Amino-PEG6-alcohol

Amino-PEG6-alcohol is a polyethylene glycol (PEG)-based linker furnishing both a terminal primary amine and a hydroxyl group, enabling versatile conjugation strategies in PROTAC assembly. Its flexible, hydrophilic scaffold can help tune linker length, solubility, and the spatial presentation of E3-ligand and target-binding warhead moieties. The subsequent points describe its structural features and practical reactivity considerations for constructing PROTACs.

Structure: The linker comprises a PEG chain bearing terminal functional groups: a primary amino group and a primary alcohol. It contains repeating ether linkages that confer conformational flexibility and hydrophilicity, along with C–N and C–O bonds suitable for standard bioconjugation chemistries. Overall, it behaves as a polar, water-compatible spacer.

Reactivity: The terminal amine can be used for nucleophilic acyl substitution or coupling reactions to install activated carboxyl- or carbonate-bearing partners, while the alcohol can participate in esterification or ether-forming transformations after activation. Common approaches include amide-bond formation using activated carboxylic acid derivatives, and carbamate/ester formation via coupling reagents under mild, anhydrous conditions. Selection of solvent and base is typically guided by the electrophile’s activation chemistry and the need to preserve sensitive PROTAC-binding motifs.