139655-04-2Relevant articles and documents
Microwave assisted Pictet-Spengler and Bischler-Napieralski reactions
Pal, Bikash,Jaisankar, Parasuraman,Giri, Venkatachalam S.
, p. 2339 - 2348 (2003)
Pictet-Spengler and Bischler-Napieralski reaction products have been prepared-using microwave irradiation on silicagel support under solvent free condition. Microwave assisted reactions have resulted in better yields of the desired products than prepared
Selective construction of alkaloid scaffolds by alcohol-based direct and mild aerobic oxidative Pictet-Spengler reactions
Han, Feng,Li, Huan,Liu, Haicheng,Liu, Jianping,Xu, Qing
supporting information, p. 7079 - 7085 (2020/10/02)
Employing TBN/TEMPO as the catalysts and oxygen as the oxidant, the biologically and pharmaceutically significant tetrahydro-β-carboline and β-carboline alkaloid scaffolds that used to be obtained by multi-step processes can now be selectively obtained in only one-stepviadirect aerobic oxidative Pictet-Spengler reactions of tryptamines with alcohols under mild conditions, with water generated as the byproduct. In this reaction, TBN/TEMPO was interestingly found to be able to facilitate the cyclization step of the whole reaction. This method tolerates a variety ofC- andN-substituted tryptamines, and both the more reactive benzylic and allylic alcohols and the less reactive aliphatic alcohols. This method can also be extended to dihydro-β-carboline synthesis and applied to the more available and more economical tryptophan for β-carboline synthesis, revealing its broad substrate scope and potential in synthetic applications.
Iodine-Catalyzed Metal-Free Oxidative Ring Opening of 1-Aryltetrahydro-β-carbolines: Facile Synthesis of C-2 Aroyl and Aryl Methanimino Indole Derivatives
Chauhan, Jyoti,Luthra, Tania,Sen, Subhabrata
supporting information, p. 4776 - 4786 (2018/09/06)
Indole derivatives bearing C-2 substituents have garnered a lot of attention due to their diverse biological activities. Various methods forthe synthesis of these compounds have been reported. Inspired by the hydrolysis of imines, an oxidative ring-opening reaction of 1-aryltetrahydro-β-carbolines with catalytic iodine in aqueous hydrogen peroxide, and also in the presence of appropriate amines, is described for the generation of 2-aroyl and arylmethanimine indole derivatives. The reaction proceeds under mild reaction conditions with ethanol as the solvent or under solvent-free conditions, respectively. This metal-free strategy facilitates the formation of the desired substituted C-2 indoles in moderate to excellent yields. The utility of this reaction is demonstrated by a facile multigram-scale synthesis of Luzindole, a selective melatonin receptor antagonist and an investigational drug against depression and disruption of the circadian rhythm.