Cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids

Abstract

The first cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids has been developed. This operationally simple protocol allows rapid access to synthetically useful coumarins on gram scale by employing CeCl₃ as a photocatalyst and O₂ as a terminal oxidant. Overall, this delivers an economical and environmentally amiable entry to diversely substituted coumarins, important structural motifs in bioactive molecules.