Metal‐Free Organocatalyzed Atom Transfer Radical Polymerization: Synthesis, Applications, and Future Perspectives

Reversible deactivation radical polymerization (RDRP) is a class of powerful techniques capable of synthesizing polymers with a well‐defined structure, properties, and functionalities. Among the available RDRPs, ATRP is the most investigated. However, the necessity of a metal catalyst represents a drawback and limits its use for some applications. O‐ATRP emerged as an alternative to traditional ATRP that uses organic compounds that catalyze polymerization under light irradiation instead of metal. The friendly nature and the robustness of O‐ATRP allow its use in the synthesis of tailorable advanced materials with unique properties. In this review, the fundamental aspects of the reductive and oxidative quenching mechanism of O‐ATRP are provided, as well as insights into each component and its role in the reaction. Besides, the breakthrough recent studies that applied O‐ATRP for the synthesis of functional materials are presented, which illustrate the significant potential and impact of this technique across diverse fields. O‐ATRP has emerged as an important alternative for controllable polymerizations due to the use of photoredox organic catalysts instead of metals. The robustness and friendly‐nature of O‐ATRP endorse its use in the synthesis of tailorable materials with diverse properties. This review covers the fundamental aspects and progress of O‐ATRP, as well as developments in O‐ATRP‐based materials for several areas.