Ligand-Promoted Pd-Catalyzed Oxime Ether Directed C-H Hydroxylation of Arenes

An efficient Pd-catalyzed oxime ether directed ortho C-H hydroxylation of arenes under neutral conditions has been developed. The efficiency of this hydroxylation is significantly improved by a ligand. Oxone, an inexpensive, readily available, and safe reagent, was employed as terminal oxidant and oxygen source. The challenging electron-deficient substrates could also be monohydroxylated in high efficiency. Drug modification with this protocol was also successfully demonstrated.