Synthesis of N-Alkoxycarbonyl Ketimines Derived from Isatins and Their Application in Enantioselective Synthesis of 3-Aminooxindoles

Abstract

A simple and general method in the synthesis of N-alkoxycarbonyl ketimines derived from isatins has been described first. Generally, the enantioselective addition of 1,3-dicarbonyl compounds to this kind of ketimine affords chiral 3-amino oxindoles in high yield and excellent ee.

Asymmetric catalytic aza-Morita–Baylis–Hillman reaction for the synthesis of 3-substituted-3-aminooxindoles with chiral quaternary carbon centers

“…Recently, a significant advance has been achieved in the development of synthetic methodologies for these targets; These methods include organocatalytic and metal-catalyzed asymmetric α-amination, 5 chiral auxiliary-controlled diastereoselective synthesis of chiral 3-substituted 3-aminooxindoles 6 and enantioselective additions of isatin-derived ketimines. 7 Very recently, Wang and co-workers reported the asymmetric addition of 1,3-dicarbonyl compounds onto N -alkoxycarbonyl ketimines and asymmetric aza -Friedel-Craft reaction of indoles and pyrroles with N -Boc ketimines in the presence of chiral phosphoric acid catalysts; 8 the latter led to the formation of 3-aminooxindoles in good yields with excellent enantioselectivities. 9 …”

Catalytic Enantioselective Addition of Me2Zn to Isatins

“…Commercially available isatins were used as received. N-protected isatins 1 were prepared as described in the literature [42]. (2R,3S)-1-benzyl-3-hydroxy-3-methylindoline-2-carbonitrile (4a): TMSCN (37 µL, 0.294 mmol) was added dropwise on a solution of 3a (0.1 mmol) in CH 2 Cl 2 (2 mL) at room temperature under nitrogen.…”

Isatin derivatives in reactions with phosphorus(III–V) compounds

“…100 The range of imines accessible by this procedure was extended by Yan and coworkers, 101 who used various azaphosphoranes as starting materials (Scheme 41).…”