110359-08-5Relevant articles and documents
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
, p. 4776 - 4786 (2018)
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.
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.
