Khan DM, Lv J, Hua R. Copper(I)-Catalyzed Formal [4 + 2] Cyclocondensation of
ortho-Hydroxybenzyl Alcohol, Aromatic Terminal Alkynes, and Sulfonyl Azides: An Alternative Approach to 2-Sulfonyliminocoumarins.
Molecules 2024;
29:3426. [PMID:
39065004 PMCID:
PMC11279675 DOI:
10.3390/molecules29143426]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/07/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024] Open
Abstract
In this paper, an alternative and efficient copper(I)-catalyzed synthesis of 2-sulfonyliminocoumarins is developed through a three-component reaction of ortho-hydroxybenzyl alcohol, alkynes, and p-toluenesulfonyl azide. The proposed route for access to the 2-iminocoumarin ring involves a [4 + 2] hetero-Diels-Alder reaction between ortho-quinone methide and ketenimine intermediates generated in situ.
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