O-(2-(2-(2-(Prop-2-yn-1-yloxy)ethoxy)ethoxy)ethyl)hydroxylamine

O-(2-(2-(2-(Prop-2-yn-1-yloxy)ethoxy)ethoxy)ethyl)hydroxylamine, is designed to provide a flexible, polyether-based spacer that supports efficient positioning between a ligand and the degradation-targeting module. Its terminal hydroxylamine functionality enables chemoselective conjugation strategies commonly used in PROTAC assembly, while the propargyl ether motif supports orthogonal click-type functionalization.

Structure: The linker contains an O-alkylated polyether chain with multiple ether linkages, terminating in a hydroxylamine group and a propargyl ether (prop-2-yn-1-yloxy) handle. It features an aliphatic backbone with heteroatom-rich connectivity that promotes solvation and conformational flexibility.

Reactivity: The hydroxylamine can be used for nucleophilic coupling to electrophilic partners under mild, aqueous-compatible conditions, leveraging hydroxylamine’s ability to form stable linkages with activated carbonyl or leaving-group-containing intermediates. The terminal alkyne/propargyl ether is suitable for copper-catalyzed azide–alkyne cycloaddition or related orthogonal alkyne chemistries. Typical setups employ inert atmosphere, appropriate base or buffer, and solvents compatible with both coupling and click steps.