Dual organic dyes as a pseudo-redox mediation system to promotion of tandem oxidation /[3+2] cycloaddition reactions under visible light

Abstract An atom- and step-economy protocol has been developed to synthesize some new biologically active pyrrolo[2,1-a]isoquinoline alkaloids via redox mediation system under visible light irradiation. A vast variety of double and triple bonds, as dipolarophiles, treated with in situ generated azomethine ylides to prepare corresponding products in good to excellent yields. This metal-free method effectively promoted oxidation/[3 + 2] cycloaddition/oxidative/aromatization domino reaction without further oxidant using dual organic dyes as pseudo-redox mediation system. Besides, for most of the products, product precipitate was readily separated from reaction media. To the best of our knowledge, this is the first report of dual dyes as a pseudo-redox mediation system.