Transition metal-free tunable synthesis of 3-(trifluoromethylthio) and 3-trifluoromethylsulfinyl chromones via domino C-H functionalization and chromone annulation of enaminones

The new reactions between o-hydroxyphenyl enaminones and Langlois reagent (CF3SO2Na) for the tunable synthesis of 3-(trifluoromethylthio) chromones and 3-trifluoromethylsulfinyl chromones are reported herein. Both type of reactions proceed under transition metal-free conditions. In addition, the conditions for the synthesis of 3-trifluoromethylsulfinyl chromones have also been found to be applicable for the synthesis of 3-alkyl/arylsulfinyl chromones.