Darzens reaction of thioisatins and sulfonium salts: approach to the synthesis of thiochromenone derivatives with anticancer potency

A new Darzens reaction of thioisatins and sulfonium salts has, for the first time, been reported. This reaction allows an efficient access to thiochromenone derivatives in good to excellent yields under mild reaction conditions. The substrate scope includes both electron-withdrawing and electron-donating groups on both the thioisatins and sulfonium salts. Moreover, some of synthesized thiochromenone derivatives have been found to show potent anticancer activities against six different cancer cell lines using the methylthiazoltetrazolium (MTT) assay.