Metal-free, room temperature, acid-K₂S₂O₈ mediated method for the nitration of olefins: an easy approach for the synthesis of nitroolefins

Abstract

Here, we have developed a simple, room temperature method for the nitration of olefins by using inexpensive sodium nitrite as a source of nitro groups in the presence of trifluoroacetic acid (TFA) and potassium persulfate (K₂S₂O₈) under an open atmosphere. Styrenes and mono-substituted olefins give stereo-selective corresponding <i>E</i>-nitroolefins under optimized conditions, however, 1,1-bisubstituted olefins give a mixture of <i>E</i>- and <i>Z</i>-nitroolefins. The optimized conditions work well with electron-donating, electron-withdrawing, un-substituted and heterocyclic styrenes and mono-substituted olefins and give corresponding nitroolefins with good to excellent yields.