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

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.

Automated summary

A NaI-promoted sequential double carbon-sulfur bond formation method was developed using Deoxofluor as the sulfur source, allowing for the synthesis of sulfur-bridged imidazopyridines in a short amount of time at room temperature. This unique approach also enables the transformation of imidazo[1,5-a]pyridines into 1,2,4-thiadiazoles in the presence of ammonium salt, forming both carbon-sulfur and nitrogen-sulfur bonds without the need for transition metals under mild conditions.