Pd/Pivalic Acid Mediated Direct Arylation of 2‐Pyrones and Related Heterocycles

Abstract Direct arylation represents a favourable alternative to traditional cross‐coupling reactions and has found widespread use with simple aryls and robust heterocycles. Herein a direct arylation protocol has been optimised and applied to more delicate, privileged biological motifs. The intramolecular direct arylation of 2‐pyrones, 2‐coumarins, 2‐pyridones and 2‐quinolones occurs in very good to excellent yields using a Pd0 source and pivalic acid as a crucial additive. Preliminary mechanistic investigations were also carried out.