meta-Hydroxylation of Pyridines, Quinolines, and Isoquinolines Using Dearomatized Intermediates

The functionalization of C-H bonds in heterocycles holds considerable importance in chemical synthesis and drug discovery. Recently, the regioselective introduction of various functionalities at the meta-position of azines, utilizing readily accessible dearomatized intermediates, has emerged as a highly attractive approach. Along these lines, the meta-hydroxylation of azines is an appealing but challenging transformation due to the inherent electronic nature of these heterocycles. Herein, we report a meta-selective hydroxylation of pyridines, quinolines and isoquinolines through easily accessible oxazinoaza-arene intermediates. The nucleophilic C3-position of these dienamine-type intermediates engages in highly regioselective hydroxylation upon treatment with electrophilic peroxides.