Divergent Cyclization Reactions of Morita–Baylis–Hillman Carbonates of 2‑Cyclohexenone and Isatylidene Malononitriles

Zwitterionic dienolates generated from Morita–Baylis–Hillman carbonates of cyclohexen-2-one and a phenolic tertiary amine catalyst underwent divergent cyclization reactions with isatylidene malononitriles. A new [4 + 2] stepwise cyclization process was disclosed to deliver complex bridged spirooxindoles after the initial δ′-regioselective Rauhut–Currier-type reaction with N-methyl electrophiles by the catalysis of β-isocupreidine, while spirooxindoles incorporating an aromatic chromene motif were generated with N-MOM acceptors in the presence of α-isocupreine through different domino transformations.