Unsymmetric monothiooxalamides from S8, bromodifluoro reagents and anilines: Synthesis and applications

Unsymmetric monothiooxamides as very special and important scaffolds have been widely existing in natural products and bioactive molecules. However, the efficient construction of such compounds are very rare. Herein, we report a simple and practical strategy to achieve unsymmetric monothiooxalamides via S8-mediated defluorination and vulcanization of amines with bromodifluoroalkylative reagents under mild conditions. And the potential applications of such compounds as ligands has been demonstrated in Cu-catalyzed cross coupling reactions. The fluorinated quinoxalinones, benzooxazinone, α-phenyliminoamides, as well as 2-amidobenzothiazoles are obtained in-situ from unsymmetric monothiooxalamides, in which bromodifluoroalkylative reagents undertake selective triple cleavage. Moreover, we also discover that N-aryl-2-amidobenzothiazoles have aggregation-induced luminescence (AIE) characteristics, which might have great potential in the fields of sensing, imaging, diagnosis and treatment.