Versatile synthesis of isocoumarins and α-pyrones by ruthenium-catalyzed oxidative C-H/O-H bond cleavages

Abstract

An inexpensive cationic ruthenium(II) catalyst enabled the expedient synthesis of isocoumarins through oxidative annulations of alkynes by benzoic acids. This C-H/O-H bond functionalization process also proved applicable to the preparation of α-pyrones and was shown to proceed by rate-limiting C-H bond ruthenation.