Magnetic nanoparticle-supported phosphine gold(i) complex: a highly efficient and recyclable catalyst for the direct reductive amination of aldehydes and ketones

Abstract

The direct reductive amination of aldehydes and ketones has been achieved in dichloromethane at room temperature by using a magnetic nanoparticle-supported phosphine gold(I) complex [Fe₃O₄@SiO₂-P–AuCl] as the catalyst and ethyl Hantzsch ester as the hydrogen source, yielding a variety of secondary amines in excellent yields under neutral conditions. The new heterogeneous gold catalyst can be prepared by a simple procedure from commercially readily available reagents and can easily be separated from the reaction mixture by applying an external magnet and recycled at least 10 times without any loss of activity.