A chromatographic relay conjugated photoredox strategy: S, Se-pharmacophore from alkenes via formal [2+2+1] heteroannulation

Abstract

An expedient route to 2-aminodihydrothiophenes and their seleno analogues is reported. A three-component photoredox reaction between alkene, thio(seleno)cyanate, and bromomalonate is employed, generating a carbo-thio(seleno)cyanate intermediate that undergoes a domino of reactions mediated by alumina column chromatography, leading to valuable chalcogen pharmacophores. Mechanistic investigations using DFT and control experiments reveals an intramolecular H-bond responsible for driving the domino forward.