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

A highly efficient Mukaiyama–Mannich reaction of N-Boc isatin ketimines and other active cyclic ketimines using difluoroenol silyl ethers catalyzed by Ph3PAuOTf

A Ph₃PAuOTf catalyzed highly efficient reaction of difluoroenoxysilanes and active ketimines is reported, which represents the first Au(i)-catalyzed Mukaiyama–Mannich reaction.

The origin for highly enantioselective induction of 1-naphthol to isatin-derived N-Boc ketimines catalyzed by quinine thiourea catalyst: an experimental and computational study

An enantioselective aza-Friedel–Crafts reaction of 1-naphthol with isatin derived N-Boc ketimines by cinchona based bifunctional thiourea as organo-catalyst is reported.

Tunable regioselective synthesis of pyrazolo[3,4-d]pyrimidine derivatives via aza-Wittig cyclization and dimroth-type rearrangement

A novel tunable regioselective synthesis of pyrazolo[3,4-d]pyrimidine derivatives via aza-Wittig/Ag(i) or base-promoted tandem reaction has been developed. This approach provides a concise way to construct this derivatives under mild condition.

The asymmetric synthesis of CF3-containing spiro[pyrrolidin-3,2′-oxindole] through the organocatalytic 1,3-dipolar cycloaddition reaction

A new strategy for the construction of optically active 5′-CF₃ spiro[pyrrolidin-3,2′-oxindole] was described by using CF₃CH₂NH₂ as a building block.

Stereoselective synthesis of 3-amino-2-oxindoles from isatin imines: new scaffolds for bioactivity evaluation

3-Substituted-3-aminooxindole motifs constitute the core structure of a number of natural products and drug candidates.

A highly diastereoselective Friedel–Crafts reaction of indoles with isatin-derived N-sulfinyl ketimines towards the efficient synthesis of chiral tetrasubstituted 3-indolyl-3-aminooxindoles

A Lewis acid promoted highly diastereoselective asymmetric Friedel–Crafts alkylation of indoles with isatin-derived N-tert-butanesulfinyl ketimines is described.

First example of quinine-squaramide catalyzed enantioselective addition of diphenyl phosphite to ketimines derived from isatins

A highly enantioselective addition of diphenyl phosphite to ketimines derived from isatins has been achieved using a bifunctional organocatalyst, quinine-derived squaramide catalyst. This method works efficiently with several ketimines to produce the corresponding 3-amino-2-oxoindolin-3-yl-phosphonates in excellent yields with high enantioselectivity (up to 98% ee).

Asymmetric Ugi 3CR on isatin-derived ketimine: synthesis of chiral 3,3-disubstituted 3-aminooxindole derivatives

An efficient Ugi three-component reaction of a preformed chiral ketimine derived from isatin with various isonitrile and acid components has been developed. The reactions proceeded smoothly and in a stereocontrolled manner with regard to the new center of the Ugi products due to the stereoinduction of the amine chiral residue. A wide variety of novel chiral 3,3-disubstituted 3-aminooxindoles were obtained, a selection of which were subjected to post-Ugi transformations, paving the way to application as peptidomimetics.

Bis(imidazolidine)pyridine-NiCl2 Catalyst for nitro-Mannich reaction of isatin-derived N-Boc ketimines: asymmetric synthesis of chiral 3-substituted 3-amino-2-oxindoles

An (S,S)-diphenyldiamine-derived bis(imidazolidine)pyridine (PyBidine)-NiCl2 complex catalyzed the nitro-Mannich reaction of isatin-derived N-Boc ketimines to construct a chiral quaternary aminocarbon center at the C3 position of oxindoles in yields of up to 99% with 95% ee.

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

The asymmetric catalytic aza-Morita-Baylis-Hillman (aza-MBH) reaction of isatin-derived ketimines with MVK has been established by using chiral amino and phosphino catalysts. The reaction resulted in biomedically important 3-substituted 3-amino-2-oxindoles in good yields (>80% for most cases) and with excellent enantioselectivity (90-99% ee). Twenty-eight cases assembled with chiral quaternary stereogenic centers have been examined under convenient systems.