Catalytic synthesis of coumarin-linked nicotinonitrile derivatives via a cooperative vinylogous anomeric-based oxidation

In the presented study, we developed a new and efficient strategy for the synthesis of coumarin-linked nicotinonitrile derivatives via a cooperative vinylogous anomeric-based oxidation mechanism. Target compounds were prepared through a four component reaction between aldehyde derivatives, 2-acetyl-3H-benzo[f]chromen-3-one or 3-acetylcoumarin, malononitrile or ethyl cyanoacetate and ammonium acetate, in the presence a catalytic amount of Fe3O4@SiO2@(CH2)(3)-urea-benzimidazole with sulfonic acid tags as a recoverable nanomagnetic catalyst. All reactions proceed smoothly with good to high yields under solvent free conditions. Graphic abstract Fe3O4@SiO2@(CH2)3-urea-benzimidazole with sulfonic acid tags shows elegant catalytic activity for the preparation of coumarin linked nicotinonitrile derivateives via a cooperative vinylogous anomeric based oxidation mechanism.