A new class of amphiphilic poly(a-oxazoline) block copolymers bearing triphenylphosphine moieties has been synthesized. In aqueous media, these polymers form functionalized micelles with transition metal binding sites located in the hydrophobic core, thereby forming a catalytic active microreactor. The triphenylphosphine moieties were selectively introduced into the hydrophobic block by polymer analogous Pd-catalyzed phosphorus-carbon coupling reaction. The corresponding polymer precursor was prepared by living cationic polymerization of 2-methyl-2-oxazoline forming the hydrophilic part and statistical copolymerization of 2-heptyl-2-oxazoline and omega-iodoarylheptyl-2-oxazoline for the functionalized hydrophobic segment. This route allows a direct control of the number of the ligand functions by the ratio of the two hydrophobic monomers.