Facile and Efficient Enantioselective Hydroxyamination Reaction: Synthesis of 3‐Hydroxyamino‐2‐Oxindoles Using Nitrosoarenes

Abstract

Sc takes action: The highly enantioselective hydroxyamination reaction of N‐unprotected 2‐oxindoles with nitrosoarenes has been realized using the Sc(OTf)3/L1 complex. The catalyst system exhibited remarkably broad substrate scope and high efficiency. This transformation is the first example of a chiral ScIII/enolate activating a nitrosoarene, and can be conducted on a gram scale without loss in the ee values.

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

“…4 The development of efficient synthetic protocols leading to these products, particularly, those assembled with quaternary chiral carbon centers has been desired and extremely challenging. 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.…”

Enantioselective Nitroso Aldol Intramolecular Transesterification Cyclization Domino Reaction for Highly Effective Construction of Chiral Spirooxindoles

“…[4] In 2011, the Feng group reported a similar C-N addition reaction catalyzed by a chiral Lewis acid complex of Sc(OTf ) 3 /N,N-dioxide with excellent results. [5] In 2012, our group [6] and the Rios group [7] reported the same transformation in a satisfactory result in the presence of a bifunctional tertiary amine thiourea. Coquerel's group used the same strategy to effect a C-N nitroso aldol condensation reaction in the presence of a bifunctional tertiary amine thiourea.…”

Copper-Catalyzed Electrophilic Amination of sp2 and sp3 C−H Bonds

“…Early aminations took advantage of sp 2 nitrogen-containing compounds such as azides [65][66][67][68] and diazene dicarboxylates. [69][70][71][72][73][74][75][76][77][78][79][80][81][82][83] More recently, oxime esters [84][85][86][87][88][89] and nitroso compounds [90][91][92][93][94][95][96] have been used. However, for electrophilic amination reactions using sp 2 nitrogen-containing compounds, the formation of the corresponding amine requires reduction of the N−N or N−O bond.…”

“…Electrophilic aminating reagents used for the preparation of α-aminocarbonyl Figure 5. Electrophilic aminating reagents for amination of carbonyls compounds compounds include diazene dicarboxylates, [70][71][72][73][74][75][76][77][78][79][80][81][82][83] azides, 65 nitroso compounds, [90][91][92][93][94][95][96] oxaziridines, 97 O-diarylphosphinyl hydroxylamine, 135 N-halo amines, [98][99] and Oacylhydroxylamines. 56…”