tert-Butyl 11-aminoundecanoate

tert-Butyl 11-aminoundecanoate, is a protected amino acid derivative designed to provide a flexible aliphatic spacer for assembling PROTAC architectures. Its features include a terminal protected amine and a chemically addressable carboxylate functionality, enabling modular coupling to ligands and subsequent deprotection strategies. Such linkers are widely used in targeted protein degradation workflows to tune spatial geometry, improve solubility, and support reliable synthetic elaboration of degraders, as detailed in the sections below.

Structure: An aliphatic, extended chain bearing a tert-butyl ester and a protected primary amine characterizes this linker. It contains a saturated hydrocarbon backbone, an ester linkage, and an amine functionality masked as a protected group, providing conformational flexibility and chemical stability under mild conditions.

Reactivity: For PROTAC construction, the tert-butyl ester is typically employed as a protected carboxyl group that can be selectively deprotected to reveal a carboxylic acid for amide bond formation. Coupling to amine-bearing ligands is commonly performed via carbodiimide-mediated ester-to-amide conversion or activated acid strategies. The protected amine can be retained during early coupling steps, then deprotected under standard conditions to enable subsequent conjugation. Solvent systems and base/activator choices should follow established peptide coupling protocols for comparable protected amino acid linkers.