Activation and recyclization of a benzocyclobutenone derivative catalyzed by a chiral Rh(I) complex based on DFT investigations

The R- and S-activation and cyclization channels of an achiral benzocyclobutenone derivative to a pair of enantiomers with poly-fused rings were investigated systematically based on full optimization with the BP86 functional in gas phase and the M06 functional in tetrahydrofuran (THF). Both the BP86 and M06 methods show that the R-channel is energetically more favorable than the S-channel in gas phase and in THF. The rate-determining step for the R-channel is the C–C activation with a barrier of 17.2 kcal/mol in THF and 11.8 kcal/mol in gas phase, but for the S-channel, the rate-determining step is the pentatomic ring formation process with a barrier of 25.6 kcal/mol in THF and 22.3 kcal/mol in gas phase.