Photocatalytic three-component annulation enabling stereoselective generation of (Z)-thiochromene 1,1-dioxides

Abstract

A new photocatalytic three-component annulation of 2-alkynylaryldiazonium tetrafluoroborates with γ-hydroxyl terminal alkynes and sodium metabisulfite is reported using fac-Ir(ppy)₃ as the photocatalyst for the first time and used to produce a series of (Z)-thiochromene 1,1-dioxides bearing an exocyclic double bond with moderate to good yields in a highly stereoselective manner. A wide variety of easily available substrates with substituent diversity could successfully participate in this photocatalysis with good functional group tolerance.