Visible light promoted [3+2]-cycloaddition in the synthesis of cyclopenta[b]chromenocarbonitrile derivatives

In the manuscript, a novel method for the preparation of cyclopenta[b]chromenocarbonitrile derivatives via [3+2] cycloaddition reaction of substituted 3-cyanochromones and N-cyclopropyloamines initiated by visible light catalysis in the presence of Eosin Y as a photocatalyst has been described. The key parameters responsible for the success of the described strategy are: visible light, small amount of photoredox catalyst, anhydrous solvent and inert atmosphere.