<p>Systems based on copper(<span>ii</span>) bromide, <i>N,N,N′,N″,N″</i>-pentamethyldiethylenetriamine, and various reducing agents (ascorbic acid, glucose, sodium isoascorbate, and sodium dithionite) were proposed for the use to activate coupling processes of monobrominated polystyrene macroradicals <i>via</i> the radical trap-assisted atom transfer radical coupling method in the presence of nitrones of various structures. A distinctive feature of the proposed systems based on copper(<span>ii</span>) bromide is their higher stability compared to activators based on copper(<span>i</span>) bromide. The spin trap structure plays a predominant role in the coupling processes. Among the reducing agents studied for copper(<span>ii</span>) bromide, ascorbic acid is the most effective. The coupling process in the presence of copper(<span>ii</span>)-based catalytic systems using reducing agents and nitrones of various structures occurs with a high yield of the dimeric product (40–80%). The results of the study of the thermal destruction of the coupling products indicate the formation of high-molecular-weight alkoxyamines bearing the labile nitroxyl group.</p>