Dual Scaffold Construction via Self-Assembled Chiral Ni(II)-Diamine Catalysts: Enantioselective Addition and Dieckmann Cyclization of Ynones with 3-Substituted Oxindoles

A novel chiral Ni(II)-diamine combinatorial catalyst has been developed for the asymmetric conjugate addition and cascade Dieckmann cyclization of ynones with 3-substituted oxindoles. This reaction offers rapid and convenient access to a wide array of enantiomerically enriched 3,3'-disubstituted oxindoles and synthetically valuable spirocyclopentenone oxindoles, employing a low catalyst loading under mild conditions. Control experiments reveal that precise chiral matching between the two diamine ligands is critical for achieving high chemo- and enantioselectivity.