Fig. 4: Scope of Enantioselective [4 + 2] Spirocyclization Reactions^a.

^aReaction Conditions D: disubstituted benzocyclobutenone (0.1 mmol), dicarbonyl compound (0.12 mmol), [Rh(COD)]₂OTf (8 mol%), and L8 ligand (8 mol%) in THF (1 mL), 100 °C for 16 h. Isolated yield. [b] The N-allylisatin was used.