A novel bi-functional metal/solid acid catalyst for the direct reductive amination of nitroarenes synthesized on a resistant mesoporous carbon (CMK-8) support

A metal–acid bi-functional catalyst based on nickel nanoparticles and polystyrene sulfonic acid chains anchored on ordered mesoporous carbon CMK-8 was synthesized through a simple method. This nanocomposite was condignly exploited as a novel metal–solid acid bi-functional heterogeneous catalyst for the one-pot direct reductive amination of aldehydes with nitroarenes. NaBH₄ was used as a mild reducing agent under catalytic hydrogen transfer route. Excellent yields at room temperature and short reaction time in a safe combinatorial solvent (ethanol–H₂O) achieved thanks to the nickel metals and the acidic nature of polymer incorporated in mesoporous channels of CMK-8. The structural properties of the synthesized catalyst were characterized by FT-IR, XRD, TEM, BET, DRS-UV, EDX-Mapping and ICP techniques. Besides being eco-friendly, the method has several advantages such as simple work-up procedure and moderate to high-yield. Reusability of the catalyst explicates the acceptable stability of the nanocomposite after ten runs without noticeable loss of activity.