Hydroxy-functionalized isotactic poly(1-butene) was synthesized using transition metal-catalyzed regioselective C-H borylation at the side chain of the commercial polyolefin and subsequent oxidation of the boronic ester functionality. Functionalization up to similar to 19 mol % of the termini of the ethyl side chain occurred without significant side reactions that could alter the polymer chain length. Esterification of the hydroxy group in the polymer with 2-bromoisobutyl bromide generated a side chain-functionalized polyolefin macroinitiator. Atom transfer radical polymerization of tert-butyl acrylate from the macroinitiator produced a high molecular-weight graft copolymer of the polyolefin, isotactic poly(1-butene)-graft-poly(tert-butyl acrylate) (PB-g-PtBA). Finally, the hydrolysis of the tert-butoxy ester group of PB-g-PtBA created an amphiphilic polyolefin, isotactic poly(l-butene)-graft-poly(acrylic acid), which contained a short carboxylic acid-functionalized polymer block at the side chain. (C) 2008 Wiley Periodicals, Inc.