Green Approach for the Domino Reduction/Reductive Amination of Nitroarenes and Chemoselective Reduction of Aldehydes Using Fe/aq. Citric Acid/Montmorillonite K10

Abstract

AbstractWe have developed a new and mild method for the direct one‐pot reduction/reductive amination of nitroarenes with arylaldehydes using Fe/aq citric acid/montmorillonite K10 catalytic system under ambient conditions. This catalyst has excellent functional group compatibility and the reaction provides rapid access to a diverse range of secondary amines. Under the conditions, aromatic aldehydes are selectively reduced to benzyl alcohols in the presence of ketones. A concise and efficient approach to the synthesis of diverse range of 1,2‐disubstituted benzimidazoles has also been accomplished for the first time from 1,2‐dinitrobenzene and aromatic aldehydes using the above catalytic system. The method involves the domino nitro reduction/cyclization/reduction cascade.