The group transfer polymerization (GTP) of methyl acrylate (MA) was studied using pentafluorophenylbis(triflyl)methane (C6F5CHTf2) as the organocatalyst and 1-trimethylsiloxy-, 1-triethylsiloxy-, and 1-triisopropylsiloxy-1-methoxy-2-methyl-1-propene (MTSMe, MTSEt, and MTSiPr, respectively) as the initiators. The C6F5CHTf2-promoted GTP of MA using MTSiPr proceeded in a living nature to produce poly(methyl acrylate)s (PMAs) with controlled molecular weights and narrow molecular weight distributions, which allowed the synthesis of high-molecular-weight PMA with the number-average molecular weight (Mn(SEC)) of up to 108,000 and the polydispersity (Mw/Mn) of 1.07. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry measurement revealed that the obtained PMA possessed the chain end structure that originated from MTSiPr, showing that the C6F5CHTf2-promoted GTP of MA proceeded without any side reactions. In addition, the kinetic study and the postpolymerization experiment supported the living manner of the polymerization. Moreover, the block copolymerization of MA and n-butyl acrylate (nBA) smoothly proceeded to afford the well-defined PMA-block-poly(n-butyl acrylate) (PnBA). (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012