Transition-metal-free, direct C[sbnd]H radical trifluoromethylation of nitroimidazoles with Togni’s reagent

Abstract

Trifluoromethyl moiety in bioactive compounds can dramatically change both the physicochemical and physiological properties, which could further improve both the pharmacokinetic and pharmacological profiles. It has therefore become indispensable to develop an efficient and mild synthetic methodology for the incorporation of trifluoromethyl group. In present study, a green, mild and practical method which allows for the transition-metal-free, direct CH radical trifluoromethylation of nitroimidazoles with Togni’s regent II as the CF3 radical precursor is described. Diverse nitroimidazoles and their drug molecules were smoothly transformed into trifluoromethylated compounds in moderate to good yields under mild conditions. This new method provides an alternative approach for the prepare of trifluoromethylated compounds, as well as late-stage modification of bioactive nitroimidazoles.