Heterogeneous copper ferrite nanoparticles for catalytic synthesis of tetrahydroquinolines

Methods for using commercially available copper ferrite nanoparticles for organic transformations have witnessed emerging development. Herein we expand the application of such material for heterogeneously catalytic annulation of N,N-dimethylaniline and maleimides to yield tetrahydroquinolines. Using the developed conditions, a 73% yield of tetrahydroquinoline derived from N-benzylmaleimide and 4,N,N-trimethylaniline was isolated. Derivatives bearing fluoro, thiophenyl, and alpha-methylbenzyl groups were also obtained with yields varying from 54% to 80%. The copper ferrite nanoparticles could be easily separated after the reaction and showed nearly identical XRD result compare to that of the fresh material.