Atom‐Transfer Radical Reactions under Mild Conditions with [{RuCl2(1,3,5‐C6H3iPr3)}2] and PCy3 as the Catalyst Precursors

Simply mixing the complex [{RuCl2(1,3,5-C6H3iPr3)}2] (1) with PCy3 is sufficient to generate a catalyst suitable for highly efficient atom-transfer radical addition and polymerization reactions at exceptionally low temperatures (see scheme). The steric congestion at the metal caused by the bulky ligands is thought to be essential for the reactivity of the catalyst.