Intramolecular H-Bonds in an Organocatalyst Enabled an Asymmetric Michael/Alkylation Cascade Reaction to Construct Spirooxindoles Incorporating a Densely Substituted Cyclopropane Motif
Na Wang, Xiao Yan, Zi-Tian Hu, Yi Feng, Lei Zhu, Zihang Chen, Huan Wang, Quan-Ling Wang, Qin Ouyang, Peng‐Fei Zheng
Abstract
A cascade Michael addition/alkylation reaction 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 versatile structural diversity. Density functional theory (DFT) calculations indicated that the tentative intramolecular hydrogen bonds in the chiral catalyst were crucial for the stereocontrol.
Topics & Concepts
ChemistryIntramolecular forceMichael reactionCyclopropaneAlkylationThioureaHydrogen bondCombinatorial chemistryCascade reactionOrganocatalysisCatalysisEnantioselective synthesisStereochemistryOrganic chemistryMoleculeRing (chemistry)Cyclopropane Reaction MechanismsAsymmetric Synthesis and CatalysisSynthesis and Catalytic Reactions