Hexafluoro-2-propanol-assisted quick and chemoselective nitro reduction using iron powder as catalyst under mild conditions

Abstract

Hexafluoro-2-propanol as the promoter for the quick nitro reduction using a combination of iron powder and 2N HCl aqueous solution is reported. This methodology has several positive features, as it is of room temperature, remarkably short reaction time. A wide range of substrates including those bearing reducible functional groups such as aldehyde, ketone, acid, ester, amide, nitrile, halogens, even allyl, propargyl and heterocycles are chemoselectively reduced in good to excellent yields, even on gram scale. Notably, the highly selective reduction of 3-nitrophenylboronic acid is achieved quantitatively. The reduction is also tolerant of common protecting groups, and aliphatic nitro compound, 1-nitrooctane can be reduced successfully.