Photo-oxidative Ruthenium(II)-Catalyzed Formal [3 + 2] Heterocyclization of Thioamides to Thiadiazoles
Pragya Pali, Gaurav Shukla, Priya Saha, Maya Shankar Singh
Abstract
An operationally simple and sustainable one-pot photo-oxidative formal [3 + 2] heterocyclization of β-ketothioamides with aryldiazonium salts catalyzed by Ru(bpy)3Cl2 has been realized to provide 2,4-disubstituted 5-imino-1,2,3-thiadiazoles in good to high yields under mild reaction conditions for the first time. The reaction proceeded via an α-phenylhydrazone adduct of thioamides leading to 1,2,3-thiadiazoles via N–S bond formation at room temperature. Notably, the products possess Z-stereochemistry with regard to the exocyclic C═N double bond at the 5-position of the ring.
Topics & Concepts
ThiadiazolesChemistryRutheniumCatalysisAdductRing (chemistry)Double bondOxidative phosphorylationMedicinal chemistryCombinatorial chemistryOrganic chemistryBiochemistrySulfur-Based Synthesis TechniquesSynthesis and Catalytic ReactionsCatalytic C–H Functionalization Methods