Remote Para-C-H Acetoxylation of Electron-Deficient Arenes.

One formidable challenge in sp2 C-H activation is how to achieve high para selectivity on electron-deficient arenes because such site selectivity is disfavored by the electronic bias induced by the electron-withdrawing groups. The first highly selective para-C-H acetoxylation of various benzoic acids using a nitrile-based template was realized. Removal of the template leads to para-hydroxylated benzoic acids, which are versatile intermediates for a wide range of synthetically useful transformations.