Synthesis 2022; 54(22): 4917-4931
DOI: 10.1055/a-1868-4148
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Use of Vinyl Sulfides in Fischer Indole Reactions

Parul Pal
,
Meghan Fragis
,
,
,
Jakob Magolan
This research was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN-2018-06438), the McMaster University’s Faculty of Health Sciences Dean’s Fund, and by a generous endowed gift from the Boris Family. M.F. was supported by a Canada Graduate Scholarship (CGS-M).


Abstract

Vinyl sulfides accessed via Wittig olefination with thioalkylphosphonium salts are used as aldehyde- or ketone surrogates in Fischer indole reactions. These vinyl sulfides react with arylhydrazines in the presence of TsOH·H2O in refluxing ethanol or dichloroethane to yield diverse 3-substituted and 2,3-disubstituted indoles or azaindoles. The utility of this chemistry is highlighted with the efficient preparation of three biomedically relevant compounds: 4-aza-melatonin, a furoindoline, and an indomethacin-like CRTh2 antagonist.

Supporting Information



Publication History

Received: 13 April 2022

Accepted after revision: 02 June 2022

Accepted Manuscript online:
02 June 2022

Article published online:
12 July 2022

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