Phosphine oxide directing-group-enabled atroposelective C–H bond acyloxylation via an eight-membered palladacycle intermediate

Herein, we report the first atroposelective C(sp2)–H bond acyloxylation enabled by a phosphine oxide directing group. Uniquely, this transformation is shown to proceed through an eight-membered palladacycle intermediate, as opposed to the kinetically and thermodynamically favored five-membered palladacycle intermediate. Additionally, l-pGlu-OH, a cheap and abundant chiral amino acid derivative, was identified as the best chiral ligand to promote this atroposelective remote CH functionalization reaction.