Fig. 4: Investigation of the mechanism.
From: Catalytic enantioselective nitrone cycloadditions enabling collective syntheses of indole alkaloids
a The key transition states of 1,3-dipolar cycloaddition reactions. Gibbs free energy (in kcal/mol) obtained at the level of SMD(solvent)-B3LYP-D3/def2TZVP//B3LYP-D3/6-31G*. In accordance with experimental conditions, chloroform was utilized as the solvent for reactions involving 1a and 2a/2b with catalyst 4b. Dichloroethane was employed as the solvent for reactions of 6b and 2a with catalyst 4a. Additionally, toluene was the chosen solvent for reactions of 6b and 2b with catalyst 4a. b FMO diagram for the 1,3-dipolar cycloaddition reactions. HF/6-31G*//B3LYP-D3/6-31G*-computed orbital energies in eV are shown.
