4802-79-3Relevant academic research and scientific papers
Preparation of ethylene glycol abducts at 2,3-positions of indoles with hypervalent iodine
Okada, Naoki,Misawa, Kaori,Kitajima, Mariko,Takayama, Hiromitsu
, p. 461 - 472 (2007)
An efficient method for protection-deprotection of the 2,3-bond of indoles was developed. Treatment of various indole derivatives with hypervalent iodine-ethylene glycol in the presence of ammonium chloride provided 2,3-ethylene glycol bridged adducts in excellent yields. The adducts, which possessed a masked form of pyrrole moiety in the indole nucleus, could be converted back to the mother indoles under mild reductive conditions.
A general strategy for the synthesis of indoloquinolizine alkaloids: Via a cyanide-catalyzed imino-Stetter reaction
Park, Eunjoon,Cheon, Cheol-Hong
, p. 10265 - 10275 (2017)
A new strategy applicable to the synthesis of indoloquinolizine natural products has been developed. A cyanide-catalyzed intramolecular imino-Stetter reaction of aldimines, derived from 2-aminocinnamic acid derivatives and 2-pyridinecarboxaldehydes, provided indole-3-acetic acid derivatives bearing a pyridyl ring at the 2-position. Reduction of the carboxylic acid moiety to an alcohol followed by activation of the resulting alcohol with Tf2O or TsCl generated indoloquinolizinium salts, which were utilized as precursors for indoloquinolizine natural products. The advantage of this protocol was successfully demonstrated in the total syntheses of arborescidine A and nauclefidine.
Palladium-Catalyzed α-Amino C–H Functionalization via Isomerization of α,β-Unsaturated Carbonyls
Cheng, Shao-Jie,Liu, Kui,Wang, Gang,Ye, Zhi-Shi
supporting information, p. 864 - 868 (2022/02/07)
Palladium-catalyzed regioselective α-amino C–H functionalization via the isomerization of α,β-unsaturated carbonyls including esters, ketones, and amides has been established, providing an easy access to a wide array of tricyclic 1,2,3,4-tetrahydro-b-carb
Tf2O/TTBP (2,4,6-Tri-tert-butylpyrimidine): An Alternative Amide Activation System for the Direct Transformations of Both Tertiary and Secondary Amides
He, Qian,Ye, Jian-Liang,Xu, Fang-Fang,Geng, Hui,Chen, Ting-Ting,Chen, Hang,Huang, Pei-Qiang
, (2021/09/28)
Ten types of Tf2O/TTBP-mediated amide transformation reactions were investigated. The results showed that compared with pyridine derivatives 2,6-di-tert-butyl-4-methylpyridine (DTBMP) and 2-fluoropyridine (2-F-Pyr.), TTBP can serve as an alternative amide activation system for the direct transformation of both secondary and tertiary amides. For most surveyed examples, higher or comparable yields were generally obtained. In addition, Tf2O/TTBP combination was used to promote the condensation reactions of 2-(tert-butyldimethylsilyloxy)furan (TBSOF) with both tertiary and secondary amides, the one-pot reductive Bischler-Napieralski-type reaction of tertiary lactams, and Movassaghi and Hill's modern version of the Bischler-Napieralski reaction. The value of the Tf2O/TTBP-based methodology was further demonstrated by the concise and high-yielding syntheses of several natural products.
Oxidative Pictet-Spengler cyclisations through acceptorless iridium-catalysed dehydrogenation of tertiary amines
Cooksey, John P.,Saidi, Ourida,Williams, Jonathan M.J.,Blacker, A. John,Marsden, Stephen P.
, (2020/12/14)
The valuable tetrahydro-β- and γ-carboline skeleta can be accessed through Pictet-Spengler cyclisation initiated by acceptorless dehydrogenation of saturated cyclic amines. The substrate scope for the β-isomers is found to be somewhat limited, but access
One-pot tandem route to fused indolizidines and quinolizidines: Application in the synthesis of alkaloids and bioactive compounds
Song, Qiao,Liu, Yan,Cai, Linlin,Cao, Xinyu,Qian, Shan,Wang, Zhouyu
, p. 1713 - 1716 (2021/03/08)
Fused indolizidines and quinolizidines are important skeletons in a variety of natural products and pharmacologically important compounds. A one-pot tandem route from amide to fused indolizidines and quinolizidines is disclosed. This method is conducted in mild conditions and shows well tolerance of functional groups. It is also easy to be scaled up to gram scale and can be applied smoothly to the total synthesis of alkaloids such as (±)-crispine A, (±)-xylopinine, (±)-desbromoarborescidine A, (±)-harmicine and other bioactive substances.
Synthetic method of tetrahydroisoquino ring compound and tetrahydro-beta-carbo ring compound
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Paragraph 0188-0192, (2020/12/09)
The invention provides a synthetic method of a tetrahydroisoquino ring compound and a tetrahydro-beta-carbo ring compound, and belongs to the technical field of synthesis. According to the method forsynthesizing the tetrahydroisoquino and the tetrahydro-b
Synthesis of 7-Oxo-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine
Tompkins, David C.,Nelson, Randall B.,Dolby, Lloyd J.,Gribble, Gordon W.
, p. 2168 - 2171 (2018/08/03)
A short synthesis of 7-oxo-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine from 2-acetylpyridine and phenylhydrazine is described. Ring C is forged using 2-chloro-N,N-dimethylacetamide. This derivative of the natural alkaloid 1,2,3,4,6,7,12,12b-octah
Synthesis of 6-Oxo-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine
Tompkins, David C.,Reilly, Laurence W.,Nelson, Randall B.,Dolby, Lloyd J.,Gribble, Gordon W.
, p. 1048 - 1052 (2018/04/24)
An efficient synthesis of 6-oxo-1,2,3,4,5,7,12,12b-octahydroindolo[2,3-α]quinolizine from 2-acetylpyridine and phenylhydrazine is described. This derivative of the natural alkaloid desbromoarborescidine A is an important entry point to the sarpagine-vobas
Ene-hydrazide from enol triflate for the regioselective Fischer indole synthesis
Lim, Byeong-Yun,Jung, Bo-Eun,Cho, Cheon-Gyu
supporting information, p. 4492 - 4495 (2015/01/09)
Ene-hydrazide prepared from enol triflate undergoes a Fischer indolization reaction to give the corresponding indole with complete regioselectivity. The starting enol triflate is readily accessed in regiochemically defined form from the ketone precursor via various well-established methods. This new protocol was successfully applied to the synthesis of desbromoarborescidine A, a natural β-carboline alkaloid, difficult to prepare with conventional Fischer indole synthesis.
