It is interesting to study and compare the thermochemical parameters in the vinyl+O-2, phenyl+O-2 and dibenzofuranyl+O-2 chemical activation reaction systems as well as the corresponding peroxy radical and hydroperoxide adduct dissociations. The analogy in C-O and C-H bond energies, well depths, bond type environment and reaction paths in these three reaction systems suggest a corresponding similarity in the initial reaction kinetics of these unsaturated R+O-2 reactions. In this study we identify the similarities in thermochemistry, bond energies and reaction kinetics of paths. The similar structures and parameters suggest that calculations on the vinyl system can often serve as surrogate or model for reaction paths and kinetic barriers in the larger phenyl system and the large dibenzofuranyl system for which high-level calculations are difficult. Here the vinyl+O-2 and the phenyl+O-2 systems can be used as model for the dibenzofuranyl+O-2 system.