Synthesis of Spirocyclic Indolenines

This Review provides an in‐depth account of the synthesis of spirocyclic indolenines. Over the last 77 years, a wide array of diverse synthetic methods has been developed in order to generate these synthetically useful and biologically important spirocyclic scaffolds. The main synthetic strategies discussed are grouped into three main categories, namely interrupted Fischer indolisations, dearomatisation reactions of indoles and condensation reactions. The historical background, common synthetic challenges, current state‐of‐the‐art and future perspectives of this field are examined.     

An Indoxyl‐Based Strategy for the Synthesis of Indolines and Indolenines

An indoxyl‐based strategy for the synthesis of indolines and indolenines via unprecedented aza‐pinacol and aza‐semipinacol rearrangements was developed. This method provides direct access to the core structures of several classes of indole alkaloids. The synthetic utility was demonstrated by the divergent synthesis of an array of functionalized polycyclic structures from a common intermediate and the formal total synthesis of the indoline natural product minfiensine. The reversed reactivity of indoxyl as a building block compared to that of indole offers a conceptually distinct disconnection strategy for indoline‐ and indolenine‐containing heterocycles and natural products.     

Crown ether-containing styryl dyes

The method for the synthesis of indoles from nitropyridinium salts has been improved. A method for synthesizing novel derivatives of indoleninium quaternary salts has been developed. The condensation of indoleninium salts with formyl derivatives of crown ethers leading to styryl dyes is described. Photoisomerization and complexing of crown-ether dyes with ions of alkaline and alkaline-earth metals have been studied. The shift of the long-wave absorption maximum has been observed to depend on the size and charge density of the metal cation.For communication 8, see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1625–1632, September, 1993.     

Chemistry of heterocyclic compounds at the Institute of Organic Chemistry,National Academy of Sciences of Ukraine (Review)

The present work is dedicated to the 70th anniversary of the Institute of Organic Chemistry, National Academy of Sciences of Ukraine. It contains a review of achievements in the chemistry of heterocyclic compounds, a brief historical account, and information on the work of the Institute’s team in recent years. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–513, April, 2009.     

Silver(I)‐ or Copper(II)‐Mediated Dearomatization of Aromatic Ynones: Direct Access to Spirocyclic Scaffolds

A high‐yielding silver(I)‐ or copper(II)‐catalyzed dearomatizing spirocyclization strategy allows the conversion of simple aromatic compounds that contain ynone substituents, including indole, anisole, pyrrole, and benzofuran derivatives, into functionalized spirocyclic scaffolds. A high‐yielding asymmetric variant furnishes spirocyclic indolenines in up to 89:11 e.r.     

Synthesis of carboxyalkylindolenines from 6-methyl-7-oxooctanoic acid

Novel 3-(4-carboxybutyl)indolenines were obtained. A method for the synthesis of 6-methyl-7-oxooctanoic acid, the precursor for these indolenines, was developed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 595–598, March, 2008.     

Novel asymmetric indodicarbocyanine dyes

Novel indodicarbocyanine dyes functionalized at position 5 of the indolenine system were obtained and characterized by spectroscopic methods. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2186–2190, November, 2007.