title: Pseudopericyclic 1,5- versus Pericyclic 1,4- and 1,6-Electrocyclization in Electron-Poor 4‑Aryl-2-azabuta-1,3-dienes: Indole Synthesis from 2H‑Azirines and Diazo Compounds
metadata.name: dc.contributor.author
metadata.value: Novikov, Mikhail S.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Khlebnikov, Alexander F.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Rostovskii, Nikolai V.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Tcyrulnikov, Sergei
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Suhanova, Anna A.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Zavyalov, Kirill V.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Yufit, Dmitry S.
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2016-04-07T21:14:47Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2016-04-07T21:14:47Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2015-01
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: J. Org. Chem. 2015, 80, 18−29
metadata.lang: en_GB
metadata.name: dc.identifier.issn
metadata.value: 0022-3263
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/1960
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: Transformations of 2-azabuta-1,3-dienes, formed in Rh2(OAc)4-catalyzed reactions of diazo carbonyl compounds with 2H-azirines, dramatically depend on the nature of substituents. 4,4-Diphenyl-2-azabuta-1,3-dienes with two electron-acceptor substituents at C1 undergo thermal 1,5-cyclization to give indoles in good yields. The increase in electronwithdrawing ability of C1-substituents facilitates the reaction that proceeds via pseudopericyclic 1,5-electrocyclization of 2-azabutadiene into 7aH-indolium ylide followed by prototropic
  shift. 3,4-Diphenyl-2-azabuta-1,3-dienes, resulting from reaction of 2,3-diphenyl-2H-azirine and diazo compounds, do not produce indoles via 1,5-cyclization due to the trans-configuration of the 4-Ph-group and the nitrogen, but undergo 1,4-cyclization to 2,3-dihydroazetes. 1,6-Cyclization into 2H-1,4-oxazines with participation of the oxygen of ester or amide group at C1 of corresponding 2-azabuta-1,3-dienes does not take place due to kinetic and thermodynamic reasons. Instead of this, 1,6-electrocyclization with participation of phenyl substituent at C4 of the 2-azabuta-1,3-dienes, providing isoquinoline derivatives, can occur at elevated temperatures. The DFT-calculations (mPWB1K/6-31+G(d,p)) confirm the dependence of 2-azabuta-1,3-diene transformation type on the nature of substituents.
metadata.lang: en_GB
metadata.name: dc.language.iso
metadata.value: en
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: American Chemical Society
metadata.lang: en_GB
metadata.name: dc.relation.ispartofseries
metadata.value: The Journal of Organic Chemistry;Vol. 80
metadata.lang: -
metadata.name: dc.subject
metadata.value: 2-azabuta-1,3-dienes
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Indole Synthesis
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Azirines
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Diazo Compounds
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Pseudopericyclic reactions
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Pericyclic reactions
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Pseudopericyclic 1,5- versus Pericyclic 1,4- and 1,6-Electrocyclization in Electron-Poor 4‑Aryl-2-azabuta-1,3-dienes: Indole Synthesis from 2H‑Azirines and Diazo Compounds
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: grafical abstract1.png
resources.url: https://dspace.spbu.ru/bitstream/11701/1960/1/grafical%20abstract1.png
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