m-PEG4-CH2-aldehyde

m-PEG4-CH2-aldehyde is a polyethylene glycol (PEG)-based aldehyde linker designed to enable efficient conjugation steps commonly used in PROTAC assembly workflows. Its PEG segment provides improved solubility and flexible spacing between functional modules, while the aldehyde handle supports selective formation of stable linkages to partner molecules. This product is therefore well suited for researchers seeking reproducible linker chemistry to build targeted protein degraders; detailed structural and reactivity considerations are provided below.

Structure: The linker contains a methoxy-terminated PEG chain bearing a primary aldehyde at the opposite end via a methylene spacer. It features ether linkages within the PEG backbone and a terminal carbonyl group characteristic of aldehydes, offering a polar, hydrogen-bonding-rich scaffold that supports aqueous compatibility and conformational flexibility.

Reactivity: The aldehyde group can undergo nucleophilic addition and reversible imine formation with primary amines, enabling subsequent reductive stabilization when appropriate reducing agents are used. For PROTAC construction, aldehyde–amine coupling is typically performed under mildly acidic to neutral conditions, often in polar organic or mixed aqueous solvents, with careful control of pH to balance imine formation and hydrolysis. No specialized catalysts are generally required beyond standard coupling/reduction reagents used for aldehyde conjugations.