O-(3,6,9,12-Tetraoxapentadec-14-yn-1-yl)hydroxylamine

This linker, O-(3,6,9,12-Tetraoxapentadec-14-yn-1-yl)hydroxylamine, is designed to provide a chemically addressable hydroxylamine handle for assembling PROTAC architectures. Its extended polyether-like segment supports productive spatial presentation of warheads, while the terminal alkyne enables orthogonal conjugation strategies. These features facilitate modular synthesis and optimization of targeted protein degradation constructs, and the detailed structure and reactivity considerations are provided below.

Structure: The molecule contains a hydroxylamine functional group connected through an ether-rich chain and a terminal alkyne. It features multiple oxygen atoms that confer polarity and conformational flexibility, alongside a carbon–carbon triple bond suitable for selective coupling chemistry. Overall, it behaves as a polar, linker-like scaffold for PROTAC assembly.

Reactivity: The hydroxylamine moiety can participate in nucleophilic substitution or condensation steps used to form stable linkages to electrophilic partners commonly employed in PROTAC synthesis. The terminal alkyne supports copper-catalyzed azide–alkyne cycloaddition or related alkyne functionalization under standard conditions. Typical approaches use inert atmosphere when needed, polar aprotic solvents for solubility, and catalysts such as copper(I) salts for click-type coupling.