Synlett 2025; 36(10): 1358-1362
DOI: 10.1055/s-0043-1773527
letter

Application of the Intramolecular Didehydro-Diels–Alder (IMDDA) Reaction for the Synthesis of Thieno[2,3-f]isoindole-4(8)-carboxylic Acids

Evgeniya R. Shelukho
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
,
Elizaveta D. Yakovleva
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
,
Nikita A. Logvinenko
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
,
Victor N. Khrustalev
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
b   Zelinsky Institute of Organic Chemistry of RAS, 47 Leninsky Prospect, 119991 Moscow, Russian Federation
,
Roman A. Novikov
с   V. A. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov St., Moscow, 119991, Russian Federation
,
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
,
a   RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
› Author Affiliations

This publication has been supported by the Russian Science Foundation (project no. 24-23-00212), see https://rscf.ru/project/24-23-00212/.


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Abstract

The reaction of 3-(thienyl)propargylamines with maleic anhydride, followed by a domino sequence involving successive acylation/[4+2] cycloaddition steps, leads to the formation of the thieno[2,3-f]isoindole core. The key step, the intramolecular didehydro-Diels–Alder (IMDDA) reaction, proceeds with a high level of selectivity, yielding the target products – 7-oxo-5,6,7,8-tetrahydro-4H-thieno[2,3-f]isoindole-4(8)-carboxylic acids – in good yields. X-ray analysis and DFT calculations have revealed that the key step, the IMDDA reaction, proceeds via an exo transition allene state, resulting in the exclusive formation of a single isomer of the target heterocycle.

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Publication History

Received: 27 September 2024

Accepted after revision: 10 February 2025

Article published online:
06 May 2025

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