1318072-81-9Relevant academic research and scientific papers
Gold-Catalyzed Oxidative Cyclization of Tryptamine Derived Enynamides: A Stereoselective Approach to Tetracyclic Spiroindolines
Lin, Meijun,Zhu, Lei,Xia, Jiajin,Yu, Yinghua,Chen, Jianxin,Mao, Zhifeng,Huang, Xueliang
, p. 2280 - 2284 (2018)
In this work, we describe a new gold-catalyzed oxidative cascade cyclization of conjugated enynamides. The reaction could be carried out under relatively mild condition. In presence of a cationic gold catalyst bearing an N-heterocyclic carbene ligand, enynamides derived from tryptamine react with pyridine N-oxide, leading to the formation of a variety of tetracyclic spiroindolines in a stereoselective manner. (Figure presented.).
Br?nsted Acid-Catalyzed Tandem Cyclizations of Tryptamine-Ynamides Yielding 1H-Pyrrolo[2,3-d]carbazole Derivatives
Wang, Yanshi,Lin, Jingsheng,Wang, Xiaoyu,Wang, Guanghui,Zhang, Xinhang,Yao, Bo,Zhao, Yuandong,Yu, Pengfei,Lin, Bin,Liu, Yongxiang,Cheng, Maosheng
, p. 4026 - 4032 (2018)
Ynamides, as versatile synthetic precursors, have attracted much attention from synthetic chemists and sparked the development of a number of methodologies for the construction of various structures. 1H-Pyrrolo[2,3-d]carbazole is a core scaffold of a series of monoterpene indole alkaloids found in Kopsia, Strychnos, and Aspidosperma, for example. In this study, 1H-pyrrolo[2,3-d]carbazole derivatives were synthesized by a Br?nsted acid-catalyzed tandem cyclization starting from tryptamine-based ynamides. This strategy prevented Wagner–Meerwein rearrangement by instantaneous intramolecular nucleophilic trapping of the indoleninium to afford a tetracyclic indoline via an in situ-formed enol species induced by the formation of a more stable conjugate diene moiety. The functional group tolerances were investigated by using a series of readily available substrates. A plausible mechanism has been proposed based on the evidence of the capture of the hemiaminal intermediate. Lastly, a Büchi ketone, which is the pivotal intermediate in the synthesis of the indole alkaloid vindorosine, was synthesized by utilizing our newly developed methodology.
Diels-Alder Cycloaddition of Azepino[4,5-b]indoles Towards Hydrocarbazole Derivatives and Related Heterocycles
Xie, Fukai,Li, Xiang,Xu, Liangyu,Ma, Jun,Sun, Lei,Zhang, Bo,Lin, Bin,Cheng, Maosheng,Liu, Yongxiang
, p. 873 - 889 (2022/01/26)
An approach to hydrocarbazoles bearing an all-carbon quaternary center at C4a position was developed via a Br?nsted acid-initiated Diels-Alder cycloaddition/retro-aza-Michael addition cascade process from azepino[4,5-b]indoles and commercially available d
Ligand-Controlled Regiodivergence for Catalytic Stereoselective Semireduction of Allenamides
Hajiloo Shayegan, Mojtaba,Li, Zhong-Yuan,Cui, Xin
supporting information, (2021/12/02)
Ligand-controlled regiodivergence has been developed for catalytic semireduction of allenamides with excellent chemo- and stereocontrol. This system also provides an example of catalytic regiodivergent semireduction of allenes for the first time. The divergence of the semireduction is enabled by ligand switch with the same palladium pre-catalyst under operationally simple and mild conditions. Monodentate ligand XPhos exclusively promotes selective 1,2-semireduction to afford allylic amides, while bidentate ligand BINAP completely switched the regioselectivity to 2,3-semireduction, producing (E)-enamide derivatives.
Preparation method of azepano[4,5-b]indole compound
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, (2021/07/17)
The invention discloses a preparation method of an azepano[4,5-b]indole compound, which comprises the following steps: by taking tryptamine or a derivative thereof as an initial raw material, protecting an NH2 group of a side chain alkyl group, protecting
Exploration of a KI-catalyzed oxidation system for direct construction of bispyrrolidino[2,3-: B] indolines and the total synthesis of (+)-WIN 64821
Chen, Si-Kai,Yang, Ju-Song,Dai, Kun-Long,Zhang, Fu-Min,Zhang, Xiao-Ming,Tu, Yong-Qiang
supporting information, p. 121 - 124 (2019/12/30)
A facile and environmentally benign KI(cat.)/NaBO3·4H2O oxidation system has been developed for the tandem oxidative aminocyclization/coupling of tryptamines, affording a series of 3a,3a′-bispyrrolidino[2,3-b]indolines with high efficiency (up to 94% yield). This reaction features an electrophilic "I+" mechanism, which is importantly quite different from and milder than the typical radical-involving process, and can be readily amplified for the total synthesis of (+)-WIN 64821.
Ynesulfonamide-Based Silica Gel and Alumina-Mediated Diastereoselective Cascade Cyclizations to Spiro[indoline-3,3′-pyrrolidin]-2-ones under Neat Conditions
Wang, Yanshi,Wang, Xiaoyu,Lin, Jingsheng,Yao, Bo,Wang, Guanghui,Zhao, Yuandong,Zhang, Xinhang,Lin, Bin,Liu, Yang,Cheng, Maosheng,Liu, Yongxiang
, p. 1483 - 1492 (2018/03/01)
The spiro[indoline-3,3′-pyrrolidin]-2-ones were synthesized via a silica gel and alumina-mediated sequential transformation based on tryptamine-derived ynesulfonamide substrates under neat conditions. The inherent tendency of C?C bond migration through Wagner-Meerwein rearrangement in the synthesis of spirooxindole was prevented by water trapping to the spiroindoleninium intermediate. The functional group tolerances of the methodology were investigated using a variety of substrates. The detailed mechanism of the sequential transformation was probed by the isotope-labeled experiments. This strategy was further applied in the formal syntheses of indole alkaloids coerulescine and horsfiline. (Figure presented.).
Synthesis of Carbolines via Palladium/Carboxylic Acid Joint Catalysis
Cera, Gianpiero,Lanzi, Matteo,Balestri, Davide,Della Ca, Nicola,Maggi, Raimondo,Bigi, Franca,Malacria, Max,Maestri, Giovanni
supporting information, p. 3220 - 3224 (2018/06/11)
The combination of a Pd(0) complex with benzoic acid converts propargylic tryptamines to the corresponding tetrahydro-β-carbolines. The method uses unprotected indoles and affords the desired products with ample functional group tolerance. Detailed modeling studies reveal a close synergy between the organic and metal catalysts, which enables sequential alkyne isomerization, indole C-H activation, and eventual C-C reductive elimination to afford the target heterocycles.
Gold-Catalyzed Intramolecular Tandem Cyclization of Indole-Ynamides: Diastereoselective Synthesis of Spirocyclic Pyrrolidinoindolines
Zheng, Nan,Chang, Yuan-Yuan,Zhang, Li-Jie,Gong, Jian-Xian,Yang, Zhen
, p. 371 - 375 (2016/05/19)
A gold-catalyzed intramolecular tandem cyclization of indole-ynamide affords tetracyclic spirocyclic pyrrolidinoindoline bearing an all-carbon quaternary stereocentre in a single step; however, when the reaction was carried out in the presence of BF3·Et2O, the corresponding tricyclic spirocyclic pyrrolidinoindoline-based enones are produced through a key 1,5-hydride shift. The developed chemistry provides a diastereoselective and straightforward entry to structurally diverse polycylic pyrrolidinoindolines from indole-ynamides in one-pot reactions under mild conditions.
CuCl2/TBHP-mediated direct chlorooxidation of indoles
Wang, Huifei,Liu, Dong,Chen, Huiyu,Li, Jing,Wang, David Zhigang
, p. 7073 - 7076 (2015/08/19)
CuCl2/TBHP-mediated direct chlorooxidation of indole derivatives under simple aerobic conditions was reported, leading to facile preparations of a range of 3,3-disubstituted 3-chlorooxindoles in good yields and selectivities.
