Visible Light Promoted [3+2]-Cycloaddition for 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 has been described. The reaction was performed in the presence of Eosin Y as a photocatalyst. The key parameters responsible for the success of the described strategy are visible light, a small amount of photoredox catalyst, an anhydrous solvent, and an inert atmosphere.