Benzyl-PEG2-azide

Benzyl-PEG2-azide is a polyethylene glycol–based azide linker designed for modular assembly of PROTACs, enabling efficient conjugation of targeting ligands through bioorthogonal click chemistry. Its PEG spacer promotes favorable solubility and conformational flexibility, supporting productive ternary complex formation in targeted protein degradation workflows. The sections below describe the linker’s structural features and practical reactivity considerations for constructing PROTAC intermediates.

Structure: The linker comprises an azide functional group attached to a short PEG chain terminated with a benzyl substituent. It contains ether linkages characteristic of PEG, providing polar, flexible connectivity. The azide moiety offers a distinct electrophile/partner site for cycloaddition, while the benzyl group contributes hydrophobic character.

Reactivity: Benzyl-PEG2-azide is well suited for copper-catalyzed azide–alkyne cycloaddition to form stable triazole linkages, a widely used strategy in PROTAC synthesis. Typical conditions employ a copper catalyst system, an appropriate reducing agent when required, and polar organic solvents compatible with azide stability. Reaction proceeds via formation of a copper–acetylide intermediate followed by cycloaddition to the azide, yielding the conjugated PROTAC scaffold.