Catalytic Asymmetric Construction of Chiral Indoloazepine-Based Spirooxindoles via Formal 6+1 Cycloadditions

Key Points

• To develop a new chiral phosphoric acid-catalyzed reaction for creating chiral spirooxindoles.
• Utilized formal [6+1] cycloaddition of (2-aminobenzyl)indoles with isatins
• Applied chiral phosphoric acid as a catalyst
• Focused on optimizing yield and enantioselectivity
• Achieved up to 99% yield in synthesizing chiral spirooxindoles
• Obtained excellent enantioselectivities up to 97:3
• Demonstrated potent cytotoxic effects against HepG2 cancer cells