Boc-aminooxy-PEG5-propargyl is a polyethylene glycol (PEG)-based linker commonly used in PROTAC synthesis[1], enabling the efficient formation of molecules designed to target specific proteins for degradation.

PROTACs, comprising two distinct ligands connected by a linker—one targeting an E3 ubiquitin ligase and the other targeting the protein of interest—utilize the intracellular ubiquitin-proteasome system to selectively degrade target proteins [1].