The authors demonstrate a novel polymerization system of methacrylates which involves the reduction of alkyl 2-bromoisobutyrate by SmI2 in the presence of methacrylates and N,N-diethylpivalamide (DEPA) at -78 degrees C. Quantitative initiation efficiency was attainable, providing an excellent yield of poly(methyl methacrylate) [poly(MMA)] with high syndiotacticity (85%) and narrow molecular weight distribution(1.07). Ethyl, isopropyl, and benzyl methacrylates also gave polymers with low polydispersity (<1.12) by this method. The application of this polymerization system offered a new route for the mechanism switching of propagation centers in polarity. For example, the end-capping of poly(tetrahydrofuran) [poly(THF)] by sodium 2-bromoisobutyrate followed by the reduction of the terminal carbon-bromine bond in the presence of MMA and DEPA resulted in the formation of the block copolymer with low polydispersity without any contamination from the respective homopolymers.