tospeg4tbutyl ester

Tos-PEG4-t-butyl ester (Tos-PEG4-Boc) is a PROTAC linker characterized by its PEG composition. This compound plays a crucial role in the synthesis of a range of PROTACs, including BI-3663, a highly selective PTK2 FAK PROTAC. It employs cereblon ligands to target E3 ligases for the degradation of PTK2, exhibiting potent inhibitory activity with an IC50 of 18 nM[1].