Thalidomide-O-amido-CH2-PEG3-CH2-NH-Boc is primarily utilized in the development of PROTACs (Proteolysis Targeting Chimeras), which are innovative therapeutic agents designed to target and degrade specific proteins within cells. Its structure allows it to act as a linker, connecting a target protein-binding moiety to an E3 ubiquitin ligase-recruiting element, facilitating the ubiquitination and subsequent degradation of the target protein. This application is particularly significant in cancer research, where it is used to degrade oncogenic proteins that are otherwise difficult to target with traditional small-molecule inhibitors. Additionally, it finds use in chemical biology for studying protein function and interactions, as well as in drug discovery for identifying novel therapeutic targets. The Boc protecting group in its structure ensures stability during synthesis and can be selectively removed to enable further functionalization.