A Green and Efficient Approach for the Synthesis of 3-Chalcogen Benzo[b]Furans via I₂-Mediated Cascade Annulation Reaction of 2-Alkynylanisoles at Room Temperature in Water

Abstract

An efficient and green aqueous protocol to access 3-chalcogen benzo[b]furan derivatives has been developed. The reaction can proceed via I₂-mediated intramolecular annulation reaction of 2-alkynylanisoles with diaryl disulfides (diselenides) in water or under solvent-free conditions at room temperature. With the participation of I₂, a variety of 3-chalcogen benzo[b]furan derivatives were obtained in good to excellent yields. This reaction was considered to work via an iodocyclization cascade mechanism and the intermediate 3-iodo-2-phenylbenzofuran was detected by GC-MS.

GRAPHICAL ABSTRACT

Keywords:

• 3-chalcogen benzo[b]furans
• I₂-mediated intramolecular annulation

Acknowledgments

The authors thank the National Natural Science Foundation of China (No. 20972114) and the Zhejiang Provincial Natural Science Foundation of China (Y4100578).