The copolymerization of propylene and 3-buten-1-of protected with alkylaluminum [trimethylaluminum (TMA) or triisobutylaluminum] was conducted with an isospecific zirconocene catalyst [rac-dimethylsilylbis(1-indenyl)zirconium dichloride], combined with methylaluminoxane as a cocatalyst, in the presence of additional TMA or H-2 as the chain-transfer reagent if necessary. The results indicated that endhydroxylated polypropylene was obtained in the presence of the chain-transfer reagents because of the formation of dormant species after the insertion of the 3-buten-1-ol-based monomer followed by chain-transfer reactions. The selectivity of the chain-transfer reactions was influenced by the alkylaluminum protecting the comonomer and the catalyst structure. (C) 2004 Wiley Periodicals, Inc.