NH-bis(C2-PEG1-azide)

designated NH-bis(C2-PEG1-azide), provides a bifunctional polyethylene glycol-based scaffold bearing azide termini suitable for modular assembly of targeted protein degraders. Its PEG character supports solubility and conformational flexibility, while the azide handles enable efficient bioorthogonal conjugation strategies commonly used in PROTAC workflows. The subsequent points describe its structure and practical reactivity considerations for constructing PROTAC conjugates in research settings.

Structure: The linker contains a central amine unit connected to two short PEG segments terminated with azide groups. It features ether linkages characteristic of polyethylene glycol, along with C–N and N–H functionalities. Overall, it is a flexible, polar, water-compatible scaffold designed for stable linker incorporation.

Reactivity: The azide groups are designed for copper-catalyzed azide–alkyne cycloaddition or strain-promoted azide–alkene/alkyne conjugation, enabling selective formation of triazole or related linkages under mild conditions. Typical approaches use polar organic solvents or aqueous mixtures, with ligand-stabilized Cu(I) systems when employing CuAAC, while minimizing conditions that can reduce sensitive biomolecule partners.