Synthesis of Indolyl‐1,3‐dienes from β‐Sulphonyl Aldehydes through One‐Pot Sequential Brønsted Acid/Base Catalysis
Introduction of a 1,3‐diene moiety at the C3‐position of pyrrole and indole bearing various aliphatic as well as aromatic functional groups with good stereoselectivity remains a challenging task. Keeping the synthetic applicability in mind, an eccentric strategy is developed to synthesize 1,3‐dienyl...
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Published in | European journal of organic chemistry Vol. 2022; no. 18 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
Wiley Subscription Services, Inc
13.05.2022
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Subjects | |
Online Access | Get full text |
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Summary: | Introduction of a 1,3‐diene moiety at the C3‐position of pyrrole and indole bearing various aliphatic as well as aromatic functional groups with good stereoselectivity remains a challenging task. Keeping the synthetic applicability in mind, an eccentric strategy is developed to synthesize 1,3‐dienyl pyrroles and indoles from unprotected pyrroles and indoles employing β‐sulphonyl aldehyde as a dienylating agent. This method is developed by using a one‐pot sequential Brønsted acid/base catalysis strategy. The nucleophilicity of indole is transmitted through the conjugation to eliminate the sulfonyl groups in a step‐wise manner. Further, this developed protocol was extended to the incorporation of a 1,3,5‐triene moiety at the C3‐position of indoles through unprecedented successive three sulfonyl group elimination. As an application of this strategy, a Diels−Alder reaction and hydrothiolation of 1,3‐diene were demonstrated.
Syntheses of dienyl pyrroles and indoles were achieved by using β‐sulfonyl aldehydes through transition‐metal‐free one‐pot sequential Brønsted acid/base catalysis. This transformation enables the access to various aliphatic as well as aromatic substituted 1,3‐dienes. Further, trienyl indole was also synthesized employing this strategy. |
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ISSN: | 1434-193X 1099-0690 |
DOI: | 10.1002/ejoc.202200240 |