“…The initial reports on SET-LRP involve activation, almost exclusively, by zerovalent copper or copper derivatives. However, in the last two years several groups have investigated alternative metallic catalytic sources, including silver (Ag), iron (Fe), − nickel (Ni), ytterbium (Yb), lanthanum (La), , gadolinium (Gd), magnesium (Mg), tin (Sn), and samarium (Sm) . For instance, Fe is highly attractive as it is inexpensive, nontoxic, abundant, environmentally benign, biocompatible, and easy to remove.…”