N-(Boc-PEG1)-N-bis(PEG2-propargyl)

This PROTAC linker reagent, N-(Boc-PEG1)-N-bis(PEG2-propargyl), is designed to provide a bioconjugation-ready PEG-based scaffold that supports efficient attachment of targeting ligands through orthogonal chemistries. Its flexible, hydrophilic architecture can help modulate solubility and linker accessibility, which are important considerations in targeted protein degradation workflows. Detailed structural and synthetic guidance for assembling PROTAC constructs using this linker is provided below.

Structure: The molecule contains a Boc-protected amine linked to a short PEG segment and two PEG2-terminated propargyl arms. It features ether linkages characteristic of PEG, an amide/urethane-type connectivity associated with the protected nitrogen, and terminal alkyne functionalities for click-type conjugation.

Reactivity: The terminal propargyl groups enable copper-catalyzed azide–alkyne cycloaddition with azide-bearing partners, following standard PROTAC assembly strategies. Conjugation is typically performed under inert or controlled conditions using Cu(I)-generating systems, with polar solvents that dissolve PEG-rich components. The Boc group can be selectively removed under mild acid conditions to expose an amine for subsequent coupling, if required by the target-ligand design.