NIS-promoted carbochalcogenation of styrenes: regioselective C-3 alkylation of pyrazolo[1,5-a]pyrimidines

Abstract

An N-iodosuccinimide (NIS) mediated transition metal and solvent-free, regioselective multicomponent cascade reaction is developed for the C-3 alkylation of pyrazolo[1,5-a]pyrimidines via a three-component reaction of styrenes, diaryl dichalcogenides and pyrazolo[1,5-a]pyrimidines. This operationally simple, cost-effective and rapid reaction furnishes C-3 functionalized pyrazolo[1,5-a]pyrimidines in good to excellent yields. The reaction is scalable and operates via an electrophilic substitution mechanism.