Abstract The reaction of para-substituted phenyl isocyanates with amines and alcohols was studied by stopped-flow method. The Hammett correlation obtained showed that the sensitivity of the above mentioned reactions toward substituent effects is the same as that of analogous reactions of phenyl isothiocyanates (ρ~ 2). The rate constants of these reactions were found to be affected more by steric effects than by solvent effects. An one step ...