Organocatalyzed photoredox radical cyclopolymerization of methacrylate- and acrylamide-crotonate hybrid monomers†

Cascade bond-forming polymerizations have emerged as a powerful strategy for the synthesis of polymeric materials with advanced structures and properties. Among these, radical cyclopolymerization is one of the most extensively studied methodologies, although it still faces several challenges, including low cyclization rates, unwanted crosslinking, and lack of spatiotemporal control. Herein, we report the design and synthesis of methacrylate- and acrylamide-crotonate hybrid monomers, which undergo a visible light-driven, organocatalyzed photoredox ATRP-type cyclopolymerization. This approach eliminates crosslinking and proceeds through a sophisticated sequence of intramolecular cyclization and intermolecular propagation, yielding diverse homopolymers and block copolymers with cyclic repeating units. Additionally, factors influencing the control over polymer chain growth, such as light intensity and additives, are explored.