Access to some C5-cyclised 2 pyrones and 2-pyridones via direct arylation; retention of chloride as a synthetic handle

Abstract

The synthetic effort towards the functionalisation of C-H bonds on 2 pyrones and 2-pyridones has been funnelled by the preferential reactivity of the C-3 position. Herein, we report a direct arylation protocol for the intramolecular coupling of 2 pyrones and 2 pyridones, allowing access to a previously unavailable class of C-5 cyclised products with an unstudied biological profile. A C-Cl bond was retained at C-3 during the direct arylation process allowing further derivatisation at C-3, which we have demonstrated with a proof-of-principle Suzuki-Miyaura cross-coupling reaction.