Iron(III) Triflimide as a Catalytic Substitute for Gold(I) in Hydroaddition Reactions to Unsaturated Carbon–Carbon Bonds

Abstract

In this work it is shown that iron(III) and gold(I) triflimide efficiently catalyze the hydroaddition of a wide array of nucleophiles including water, alcohols, thiols, amines, alkynes, and alkenes to multiple C-C bonds. The study of the catalytic activity and selectivity of iron(III), gold(I), and Brønsted triflimides has unveiled that iron(III) triflimide [Fe(NTf2)3] is a robust catalyst under heating conditions, whereas gold(I) triflimide, even stabilized by PPh3, readily decomposes at 80 °C and releases triflimidic acid (HNTf2) that can catalyze the corresponding reaction, as shown by in situ (19)F, (15)N, and (31)P NMR spectroscopy. The results presented here demonstrate that each of the two catalyst types has weaknesses and strengths and complement each other. Iron(III) triflimide can act as a substitute of gold(I) triflimide as a catalyst for hydroaddition reactions to unsaturated carbon-carbon bonds.