Iron(iii) chloride-promoted cyclization of α,β-alkynic tosylhydrazones with diselenides: synthesis of 4-(arylselanyl)-1H-pyrazoles

Abstract

A highly efficient iron(III) chloride-promoted cyclization between α,β-alkynic tosylhydrazones and diselenides to form a 4-(arylselanyl)-1H-pyrazole skeleton is studied. This reaction forms C–N and C–Se bonds in one step by utilizing inexpensive iron(III) chloride instead of expensive transition metal additives. This strategy features easily synthesized substrates, mild reaction conditions and high tolerance to functional groups.