Chlorophyll-Catalyzed Visible-Light-Mediated Synthesis of Tetrahydroquinolines from <i>N</i>,<i>N</i>‑Dimethylanilines and Maleimides

Natural pigment chlorophyll was used as a green photosensitizer for the first time in a visible-light photoredox catalysis for the efficient synthesis of tetrahydroquinolines from <i>N</i>,<i>N</i>-dimethylanilines and maleimides in an air atmosphere. The reaction involves direct cyclization via an sp³ C–H bond functionalization process to afford products in moderate to high yields (61–98%) from a wide range of substrates with a low loading of chlorophyll under mild conditions. This work demonstrates the potential benefits of chlorophyll as photosensitizer in visible light catalysis