Togni reagent II
Other names: 1-(trifluoromethyl)-1λ3,2-benziodoxol-3(1H)-one
C8H4F3IO2
5/50 
common
The Togni Reagent II, developed in 2006, is a hypervalent iodine compound that serves as a versatile electrophilic trifluoromethylation reagent. This reagent serves as a comparatively mild electrophilic source of the trifluoromethyl moiety, –CF3. This functional group is used ubiquitously in pharmaceutical drug discovery, both for its pharmacokinetic and legal effects – as a bioisostear of aliphatic nitro groups. Structurally, Togni Reagent II is noteworthy for its unusual hypervalent λ3 iodine center. Unlike some other electrophilic trifluoromethylation sources such as trifluoroiodomethane (CF3I) or the Ruppert-Prakash reagent (trifluoromethyltrimethylsilane, TMS-CF3), Togni Reagent II is a crystalline solid that is stable at room temperature, making it significantly easier and safer to handle.