Iodine-Catalyzed Cascade Annulation of 4-Hydroxycoumarins with Aurones: Access to Spirocyclic Benzofuran-Furocoumarins

Xuequan Wang; Changhui Yang; Dan Yue; Mingde Xu; Suyue Duan; Xianfu Shen

doi:10.3390/molecules29081701

Iodine-Catalyzed Cascade Annulation of 4-Hydroxycoumarins with Aurones: Access to Spirocyclic Benzofuran-Furocoumarins

Molecules. 2024 Apr 9;29(8):1701. doi: 10.3390/molecules29081701.

Authors

Xuequan Wang¹, Changhui Yang¹, Dan Yue¹, Mingde Xu¹, Suyue Duan¹, Xianfu Shen²

Affiliations

¹ School of Chemistry and Resources Engineering, Honghe University, Honghe 661100, China.
² College of Chemistry and Environmental Science, Qujing Normal University, Qujing 655011, China.

Abstract

An attractive approach for the preparation of spirocyclic benzofuran-furocoumarins has been developed through iodine-catalyzed cascade annulation of 4-hydroxycoumarins with aurones. The reaction involves Michael addition, iodination, and intramolecular nucleophilic substitution in a one-step process, and offers an efficient method for easy access to a series of valuable spirocyclic benzofuran-furocoumarins in good yields (up to 99%) with excellent stereoselectivity. Moreover, this unprecedented protocol provides several advantages, including readily available materials, an environmentally benign catalyst, a broad substrate scope, and a simple procedure.

Keywords: benzofuran; furocoumarin; iodine-catalyzed cascade annulation; spiro-heterocycle.

Grants and funding

This research was funded by the Natural Science Foundation of Yunnan Province (Nos. 202101BA070001-053, 202205AC160004, 202301BA070001-102) and the Program for Innovative Research Team in Qujing University.