Transition‐Metal Catalysts for Controlled Radical Polymerization: A First Update

This article, a follow-up on a recent review co-authored by one of us (Prog. Polym. Sci.2010, 35, 959–1021) discusses the most recent discoveries in the field of metal-catalyzed, reversible-deactivation radical polymerization. Remarkable examples include the use of non-toxic polyethylene glycols simultaneously as solvents and ligands for the iron-catalyzed ATRP, nickel complexes that promote polymerization via a dual radical/migratory-insertion pathway, and metalloenzymes as mediators of ARGET ATRP-type reactions. A thorough and critical overview of the mechanistic details as well as the experimental conditions used to carry out the polymerizations are given together with an overview of the future challenges.