Azido-PEG11-CH2COOH

Azido-PEG11-CH2COOH is a polyethylene glycol-based PROTAC linker bearing an azide handle and a terminal carboxylic acid. Its flexible PEG scaffold supports productive spatial presentation of ligands, while the azide enables bioorthogonal conjugation strategies commonly used in targeted protein degradation workflows. The carboxylate functionality further facilitates controlled coupling to complementary targeting moieties. The detailed structural and reactivity considerations are provided below.

Structure: The linker comprises a PEG chain providing conformational flexibility, terminated by an azide group and a methylene-linked carboxylic acid. It contains ether linkages characteristic of PEG, along with an organic azide and a terminal carboxyl group. These features support water compatibility and stable covalent attachment chemistry.

Reactivity: The azide group is suited for copper-catalyzed azide–alkyne cycloaddition or strain-promoted azide–alkene/alkyne conjugation, enabling modular assembly of PROTAC constructs. For carboxylic acid coupling, standard amide-forming approaches (e.g., activation with coupling reagents followed by reaction with an amine-bearing ligand) are typically used. Mild, anhydrous organic solvents or mixed aqueous conditions are commonly selected to preserve ligand integrity.