mPEG11-amine

This mPEG11-amine linker is a polyethylene glycol–based amine building block designed to support PROTAC architectures by improving solubility and enabling modular conjugation to targeting ligands and E3 ligase binders. Its terminal primary amine provides a versatile handle for forming stable linker connections under widely used bioconjugation chemistries. The detailed structural and reactivity considerations for PROTAC construction are provided below.

Structure: The molecule comprises an mPEG chain terminating in a primary amine, featuring repeating ether linkages along the PEG backbone. The presence of an aliphatic amine enables formation of amide, urea, or carbamate derivatives. The ether-rich scaffold imparts hydrophilicity and flexible conformational behavior.

Reactivity: The terminal amine readily participates in coupling reactions such as amide bond formation with activated carboxylic acids, carbamate formation with activated carbonates, and urea formation with isocyanates or activated carbamoyl equivalents. Typical conditions use polar organic solvents or aqueous buffers at controlled pH, often with coupling reagents (for example, carbodiimides) and base. Reaction proceeds via nucleophilic acyl substitution or related activated intermediate pathways, and purification is commonly performed by standard chromatography or precipitation-based methods.