The metal-catalyzed living radical polymerization of methyl methacrylate and styrene initiated with freshly prepared p-toluenesulfonyl iodide (TsI) and catalyzed with CuX/2,2'-bipyridine (bpy), where X is Cl, Br, or I, and various self-regulated copper-based catalytic systems, such as copper/bpy, copper(I) oxide/bpy, copper(I) sulfide/bpy, copper(I) selenide/bpy, and copper(I) telluride/bpy, is reported. The exchange of C-I into C-Br and C-Cl takes place when the living radical polymerization of methyl methacrylate is catalyzed by copper(l) bromide/bpy and copper(l) chloride/bpy, respectively. Therefore, the use of the TsI initiator facilitates the synthesis, starting from a single initiator, of poly(methyl methacrylate) containing C-I, C-Br, and C-Cl chain ends. (c) 2005 Wiley Periodicals, Inc.