Ipso-Nitration of Boronic Esters Enabled by Ferric Nitrate Nonahydrate (Fe(NO3)3·9H2O) in HFIP

We describe in this work an operationally facile and generally applicable ipso-nitration of boronic esters by Fe(NO3)3·9H2O in hexafluoroisopropanol (HFIP), allowing us fast access to various nitroarenes that are currently difficult to obtain via traditional electrophilic C–H nitrations. In contrast to previous deborylative ipso-nitrations, this new protocol utilized less reactive and more stable organoboron reagents and therefore had significantly improved substrate scope and functional group tolerance, which was exemplified in the late-stage ipso-nitration of various natural products, pharmaceuticals, and biologically active molecules.