Kinetics of PTC phenolysis of cyclophosphazenes has been measured in liquid-liquid and liquidsolid two-phase systems. The PTC reactions can be described in terms of a single mechanism without resorting to subdivision into extraction and phase-transfer constituents. The ratelimiting stage and topology is determined by the ratio of rate constants responsible for transfer of the reactant between the phases and the rate of chemical interaction. In other words, the topology of phase-transfer reaction and its rate-limiting stage is influenced by the same factors. This provides a possibility of purposeful changing the reaction zone and, hence, stereoselectivity by variation in lipophilicity-nucleophilicity ratio of the reactants.