A novel tandem Betti/Ullmann oxidation reaction as an efficient route for synthesis of new oxazepine derivatives

A novel tandem Betti/Ullmann/oxidation reaction was used for synthesis of new oxazepine derivatives containing kojic acid. This protocol includes a three-component Betti reaction of 2-naphthol, 2-haloanilines and kojic aldehyde followed by copper-mediated intramolecular Ullmann C-O coupling reaction and subsequently aerobic oxidation. This method provides a new and useful strategy for the construction of heterocycles. Also novel Betti bases based on kojic acid derivatives have been synthesized. In this regard, boric acid functionalized silica supported $$\hbox {Fe}_{3}\hbox {O}_{4}$$ nanoparticle have been designed, synthesized and used as a highly efficient, environmentally benign and recyclable heterogeneous magnetic nanocatalyst for the direct synthesis of desired Betti bases under solvent free conditions. A novel tandem Betti/Ullmann/oxidation reaction was introduced for synthesis of new oxazepine derivatives. This method provides a new and useful strategy for the construction of heterocycles. In this regard, $$\hbox {Fe}_{3}\hbox {O}_{4}$$ @ $$\hbox {SiO}_{2}$$ -boric acid nanoparticles have been synthesized and used for the synthesis of desired novel Betti bases based on kojic acid derivatives.