Magnetic Fe3O4–BF3: highly efficient Lewis acid catalyst for the synthesis of α-aminonitriles

Fe3O4 magnetic nanoparticle-supported BF3 was prepared as a new magnetically separable Lewis acid catalyst and successfully used for the one-pot synthesis of α-aminonitriles. A broad range of substrates including the aromatic and heteroaromatic aldehydes, cyclic ketones (cyclopentanone, cyclohexanone and cycloheptanone), aryl–alkyl ketones, diaryl ketones and tetralones, isatin derivatives and acenaphthenequinone were condensed with amines (aliphatic and aromatic) and trimethylsilyl cyanide. All reactions were completed in short times and products were obtained in good to excellent yields. The catalyst could be recycled and reused several times without any loss of efficiency. Finally, α-aminonitrile containing adenine was successfully synthesized.