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Synlett
DOI: 10.1055/a-2659-8340
Letter

Asymmetric Isochalcogenourea-Catalyzed Synthesis of 3,4-Dihydropyrans via (4+2)-Cycloadditions of Ethyl But-3-ynoate with Michael Acceptors

Mario Hofer
1   Institute of Organic Chemistry, Johannes Kepler University Linz, Linz, Austria (Ringgold ID: RIN27266)
,
Magdalena Piringer
1   Institute of Organic Chemistry, Johannes Kepler University Linz, Linz, Austria (Ringgold ID: RIN27266)
,
Anna Scheucher
1   Institute of Organic Chemistry, Johannes Kepler University Linz, Linz, Austria (Ringgold ID: RIN27266)
,
Lukas S. Vogl
1   Institute of Organic Chemistry, Johannes Kepler University Linz, Linz, Austria (Ringgold ID: RIN27266)
,
Mario Waser 
2   Inst. f. Org. Chemie, Joh. Kepler Univ. Linz, Linz, Austria
› Author Affiliations
Supported by: Austrian Science Fund 10.55776/P36004,P36004
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We herein report the use of ethyl but-3-ynoate as a C2 building block for asymmetric (4+2)-heterocycloadditions with various Michael acceptors. Upon using chiral isochalcogenoureas as Lewis base catalysts, these reactions can be carried out with good to excellent control of the regioselectivity, diastereoselectivity, and enantioselectivity.



Publication History

Received: 23 May 2025

Accepted after revision: 18 July 2025

Accepted Manuscript online:
18 July 2025

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