The radical polymerization of N,N-dimethylacrylamide (DMAAm) has been investigated in the presence of several alkali metal salts, including lithium bis(trifluoromethanesulfonyl)imide (LiNTf 2 ). The addition of an alkali metal salt led to a significant increase in the yield and molecular weight of the resulting polymer.NMR analysis of mixtures of DMAAm and LiNTf 2 suggested that DMAAm was being activated by the coordination of Li + to its CvO group. Electron spin resonance analysis of the DMAAm polymerization in the presence of LiNTf 2 suggested that the propagating radical was being stabilized by Li + through a single-electron lithium bond, because a signal for the propagating radical of the acrylamide derivatives was observed for the first time in solution when LiNTf 2 was added. Based on these results, we have proposed a mechanism for this polymerization, where the propagation steps occur between a lithium ionstabilized propagating radical and a lithium ion-activated incoming monomer. Furthermore, polymers with a wide range of stereoregularities, such as isotactic, syndiotactic and heterotactic systems, were successfully prepared using this method by carefully selecting the appropriate combination of solvent and alkali metal salt. † Electronic supplementary information (ESI) available: Dependence of polymer yield on the added amount of LiNTf 2 in toluene, additional 1 H NMR spectra of the main-chain methylene groups of the poly(DMAAm)s prepared in this study and changes in the chemical shifts of DMAAm in the presence of MNTf 2 . See View Article Online a [Monomer] 0 = 1.0 mol L −1 , [MAIB] 0 = 1.0 × 10 −2 mol L −1 , [alkali metal salts] 0 = 1.0 mol L −1 . b Determined from 1 H NMR signals. c Determined by SEC (PMMA standards). d Alkali metal salt was not completely dissolved. e Polymer precipitated during polymerization reaction. Polymer Chemistry PaperThis journal is