Oxone® Mediated Regioselective C(sp2)−H Selenylation and Thiocyanation of Pyrazolo[1,5‐a]pyrimidines at Room Temperature

Abstract A mild Oxone® mediated reaction for direct regioselective C−H selenylation and thiocyanation of pyrazolo[1,5‐ a ]pyrimidines is established at ambient temperature. This practical and efficient methodology employs Oxone® as a user friendly, green, non‐toxic and cheap reagent to facilitate selenylation and thiocyanation at room temperature. The present method offers high regioselectivity, broad substrate scope, mild conditions and excellent yields. Further, this eco‐friendly approach could easily be extended for mild C−H selenylation and thiocyanation of other heterocycles. Mechanistic studies indicate that the reaction occurs through electrophilic substitution mechanism via generation of an electrophilic chalcogen species.