Fig. 5: Details of DFT calculations of 2a, 2w for mechanism investigation.

a Computed Gibbs free energy changes of the reaction pathways in CHCl3. b DFT IRC pathway of the formation of 16 for the twice cyclo-expansion process from TS1. c DFT IRC pathway of the formation of 17 for the completed Nazarov cyclization and twice cyclo-expansion process from TS5-2.