The persistent radical effect in organic synthesis

The persistent radical effect (PRE) is a principle that explains the highly selective cross-coupling between a persistent and a transient radical when both species are formed at equal rates. In this paper, the concept of the PRE is briefly discussed. Applications of the PRE in different reactions such as Co-mediated radical addition and cyclization reactions, Kharasch reactions catalyzed by transition metals, the Barton reaction, and our nitroxide-mediated tin-free radical cyclizations are presented. Some future perspectives for the PRE in organic synthesis are also provided.