This work is directed to the stereospecific living radical polymerization of acrylamides such as N,N-dimethylacrylamide and N-isopropylacrylamide with an iron complex and a Lewis acid. DMAM was polymerized with [FeCp(CO)(2)](2) in conjunction with an alkyl iodide [(CH3)(2)C(CO2Et)I] as an initiator in the presence of Y(OTf)(3) in toluene/methanol (1/1) at 60 degrees C to be converted almost quantitatively to the polymers with controlled molecular weights and high isotacticity (m > 80%), wherein the Fe-complex generates radical species from a covalent C-I bond of the dormant species and the Lewis acid controls the stereochemistry of the polymerization via coordination with the amide groups of the polymer terminal and the monomer. A series of Lewis acids were also used for the iron(I)-catalyzed DMAM polymerization, and Yb(OTf)(3) and Yb(NTf2)(3) proved effective in giving isotactic polymers without deteriorating the molecular weight control similar to Y(OTf)(3). Furthermore, a slight enhancement of isospecificity was observed for the iron-catalyzed system in comparison with the alpha,alpha-Azobisisobutyronitrile-initiated, when coupled with Y(OTf)(3). Stereoblock polymerization of DMAM via a one-pot reaction was also achieved by just adding the Y(OTf)3 methanol solution in the course of the polymerization to give atactic-b-isotactic poly(DMAM). A similar but slightly lower control in the molecular weight and tacticity was achieved in the polymerization of NIPAM with [FeCP(CO)(2)](2)/Y(OTf)(3), (c) 2006 Wiley Periodicals, Inc.