Intramolecular H-Bonds in an Organocatalyst Enabled an Asymmetric Michael/Alkylation Cascade Reaction to Construct Spirooxindoles Incorporating a Densely Substituted Cyclopropane Motif
A cascadeMichael addition/alkylationreaction between 3-chlorooxindoles and α-cyano chalcones catalyzed using a multifunctional quinine-derived aminoindanol-thiourea substance was investigated. A series of spirooxindoles incorporating a densely substituted cyclopropane motif were efficiently obtained with moderate to excellent diastereo- and enantioselectivity and further transformed to products with