An Efficient Method for Aryl Nitro Reduction and Cleavage of Azo Compounds Using Iron Powder/Calcium Chloride

A novel, efficient Fe/CaCl2 system is revealed for the reduction of nitroarenes and reductive cleavage of azo compounds by catalytic transfer hydrogenation (CTH). The selective reduction of nitro compounds in the presence of sensitive functional groups including halides, carbonyl, hydroxyl, aldehyde, methyl, methoxy, acetyl, nitrile, and ester substituents with an excellent yields is reported. The simple experimental procedure and easy purification make the protocol advantageous.