Tandem Sulfonylative Annulation/Halogenation of 1,7-Enynes with Sodium Sulfinate and TBAX for the Assembly of 4-Methylenechromanes

J Org Chem. 2024 Feb 16;89(4):2351-2363. doi: 10.1021/acs.joc.3c02367. Epub 2024 Feb 1.

Abstract

An effective and stereoselective synthesis of halogenated (E)-4-methylenechromanes with a sulfonyl group was developed via the copper-catalyzed sulfonylative annulation/halogenation of 1,7-enynes, in which sodium sulfinates were used as the sulfonyl reagents and tetrabutylammonium halide provided the halogen sources. The formed alkenyl C-X bonds were valuable and can efficiently undergo the subsequent hydrolysis, alkenylation, alkynylation, arylation, alkylthiolation, and alkoxylation to furnish a series of highly functionalized 4-methylenechromanes.