CHO-Ph-CONH-PEG2-NHBoc

CHO-Ph-CONH-PEG2-NHBoc, is designed to connect a protein-binding ligand to an E3-recruiting moiety through a flexible polyethylene glycol spacer and a protected amine handle. Its combination of an amide-linked aromatic core and PEG-based conformational flexibility supports productive ternary complex formation while minimizing steric constraints. The protected functionality enables controlled stepwise assembly of PROTAC constructs; detailed structural and reactivity considerations are provided below.

Structure: The linker contains an aromatic phenyl group conjugated to an amide (–C(O)–NH–) and a short polyethylene glycol segment that provides hydrophilic, conformationally flexible spacing. A terminal Boc-protected amine offers a stable, masked nucleophile for later deprotection and coupling. Overall, it is an amide-rich, PEG-containing organic scaffold.

Reactivity: The Boc-protected amine is typically introduced or carried through synthesis under non-acidic conditions, then deprotected using acid to generate a free amine for subsequent amide or urea-forming couplings. For PROTAC assembly, standard peptide-coupling strategies can be applied to react the liberated amine with activated carboxylic acid derivatives (e.g., activated esters or acid chlorides) to form stable linkages. Mild bases and polar aprotic solvents are commonly used to preserve PEG and amide integrity.