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

## TL;DR

A new organic catalyst enables better control and broader use of a polymerization method called O-ATRP, allowing the synthesis of complex polymers under milder conditions.

## Contribution

A super-reducing photoredox catalyst expands O-ATRP to challenging monomers and initiators, enabling controlled polymerization and grafting-from strategies.

## Key findings

- The super-reducing catalyst enables controlled polymerization of monomers like styrene and vinylcarbazole.
- The system allows air-tolerant and temporally regulated polymerizations.
- The method supports organocatalyzed grafting-from reactions on linear chains.

## 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.

A super‐reducing organic photocatalyst expands the scope of O‐ATRP to challenging initiators and monomers. The system enables controlled polymerizations with air tolerance, temporal regulation, and grafting‐from strategies, highlighting the transformative potential of super‐reducing PCs in reversible‐deactivation radical polymerization.