Iodide-promoted transformations of imidazopyridines into sulfur-bridged imidazopyridines or 1,2,4-thiadiazoles

Chem Commun (Camb). 2021 May 27;57(43):5338-5341. doi: 10.1039/d1cc01044a.

Abstract

A NaI-promoted sequential double carbon-sulfur bond formation was developed to afford sulfur-bridged imidazopyridines, using Deoxofluor as the sulfur source and requiring only 15 min at room temperature. Using this process, imidazo[1,5-a]pyridines could also be transformed to 1,2,4-thiadiazoles in the presence of ammonium salt with the formation of both carbon-sulfur and nitrogen-sulfur bonds. This mechanistically unique method is distinguished by its wide substrate scope, lack of requirement for transition metals and mild conditions.