Magnetically recyclable Cu-BTC@Fe3O4-catalyzed synthesis of cyano functionalized chroman-4-ones

An intramolecular radical cascade acyl-cyanation of o-(allyloxy)benzaldehydes with Me₃SiCN using magnetically recyclable Cu-BTC@Fe₃O₄ catalyst (BTC = 1,3,5-benzenetri- carboxylate) and peroxides as the stoichiometric oxidants affords 3-cyanomethyl-functionalized chroman-4-ones in moderate to good yields. The catalyst can be readily recovered with an external permanent magnet, with slight decrease in its activity after successive five runs.