A Theoretical Study on C-H Bond Dissociation Enthalpies of Three-membered and four-membered Heterocyclic Compounds

The 27 C-H bond dissociation enthalpies (BDEs) of heterocyclic compounds were evaluated by the composite high precision G4 and G3B3 methods. In addition, 60 heterocyclic compounds were evaluated by density functional theory method with 10 density functionals. Compared with the experimental values. Boese-Martin for Kinetics (BMK) method gave the best mean absolute deviation and root-mean-square error values of 7.9 and 10.2 kJ/mol, and the correlation coefficient R-2 is of 0.955. Therefore, we used BMK to study the C-H BDEs and the substituent effects of three-membered and four-membered heterocyclic compounds. The essence of C-H BDE change pattern was also analyzed by the natural bond orbital theory.