituent and hydroxyl group capable of hydrogen bonding, with ether linkages that confer conformational mobility and improved aqueous compatibility.

Reactivity: The azide functionality is well suited for strain-promoted or copper-catalyzed azide–alkyne cycloaddition, enabling attachment of a complementary alkyne-bearing PROTAC fragment under standard click conditions. The hydroxyl group can be used for derivatization to introduce further coupling handles. Typical approaches use inert atmospheres when needed, appropriate bases for activation steps, and solvents compatible with PEG solubility, following established PROTAC linker-conjugation protocols.