1606996-82-0Relevant articles and documents
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
Arai, Takayoshi,Matsumura, Eri,Masu, Hyuma
, p. 2768 - 2771 (2014)
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.
Isatin N-protected ketimines with nitromethane catalyzed by chiral binol linked monomeric macrocyclic Cu(II)–salen complex
Menapara, Tusharkumar,Tak, Raj kumar,Saravanan,Kureshy, Rukhsana I.,Khan, Noor-ul H.,Ganguly,Si, Mrinal Kanti
, p. 7000 - 7008 (2018)
Chiral Cu-1B generated in situ was used as an efficient catalyst for the synthesis of β-nitroamines in high yield (88%) with excellent enantioselectivity (ee up to 99%) at RT in absence of co-catalyst via asymmetric aza-Henry reaction of various isatin derived N-Boc ketimines with nitromethane. This catalytic system did not work well with other nitroalkanes under the above optimized reaction conditions. To examine this catalytic behaviour, quantum chemical DFT calculations were performed with the nucleophiles (CH2NO2 ? and CH3CHNO2 ?) for the conversion of 1a to 2a using macrocyclic Cu-1B complex. The DFT calculated results have shown that the reaction with CH2NO2 ? is more favourable than the corresponding CH3CHNO2 ?. The calculated activation barriers suggest that the reaction with CH2NO2 ? is ～8.0 kcal/mol energetically favoured than CH3CHNO2 ?. This catalytic protocol was further used to obtain chiral β-diamines (a building block for pharmaceuticals) at gram scale. In order to elucidate the reaction mechanism of asymmetric aza Henry reaction kinetic experiments were performed with different concentrations of the catalyst Cu-1B, nitromethane and 1g as the representative substrate. The reaction of isatin N-Boc ketimine was first order with respect to the concentration of the catalyst and the nitromethane but did not depend on the initial concentration of the substrate. A possible mechanism for the aza Henry reaction was proposed.
Organocatalytic enantioselective aza-Henry reaction of ketimines derived from isatins: Access to optically active 3-amino-2-oxindoles
Kumar, Akshay,Kaur, Jasneet,Chimni, Swapandeep Singh,Jassal, Amanpreet Kaur
, p. 24816 - 24819 (2014)
An organocatalytic asymmetric aza-Henry reaction of ketimines derived from isatins with nitroalkanes has been achieved using Cinchona alkaloid organocatalysts. This method works efficiently with several ketimines to produce a good (up to 82%) yield of the corresponding 3-substituted 3-amino-2-oxindoles with a good (up to 89%) enantiomeric excess.
Asymmetric phase-transfer catalysts bearing multiple hydrogen-bonding donors: Synthesis and application in nitro-Mannich reaction of isatin-derived N-Boc ketimines
Liu, Yuxin,Liu, Yu,Wang, Jingdong,Wei, Zhonglin,Cao, Jungang,Liang, Dapeng,Lin, Yingjie,Duan, Haifeng
, p. 2400 - 2403 (2017)
A series of bifunctional asymmetric phase-transfer catalysts bearing multiple hydrogen-bonding donors derived from cinchona alkaloids are synthesized, and successfully applied to asymmetric nitro-Mannich of isatin-derived N-Boc ketimines. The products 3-substituted 3-amino-oxindoles were constructed in excellent yields (96–99%) and good enantioselectivities (up to 95% ee).
Quinine-Based Trifunctional Organocatalyst for Tandem Aza-Henry Reaction-Cyclization: Asymmetric Synthesis of Spiroxindole-Pyrrolidine/Piperidines
Hajra, Saumen,Jana, Bibekananda
, p. 4778 - 4781 (2017/09/23)
A quinine-derived trifunctional sulphonamide catalyst has been developed for the effective asymmetric organocatalytic tandem aza-Henry reaction-cyclization of isatin-derived ketimines and nitroalkane-mesylates for the synthesis of spiro-pyrrolidine/piperidine-oxindoles. Demethylation of traditional bifunctional catalyst to incorporate an additional hydrogen bonding C6′-OH group plays the key role toward remarkable enantioselectivity.
Chiral bifunctional guanidine-catalyzed enantioselective aza-henry reaction of isatin-derived ketimines
Fang, Bing,Liu, Xiaohua,Zhao, Jiannan,Tang, Yu,Lin, Lili,Feng, Xiaoming
supporting information, p. 3332 - 3338 (2015/03/30)
An efficient asymmetric aza-Henry reaction of isatin-derived ketimines has been achieved by using a chiral guanidine-amide organocatalyst. A series of 3-substituted 3-amino-2-oxindoles was obtained with excellent results (up to 99% yield, 94% ee). Other functionalized derivatives were also conveniently transformed. This metal-free system was convenient, practical, and insensitive to air and moisture. On the basis of the crystal structure of the catalyst and NMR spectra analysis, a bifunctional catalytic model was suggested to explain the origin of the asymmetric process.
