Piperidine-functionalized Fe 3 O 4 supported graphene quantum dots as an efficient catalyst for the synthesis of 2-aminochromenes under solvent-free conditions

Abstract

Fe 3 O 4 supported graphene quantum dots (GQDs) (Fe 3 O 4 @GQDs) was prepared under microwave irradiation. Piperidine was bound to Fe 3 O 4 @GQDs via its reaction with 3-piperidinopropyltrimethoxysilane and piperidine-functionalized Lewis basic nano-catalyst (Fe 3 O 4 @GQDs-Pip) was prepared. This freshly prepared catalyst was evaluated as a heterogeneous magnetic reusable catalyst for the one-pot synthesis of 2- aminochromenes under MW-assisted solvent-free conditions. Two composite particles, Fe 3 O 4 @GQDs and Fe 3 O 4 @GQDs-Pip were characterized by FT-IR, XRD, SEM, TGA and VSM analytical methods. The catalyst could be easily recovered by magnetic separation and recycled for 5 times without significant loss of its catalytic activity.