A Facile Method for the Synthesis of Thiazolium Salts Using P2S5-Py2 Complex and Their Application in Intermolecular Stetter Reactions
An expedient method to prepare thiazolium salts using the P2S5-Py2 complex has been studied. A variety of thiazolium salts can be rapidly accessed by the clean reaction between readily available α-formamido ketones and the P2S5-Py2 complex. Following salt metathesis with sodium tetrafluoroborate or sodium tetraphenylborate, the pure thiazolium salts are obtained via simple filtration. This method is suitable for a variety of substituents on the heterocycle. Reactions using the P2S5-Py2 complex have been compared with other commonly used thionating methods including Lawesson’s reagent and phosphorus decasulfide. The thiazolium precatalysts were then applied in the intermolecular Stetter reaction to test their catalytic activity and to identify the most active thiazolium salt. As a result, the N-Cy thiazolium salts were obtained in the highest yield following the above synthetic pathway, whereas the intermolecular Stetter reaction was catalyzed by N-mesityl thiazolium salts in the highest yield.
Synthesis of Thiazolium Salts, Intermolecular Stetter Reactions
Master of Science (M.Sc.)