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Synthesis 2019; 51(22): 4263-4270
DOI: 10.1055/s-0039-1690680
paper
© Georg Thieme Verlag Stuttgart · New York

Metal-Free Hydroamination of Alkynes: A Mild and Concise Synthesis of Thiazolo[3,2-a]indoles and their Cytotoxic Activity

Spencer Short 
a   Department of Biology and Chemistry, Nipissing University, 100 College Drive, North Bay, ON P1B 8L7, Canada   Email: mukundj@nipissingu.ca
,
Steven Rhodes
a   Department of Biology and Chemistry, Nipissing University, 100 College Drive, North Bay, ON P1B 8L7, Canada   Email: mukundj@nipissingu.ca
,
Vishakha S. Bhave
b   School of Pharmacy, Philadelphia College of Osteopathic Medicine, Suwanee, GA 30024, USA
,
Ryoga Hojo
a   Department of Biology and Chemistry, Nipissing University, 100 College Drive, North Bay, ON P1B 8L7, Canada   Email: mukundj@nipissingu.ca
,
Mukund Jha  ∗
a   Department of Biology and Chemistry, Nipissing University, 100 College Drive, North Bay, ON P1B 8L7, Canada   Email: mukundj@nipissingu.ca
› Author AffiliationsThe authors gratefully acknowledge the financial support provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), Nipissing University, the Canada Foundation for Innovation (CFI) and the Northern Ontario Heritage Fund Corporation (NOHFC) to conduct this research.
Further Information

Publication History

Received: 08 July 2019

Accepted after revision: 29 August 2019

Publication Date:
24 September 2019 (online)

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Abstract

A metal-free, mild and efficient method for the synthesis of thiazolo[3,2-a]indoles has been developed starting from indoline-2-thiones. The reaction methodology involves first the formation of thermally labile 2-(prop-2-ynylthio)-1H-indole intermediates, which undergo base-mediated intramolecular hydroamination to produce the title compounds in excellent yields.

Key words

indole-fused heterocycles - thiazolo[3,2-a]indoles - metal-free hydroamination - indoline-2-thiones - intramolecular cyclization

Supporting Information

    Supporting information for this article is available online at https://doi.org/10.1055/s-0039-1690680.
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