Chemoselective Nitro Reduction Using Nitrogen-Doped Carbon-Encapsulated Ni Catalyst and Y-Type Packed Bed Column for Continuous Flow Reaction

Selective reduction of nitro-containing arenes and heteroarenes was achieved in 5 minutes at room temperature utilizing inexpensive NaBH4 as a hydrogen source and a newly developed Ni@N-C catalyst, obtained via a simple carbon coating process without the need for an external carbon source. A wide variety of nitro derivatives, including pharmaceutical molecules, was successfully reduced to the corresponding amines in yields ranging from 45% to 99% using the Ni@N-C catalyst under general batch conditions. The reactivity and selectivity of the nitro reduction were further enhanced by a continuous flow reaction system, especially when a newly designed Y-type column was used, and the Osimertinib intermediate was produced on gram scale after 24 hours without any nickel metal contamination or silica gel chromatography purification.