Organocatalyzed Atom Transfer Radical Polymerization (O‐ATRP) Using a Super‐Reducing Photoredox Catalyst

Abstract The development of highly reducing photoredox catalysts (PCs) has brought forth new approaches to activating strong chemical bonds for small molecule and polymer synthesis. Organocatalyzed atom transfer radical polymerization (O‐ATRP) is a polymerization methodology that uses organic PCs for the synthesis of well‐defined polymers proceeding through a reversible‐deactivation mechanism. However, the reaction scope of O‐ATRP is confined to initiators and dormant polymer states that can be reduced by a PC. Herein, we report an O‐ATRP system using a super‐reducing PC to expand the capability of O‐ATRP to monomers (such as styrene (St) and vinylcarbazole (VCz)) and initiators (including aromatic halides and pseudo‐halides) that are challenging with most O‐ATRP systems. This system provides control over polymerization, air tolerance, and temporal regulation and enables the synthesis of polymer brushes via organocatalyzed grafting‐from reactions on linear chains. This strategy builds upon the transformative potential of super‐reducing PCs toward advancing the field of reversible‐deactivation radical polymerization.