Simple reversible fixation of a magnetic catalyst in a continuous flow system: ultrafast reduction of nitroarenes and subsequent reductive amination using ammonia borane

Abstract

Continuous reductive amination of aldehydes with nitroarenes over a Pd–Pt–Fe₃O₄ catalyst was performed. We used NH₃BH₃ as not only a hydrogen source for nitro reduction, but also a reductant for imine reduction. Secondary aromatic amines were obtained in the continuous flow reaction in good to excellent yields.