Some new water-soluble catalytic systems based on iron complexes of polyethylene oxide and block copolymers of ethylene oxide and propylene oxide functionalized by catechol or beta-cyclodextrin have been developed. These complexes were examined as catalysts for biomimetic hydroxylation of benzene and phenol by hydrogen peroxide. It is shown that the introduction of beta-cyclodextrin into the polyethylene oxide molecule is favourable for rate and selectivity of hydroxylation of aromatic compounds in a two-phase system.