Visible Light-Induced Thiocyanation of Enaminone C-H Bond to Access Polyfunctionalized Alkenes and Thiocyano Chromones

The visible light induced C-H bond thiocyanation on the alpha-site of tertiary enaminones has been realized under metal-free, photocatalytic conditions in the presence of Rose Bengal, which enables the synthesis of thiocyanated alkene derivatives and chromones using NH4SCN as the thiocyano source under an aerobic atmosphere. In addition, employing Ru(bpy)(3)Cl-2 center dot 6H(2)O as the photocatalyst switches the reaction pathway to provide NH2-functionalized thiocyanated enamines via the difunctionalization process consisting of C-H bond thiocyanation and vinyl C-N bond transamination.