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Synlett 2023; 34(05): 465-470
DOI: 10.1055/a-1908-3876
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Special Edition Thieme Chemistry Journals Awardees 2022

Construction of Spiropyrroloindolines by Dearomative [3+2]-Cycloaddition of Indoles with Oxindole-Embedded Azaoxyallyl ­Cations

Bandana Singh
a   Department of Synthetic and Biological Chemistry, Centre of Biomedical Research (CBMR), SGPGIMS Campus, Lucknow-226014, India
b   Department of Chemistry, Banaras Hindu University, Varanasi-221005, India
,
Tishyasoumya Bera
a   Department of Synthetic and Biological Chemistry, Centre of Biomedical Research (CBMR), SGPGIMS Campus, Lucknow-226014, India
,
Vinod P. Singh
b   Department of Chemistry, Banaras Hindu University, Varanasi-221005, India
,
Priyasha Priyasha
c   School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India
,
Dinabandhu Das
c   School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India
,
Jaideep Saha  ∗
a   Department of Synthetic and Biological Chemistry, Centre of Biomedical Research (CBMR), SGPGIMS Campus, Lucknow-226014, India
› Author AffiliationsThis work was supported by research funding to J.S. by SERB (CRG/2020/000381) and CSIR-EMR-II (02(0395)/21/EMR-II). B.S. thanks CSIR for a fellowship. T.S.B. is a DST-INSPIRE fellow.
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Abstract

A dearomative [3+2]-cycloaddition reaction of oxindole-embedded azaoxyallyl cations with indoles at the C3 position has been developed. The use of this new class of azaoxyallyl cation species in the reaction permits access to more-elaborate hexahydropyrrolo[2,3-b]indole moieties that contain a spiro-oxindole ring. The transformation displays a broad substrate scope and good regio- and stereoselectivity for the cycloaddition step. Several observations suggested that this class of azaoxyallyl cations can display a different reactivity pattern from those of commonly employed azaoxyallyl cation systems.

Key words

indoles - dearomatization - azaoxyallyl cations - oxindoles - cycloaddition - indolines

Supporting Information



Publication History

Received: 28 June 2022

Accepted after revision: 25 July 2022

Accepted Manuscript online:
25 July 2022

Article published online:
01 September 2022

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  • References and Notes


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