1-(t-Boc-Aminooxy)-3-aminooxy-propane

This PROTAC linker building block, identified as 1-(t-Boc-Aminooxy)-3-aminooxy-propane, provides a protected aminooxy functionality alongside a second free aminooxy group, enabling modular assembly of targeted protein degraders. Its bifunctional design supports stepwise conjugation to ligands while maintaining compatibility with common PROTAC synthesis workflows. The protected group improves handling stability and selectivity during sequential coupling, and the aminooxy handles facilitate formation of stable oxime-based linkages. The detailed structural and reactivity considerations are provided below.

Structure: The molecule contains a propane backbone bearing two aminooxy substituents, with one aminooxy protected as a tert-butoxycarbonyl (t-Boc) carbamate derivative. It features N–O bonds typical of aminooxy chemistry, along with carbamate-related C–O and carbonyl functionalities that influence polarity and stability.

Reactivity: The free aminooxy group is well suited for oxime formation with aldehyde- or ketone-functionalized partners under mildly acidic conditions, while the t-Boc-protected aminooxy can be selectively deprotected prior to coupling. Typical approaches use acid-mediated Boc removal followed by controlled oxime ligation, often in polar organic solvents or mixed solvent systems compatible with PROTAC intermediates. Reaction selectivity is governed by sequential protection/deprotection and the electrophile choice for oxime chemistry.