Copper Pyrrole‐imine Incorporated Fe3O4‐Nanocomposite: A Magnetically Separable and Reusable Catalyst for the Oxidative Amination of Aryl Aldehydes

Abstract

AbstractThe present work represents the fabrication of a Fe3O4‐based nanocomposite Fe3O4@CS@PyL‐imin@Cu and its application towards oxidative amination of aryl aldehydes to important amides. First, magnetic Fe3O4 was coated with chitosan (CS) and then treated with pyrrole‐2‐carboxaldehyde that produces the desired magnetic nanocatalyst by depositing Cu on its pyrrole‐imine functionalized surface. The structure and property of the nanocatalyst are confirmed by all physicochemical technics. The Cu‐based magnetic nanocatalyst shows excellent catalytic efficiency toward the oxidative amination of aldehydes with secondary amines to produce corresponding amides (up to 97 % yield) in presence of environmentally benign oxidant H2O2. The magnetic nanocatalyst is easily separable with an external magnet and reusable up to the 5th catalytic cycle without any significant loss of catalytic activity. Overall, a low loading (1.5 mol % of Cu) nanocatalyst has proven to be a practical approach to an alternative to the existing protocol for the preparation of amides.