A visible light mediated alkyl sulfonylative cascade using Hantzsch esters via SO2 insertion

Abstract

We hereby report a visible light mediated alkyl sulfonylative cascade cyclization of alkynyl and dialkynyl cyclohexadienones via SO₂ insertion. The protocol utilizes alkyl Hantzsch esters as the alkyl source and DABSO as the SO₂ source with 4-CzIPN as the organophotocatalyst. A variety of dihydrochromenone derivatives were obtained in good yields under mild energy efficient conditions. Additionally, fluorescence quenching and control studies were carried out to probe the mechanism.