Synthesis of various and interesting heterocycles included berberino derivatives

To reach heterocyclic systems is of considerable ongoing interest. With this aim, I investigated the usefulness of 1,2-diaza-1,3-dienes (DDs) in the construction of several five- and six-membered heteroring systems. During my activities, I developed new methodologies for the synthesis of hydroxydihydrothiazines, tetrahydropyrrolo[3,4-c]pyridinetriones, dihydrothiophenes and thiophenes. All of these procedures furnish a better way to build several heterorings with a large scaffold diversity in very mild conditions. In addition, I developed a procedure that furnished the γ-selective addition of several nucleophiles to cyclic conjugated N-acyliminium ions. To conclude, I applied my knowledge in the field of DDs to an interesting natural bioactive compound, berberine. I obtained numerous berberino-derivatives; besides the synthesis, we also have tested the antioxidant activity with ORAC, DNA nicking assay and DFCH-DA assay method.