Synthesis of Functionalized Dihydrocoumarins by NHC-Catalyzed 3 + 3 Annulation of Enals with 2-Substituted Naphthoquinones

Shee, S and Barik, S and Ghosh, A and Biju, AT (2021) Synthesis of Functionalized Dihydrocoumarins by NHC-Catalyzed 3 + 3 Annulation of Enals with 2-Substituted Naphthoquinones. In: Organic Letters, 23 (20). 8039 -8044.

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Abstract

The 3 + 3 annulation of α,β-unsaturated aldehydes with 2-substituted 1,4-naphthoquinones allowing the facile synthesis of functionalized dihydrocoumarins catalyzed by N-heterocyclic carbene (NHC) is reported. The initially formed NHC-homoenolates underwent an efficient Michael-isomerization-lactonization cascade to furnish the products. Preliminary studies on mechanism shed light on the homoenolate pathway over the intermediacy of the α,β-unsaturated acylazolium intermediates. Moreover, using chiral NHCs, the desired products were formed in up to 49% yield and 99:1 er. ©

Item Type:	Journal Article
Publication:	Organic Letters
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	26 Nov 2021 10:49
Last Modified:	26 Nov 2021 10:49
URI:	http://eprints.iisc.ac.in/id/eprint/70465

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