A new and flexible methodology catalyzed by bifunctional chiral thioureas has been developed to react β-nitro oxindoles 1 with aldehydes. This approach allowed us to achieve the first enantioselective organocatalytic synthesis of 3-spiro-α-alkylidene-γ-butyrolactone oxindoles 3. We examined the scope of the two starting materials and, varying the structure of the β-nitro oxindole 1, intriguing new products, derived from unexpected transformations, have been stereoselectively obtained. The aim of this study was to merge two potentially bioactive structural motifs: the spirooxindole substructure and the α-alkylidene-γ-butyrolactone moiety. A preliminary NMR study on the ability to reversibly trap 2-aminoethanethiol gave us promising results.
Cerisoli, L., Lombardo, M., Trombini, C., Quintavalla, A. (2016). The First Enantioselective Organocatalytic Synthesis of 3-Spiro-α-Alkylidene-γ-Butyrolactone Oxindoles. CHEMISTRY-A EUROPEAN JOURNAL, 22(11), 3865-3872 [10.1002/chem.201504157].
The First Enantioselective Organocatalytic Synthesis of 3-Spiro-α-Alkylidene-γ-Butyrolactone Oxindoles
CERISOLI, LUCIA;LOMBARDO, MARCO;TROMBINI, CLAUDIO;QUINTAVALLA, ARIANNA
2016
Abstract
A new and flexible methodology catalyzed by bifunctional chiral thioureas has been developed to react β-nitro oxindoles 1 with aldehydes. This approach allowed us to achieve the first enantioselective organocatalytic synthesis of 3-spiro-α-alkylidene-γ-butyrolactone oxindoles 3. We examined the scope of the two starting materials and, varying the structure of the β-nitro oxindole 1, intriguing new products, derived from unexpected transformations, have been stereoselectively obtained. The aim of this study was to merge two potentially bioactive structural motifs: the spirooxindole substructure and the α-alkylidene-γ-butyrolactone moiety. A preliminary NMR study on the ability to reversibly trap 2-aminoethanethiol gave us promising results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
