646995-91-7Relevant academic research and scientific papers
Enantioselective Synthesis of 3-Substituted 3-Amino-2-oxindoles by Amination with Anilines
Yang, Wenkun,Dong, Pei,Xu, Jian,Yang, Jian,Liu, Xiaohua,Feng, Xiaoming
, p. 9272 - 9275 (2021/06/01)
A chiral N,N′-dioxide-nickel(II) complex-catalyzed asymmetric amination of 3-bromo-3-substituted oxindoles with anilines has been developed. A series of alkyl or aryl 3-amino-indolinones with quaternary stereocenters were obtained in high yields with excellent ee values in one step (up to 99 % yield, up to 96 % ee). The method provided a ready route to optically active intermediates of 3-amino-2-oxindole-based bioactive compounds. Moreover, a possible transition-state model is proposed so as to elucidate the origin of the chirality based on the X-ray crystal structure of the catalyst and the adduct.
Ammonium hydroxide as the ultimate amino source for the synthesis of: N -unprotected 3-tetrasubstituted aminooxindoles via catalyst-free direct amination
Yue, Jing,Ma, Xi-Tao,Liu, Xiong-Li,Wang, Jun-Xin,Liu, Xiong-Wei,Zhou, Ying
supporting information, p. 1837 - 1841 (2020/04/08)
The direct use of ammonium hydroxide in amination for the synthesis of primary amines is considered to be one of the major challenges in synthetic organic chemistry. Herein, the first example of catalyst-free direct amination of 3-halooxindoles with ammonium hydroxide to synthesize N-unprotected 3-tetrasubstituted aminooxindoles in high yields (up to 91% yield) is described. An enhancement of the reaction rate on using water was observed under mild conditions. Such an approach is not only protection/deprotection-free, but also more practical and cost-effective. Moreover, this method could expand the library of 3-tetrasubstituted aminooxindole building blocks for the further synthesis of AG-041R, GHSR antagonists and a charteline unit, opening up a new synthetic pathway in the chemistry of 3-aminooxindoles.
Copper-catalyzed oxoazidation and alkoxyazidation of indoles
Yin, Hang,Wang, Teng,Jiao, Ning
, p. 2302 - 2305 (2014/05/20)
Copper-catalyzed oxoazidation and alkoxyazidation of indoles has been developed. The dearomatization reaction which leads to versatile 3-azido indolenine and oxindole derivatives in moderate to good yields could be used in a further transformation.
Facile and efficient enantioselective hydroxyamination reaction: Synthesis of 3-hydroxyamino-2-oxindoles using nitrosoarenes
Shen, Ke,Liu, Xiaohua,Wang, Gang,Lin, Lili,Feng, Xiaoming
supporting information; experimental part, p. 4684 - 4688 (2011/06/22)
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 effi
Highly enantioselective synthesis of 3-amino-2-oxindole derivatives: Catalytic asymmetric α-amlnation of 3-substituted 2-oxindoles with a chiral scandium complex
Yang, Zhigang,Wang, Zhen,Bai, Sha,Shen, Ke,Chen, Donghui,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
supporting information; experimental part, p. 6632 - 6637 (2010/08/20)
A highly enantioselective α-amination of 3-substituted oxindoles with azodicarboxylates catalyzed by a chiral Sc(OTf)3/N,/N′-dioxide complex (Tf: triflate) has been developed and affords the corresponding 3-amino-2-oxindole derivatives in high yields (up to 98%) with excellent enantioselectivities (up to 99% ee). The procedure is capable of tolerating a relatively wide range of substrates, and excellent results (92-96 % ee) can also be obtained, even in the presence of 0.5 mol % of catalyst loading under mild conditions. These results showed the potential value of the catalytic approach. Moreover, with high synthetic versatility, the product could be easily transformed into optically active 3-amino-3-methyloxindole bearing a chiral quaternary stereogenic center.
A Concise Synthesis of Sterically Hindered 3-Amino-2-Oxindoles
O'Connor, Stephen J.,Liu, Zheng
, p. 2135 - 2138 (2007/10/03)
A new method for the synthesis of 3-alkyl-3-amino-2-oxindoles is reported. These compounds are prepared in a 3-step procedure using a base-mediated nucleophilic addition of benzylidene-imine protected α-aminoesters to 2-nitrofluorobenzene as the key step. The process provides a variety of 3-alkyl-3-amino-2-oxindole analogs in yields of 1-24%. Yields are highest with alanine, phenylalanine and 2-pyridylalanine as the amino acid starting materials, while 3-pyridylalanine and O-methyltyrosine are less efficiently arylated. Sterically hindered amino acids such as valine and phenylglycine are for all practical purposes, not substrates for the key nucleophilic substitution reaction. The resulting 3-alkyl-3-amino-2-oxindoles are important intermediates for the preparation of drug-like substances. The conversion of alanine ethyl ester to 3-amino-3-methyl-2-oxindole is described.
