Thioxanthrone-based ionic liquid as efficient and recyclable photocatalyst for α-cyanidation reaction of aromatic tertiary amines

A stabile and recyclable photocatalyst IL-TX was designed and synthesized by introducing the dye photocatalyst thioxanthenone into ionic liquids and its excellent photocatalytic performance was demonstrated by photophysical and electronic performance tests. The IL-TX was applied as a recyclable photocatalyst for α- cyanidation reaction of aromatic tertiary amines in MeOH at room temperature under blue light irradiation, and a range of cyanide products were obtained in good to excellent yields. Furthermore, the practicality of this protocol was further demonstrated through the optimization of the synthesis of the drug praziquantel and the natural product 8-oxopseudopalmatine. This study provides a greener and sustainable solution for photocatalytic cyanation reaction.